WO2006129865A1

WO2006129865A1 - Substrate for electronic devices, electronic device provided with the substrate and electronic equipment provided with the electronic device

Info

Publication number: WO2006129865A1
Application number: PCT/JP2006/311369
Authority: WO
Inventors: Harunobu Komatsu
Original assignee: Seiko Epson Corporation
Priority date: 2005-06-01
Filing date: 2006-05-31
Publication date: 2006-12-07
Also published as: JP2006339328A

Abstract

The object of the present invention is to provide a substrate for electronic devices having an excellent carrier transport ability, an electronic device which is provided with the substrate and which can exhibit excellent characteristics, and electronic equipment having high reliability. The substrate for electronic devices 1 includes an organic semiconductor layer 5 mainly comprised of an organic semiconductor material having at least one conjugated structure, an electrode 3 containing metal atoms, and an intermediate layer 4 provided between the organic semiconductor layer 5 and the electrode 3 in contact with both the organic semiconductor layer 5 and the electrode 3. The intermediate layer 4 contains as its major component a ligand having at least one conjugated structure and at least one ligand atom that coordinates to one of the metal atoms.

Description

DESCRIPTION

SUBSTRATE FOR ELECTRONIC DEVICES, ELECTRONIC DEVICE PROVIDED WITH THE SUBSTRATE AND ELECTRONIC EQUIPMENT PROVIDED WITH THE ELECTRONIC DEVICE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims a priority to Japanese Patent Application No. 2005-160992 filed on June 1, 2005 which is hereby expressly incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a substrate for electronic devices, an electronic device having the substrate and electronic equipment provided with the electronic device.

Description of the Prior Art

As an electronic device having an organic semiconductor layer and an electrode which are provided so as to be in contact with each other, there are known an organic electroluminescent device (hereinafter, simply referred to as an "organic EL device" or "organic EL element") and an organic thin film transistor and the like.

In these electronic devices , the organic EL devices have been extensively developed in expectation of their use as solid-state luminescent devices or emitting devices (semiconductor devices) for use in inexpensive large full-color displays .

In general, such an organic EL device has a structure in which a light emitting layer is provided between a cathode and an anode . When an electric field is applied between the cathode and the anode, electrons are injected into the light emitting layer from the cathode side, and holes are injected into the light emitting layer from the anode side.

The injected electrons and holes are recombined in the light emitting layer, which then causes their energy level to return from the conduction band to the valence band. At this time, excitation energy is released as light energy so that the light emitting layer emits light.

In such organic EL devices, it has been known that a layered device structure, in which organic layers formed of organic materials having different carrier transport properties for electrons or holes are provided between a light emitting layer and a cathode and/or an anode, is effective in obtaining a high-efficiency organic EL device with high luminance .

Therefore, various researches and developments are made for organic EL devices provided with a substrate (laminated body) for electronic devices in which a light emitting layer and organic semiconductor layers having different carrier transport abilities are laminated on an electrode containing metal atoms. However, characteristics of the organic EL devices such as luminescent efficiency, color purity of emitted lights, pattern precision and the like have not yet been improved to. a satisfactory level that meets the expectations in actuality (see, for example, JP-A No. 9-255774).

In view of such a problem, a further research has been made, and as a result it has been found that transfer of carriers is not carried out smoothly because of the following factors : (1) there is a large difference between the carrier transport abilities of the organic semiconductor material and the metal atoms, and (2) since interaction between the organic semiconductor materials is larger than interaction between the semiconductor material and the metal atoms , sufficient adhesion can not be obtained between the organic semiconductor layer and the electrode.

In order to solve this problem, there is disclosed a method in which a hole injection layer containing as its main ingredient a complex such as copper phthalocyanine is formed between an anode and a hole transport layer (organic semiconductor layer) to improve a carrier transport ability (see, for example, JP-A 2002-151269).

However, even in the case where such a method is employed, characteristics of the organic EL devices are not satisfactorily improved since the hole injection layer is formed so that the complexes coordinate substantially perpendicularly to the anode.

These problems described above may also been raised in organic thin film transistors .

SUMMARY OF THE INVENTION

It is therefore an object of the present invention is to provide a substrate for electronic devices having an excellent carrier transport ability, an electronic device which is provided with the substrate and which can exhibit excellent characteristics, and electronic equipment having high reliability.

In order to achieve the above object, the present invention is directed to a substrate for electronic devices, which includes an organic semiconductor layer mainly comprised of an organic semiconductor material having a conjugated structure; an electrode containing metal atoms; and an intermediate layer provided between the organic semiconductor layer and the electrode in contact with both the organic semiconductor layer and the electrode, wherein the intermediate layer contains as its major component. a ligand having at least one conjugated structure and at least one ligand atom that coordinates to one of the metal atoms .

According to the present invention described above, it is possible to provide a substrate for electronic devices which has an excellent carrier transport ability.

In the substrate for electronic devices according to the present invention, it is preferred that the total number of carbon atoms in the ligand is 40 or less.

This makes it possible to appropriately prevent a sterile hindrance between adjacent ligands from being enlarged when each ligand coordinates to the metal atom. Consequently, it becomes possible to coordinate the ligand to the metal atom effectively.

Further, in the substrate for electronic devices according to the present invention, it is preferred that the ligand is a unidentate ligand having one ligand atom that coordinates to the metal atom.

By selecting a unidentate ligand as the ligand, it is possible to prevent appropriately a sterile hindrance between the adjacent unidentate ligands from being enlarged. As a result, the. ligands can coordinate to the metals atoms of the electrode effectively.

Furthermore, in the substrate for electronic devices according to the present invention, it is also preferred that the unidentate ligand is of the type that the ligand atom is contained in the conjugated structure.

This makes it possible to incorporate carriers which have been injected from the electrode through the metal atoms to which the ligand atom(s) coordinate into the conjugated structures appropriately and smoothly. As a result, the carriers can also be injected into the organic semiconductor layer having the conjugated structures appropriately and smoothly.

In the substrate for electronic devices according to the present invention, it is also preferred that the ligand is a multidentate ligand having two or more ligand atoms which coordinate to the metal atom.

By selecting a multidentate ligand as the ligand, two or more ligand atoms can coordinate to one metal atom so that the bonding of the ligands in the intermediate layer and the metal atoms can be made stably as compared to the case where one ligand atom is coordinated. As a result, it is possible to reliably transfer the carriers which have been injected through the metal atoms to the side of the conjugated structures.

In the substrate for electronic devices described above, it is also preferred that the multidentate ligand is of the type that all the ligand atoms are contained in the conjugated structure.

By using this type of ligand, it is possible to reliably transfer the carriers which have been injected through the metal atoms to the side of the conjugated structures. As a result, the injection of the carriers into the organic semiconductor layer through the conjugated structures can be carried out appropriately and smoothly.

In this case, it is preferred that the multidentate ligand is composed of at least one of compounds represented by the following general formulas ( 1 ) and ( 2 ) :

(1) (2)

wherein in each of the general formulas two substituents A⁰S are the same or different and each independently represents a hydrogen atom, a chlorine atom, a carboxy group, a hydroxy group, or a straight-chain alkyl group having 1 to 10 carbon atoms .

By selecting such compounds, it is possible to reliably transfer carriers that have been injected into the intermediate layer to the side of the conjugated structures appropriately and smoothly. As a result, the injection of the carriers into the organic semiconductor layer through the conjugated structures can also be carried out appropriately and smoothly.

Further, in this case, it is also preferred that the straight-chain alkyl group has 2 to 8 carbon atoms.

This makes it possible to coordinate the ligand atoms to the metal atom reliably while preventing appropriately the adjacent conjugated structures from being closely approached. As a result, it is possible to reliably transfer carriers that have been injected into the conjugated structures through the ligand atoms in the thickness direction without causing the carriers to be moved in the intermediate layer in the surface direction thereof.

Further, in this case it is also preferred that in each of the compounds each substituent A°s is bonded to a pyridine ring at its 3 or 4-position. This makes it possible to coordinate the two nitrogen atoms (ligand atoms) to the metal atom reliably.

Furthermore, in the substrate for electronic devices according to the present invention, it is also preferred that the multidentate ligand is of the type that a part of the ligand atoms is contained in the conjugated structure.

By using this type of ligand, it is possible to reliably transfer carriers that have been injected into the intermediate layer through the metal atoms to the side of the conjugated structures appropriately and smoothly. As a result, the injection of the carriers into the organic semiconductor layer through the conjugated structures can also be carried out appropriately and smoothly.

In this substrate for electronic devices described above, it is also preferred that the multidentate ligand is composed of at least one of compounds represented by the following general formulas (3) to (9):

where in each of the general formulas a substituent X represents a nitrogen atom, an oxygen atom, a sulfur atom, or a selenium atom, a substituent Y⁰ represents a hydroxy group, a mercapto group, an amino group or a carboxy group, and a substituent Z⁰ represents a hydrogen atom, a chlorine atom, or a straight-chain alkyl group having 1 to 10 carbon atoms.

By selecting such compounds as the ligand, it is possible to reliably transfer carriers that have been injected from the electrode through the metal atoms to the side of the conjugated structures appropriately and smoothly at the ligand atoms contained in the conjugated structures. As a result, the injection of the carriers into the organic semiconductor layer through the conjugated structures can also be carried out appropriately and smoothly.

In this case, it is preferred that the straight-chain alkyl group has 2 to 8 carbon atoms .

This makes it possible to coordinate the ligand atoms to the metal atoms reliably while preventing appropriately the adjacent conjugated structures from being closely approached. As a result, it is possible to reliably transfer carriers that have been injected into the conjugated structures through the ligand atoms in the thickness direction without causing the carriers to be moved in the intermediate layer in the surface direction thereof.

In this case, it is also preferred that when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas (3), (8) and (9), and the substituent Z⁰ is bonded to a benzene ring at its 3 or 4 position.

In the case of the compound represented by the general formula (3)-, use of such a ligand makes it possible to coordinate the ligand atom and the nitrogen atom to the metal atom reliably. Further, in the case of the compound represented by the above-mentioned general formula (8) or (9) , use of such a ligand makes it possible to coordinate the ligand atom contained in the substituent Y⁰ and the ligand atom X⁰ to the metal atom reliably.

Further, in this case, it is also preferred that when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas (4) and (5) , and the substituent Z⁰ is bonded to a heteroaromatic ring at its 3 or 4 position.

In the case of the compound represented by the above-mentioned general formula (4) , use of such a ligand makes it possible to coordinate the ligand atom contained in the substituent Y⁰ and the ligand atom X⁰ to the metal atom reliably. Further, in the case of the compound represented by the above-mentioned general formula (5) , use of such a ligand makes it possible to coordinate the ligand atom contained in the substituent Y⁰ and the nitrogen atom to the metal atom reliably.

Further, in this case, it is also preferred that when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas (6) and (7) , the substituent Z⁰ is bonded to a benzene ring at its 4 or 5 position.

This makes it possible to coordinate the ligand atom contained in the substituent Y⁰ and the ligand atom X⁰ reliably.

Further, in the substrate for electronic devices according to the present invention, it is also preferred that the multidentate ligand is of the type that all of the ligand atoms are existed out of the conjugated structure.

In the case where such a multidentate ligand is used, the ligand atoms are contained in the substituents existing outside the conjugated structure. As a result, the ligand atoms can be rotated (moved) about the atoms in the conjugated structure to which the substituents are bonded, respectively. Therefore, the size of the distance between the ligand atoms can be adjusted so as to meet with the size of the atomic radium of the metal atom so that the two ore more ligand atoms can be coordinated to the metal atom reliably. In this case, it is preferred that the multidentate ligand is composed of a compound represented by the following general formula (10) :

(10)

where two substituents Y⁰S are the same or different and each independently represents a hydroxy group, a mercapto group, an amino group or a carboxy group, and a substituent Z⁰ represents a hydrogen atom, a chlorine atom, or a straight-chain alkyl group having 1 to 10 carbon atoms.

In the case where such a compound is used, the ligand atoms are contained in the substituents Y⁰ existing outside the conjugated structure. As a result, the ligand atoms can be rotated (moved) about the atoms in the conjugated structure to which the substituents Y⁰ are bonded, respectively. Therefore, the size of the distance between the ligand atoms can be adjusted so as to meet with the size of the atomic radium of the metal atom so that the two ore more ligand atoms can be coordinated to the metal atom reliably.

This makes it possible to coordinate the ligand atoms to the metal atom reliably while preventing appropriately the adjacent conjugated structures from being closely approached. As a result, it is possible to reliably transfer carriers that have been injected into the conjugated structures through the ligand atoms in the thickness direction of the intermediate layer without causing the carriers to be moved in the intermediate layer in the surface direction thereof.

Further, in this case, it is also preferred that the substituent Z⁰ is bonded to a benzene ring at its 3 or 4 position.

This makes it possible to coordinate the ligand atoms contained in the substituents Y⁰ to the metal atom reliably.

In the substrate for electronic devices according to the present invention, it is also preferred that the metal atom is indium.

In the case where indium is selected as the metal atom, any one of the compounds represented by the above-mentioned general formulas (1) to (3) is selected as the ligand. This makes it possible to improve adhesion between the electrode and the intermediate layer.

Further, in the substrate for electronic devices according to the present invention, it is also preferred that the organic semiconductor material is comprised of a polymer obtained by polymerizing monomers each having at least one polymerizable group at their polymerizable groups .

By forming the organic semiconductor material in this way, the polymer is formed so that it interweaves with the conjugated structures of the intermediate layer when the monomers are polymerized. This makes it possible to improve adhesion between the intermediate layer and the organic semiconductor layer further.

Moreover, in the substrate for electronic devices according to the present invention, it is also preferred that each of the monomers is a compound represented by the following general formula (Al) or (A2)

wherein two R¹S are the same or different and each independently represents a straight-chain alkyl group having 2 to 8 carbon atoms , and four R²S are the same or different and each independently represents a hydrogen atom, a methyl group or an ethyl group, Y represents a group containing at least one substituted or unsubstituted aromatic hydrocarbon ring or substituted or unsubstituted heterocycle, and two X¹S are the same kind of substituent represented by any one of the following general formulas (Bl) to (B3), in which the number of carbon atoms of the two X¹S are the same as or different from to each other; or

wherein eight R³S are the same or different and each independently represents a hydrogen atom, a methyl group, or an ethyl group, Y represents a group containing at least one substituted or unsubstituted aromatic hydrocarbon ring or substituted or unsubstituted heterocycle, and X², X³, X⁴ and X⁵ are the same kind of substituent which is represented by any one of the following general formulas (Bl) to (B3), in which the number of carbon atoms of X², X³, X⁴ and X⁵ are the same as or different from to each other;

wherein n¹ is an integer of 2 to 8 , n² is an integer of

3 to 8 , m is an integer of 0 to 3, Z¹ represents a hydrogen atom oorr aa mmeetthhyyll ggrroouupp,, aanndd ZZ²² represents a hydrogen atom, a methyl group or an ethyl group.

By using these compounds , a polymer is formed so that it interweaves with the conjugated structures of the intermediate layer when the monomers are polymerized. As a result, it is possible to.improve adhesion between the intermediate layer and the organic semiconductor layer further.

Another aspect of the present invention is directed to an electronic device provided with the substrate for electronic devices described above.

This makes it possible to provide an electronic device which is provided with a substrate for electronic devices having an excellent carrier transport ability and which can exhibit excellent characteristics. In this case, it is preferred that the electronic device is an organic EL device .

Such an organic EL device can have an excellent carrier transport ability.

Other aspect of the present invention is directed to electronic equipment provided with the electronic device described above .

Such electronic equipment can have high reliability.

These and other objects, structures and advantages of the present invention will be apparent upon reading the following detailed description of the invention and the examples thereof with reference to the accompanying drawings .

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view which shows one example of a substrate for electronic devices according to the present invention;

FIG. 2 is a cross-sectional view of an organic EL device which is one example of the electronic device according to the present invention;

FIG.3 is a cross-sectional view of a display device which is provided with a number of organic EL devices;

FIG. 4 is a perspective view which shows the structure of a personal mobile computer (or a personal notebook computer) which is one example of the electronic equipment according to the present invention;

FIG. 5 is a perspective view which shows the structure of a mobile phone (including the personal handyphone system (PHS)) which is the other example of the electronic equipment according to the present invention; and

FIG. 6 is a perspective view which shows the structure of a digital still camera which is still other example of the electronic equipment according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

In view of the problems mentioned above, the inventors of this application have made researches earnestly, and as a result , they have conceived that in order to smoothly transfer carriers between an electrode containing metal atoms and an organic semiconductor layer which is mainly constituted of an organic semiconductor material having a conjugated structure, an intermediate layer is provided therebetween so as to be in contact with both the electrode and the organic semiconductor layer, and the intermediate layer is constituted of a material containing as its main component a ligand having a conjugated structure and ligand atoms that coordinate to one of the metal atoms .

By providing such an intermediate layer, since the ligand atoms coordinate to the metal atom so that the ligand is chemically bonded to the metal atom, that is, to the surface of the electrode. With this result, the intermediate layer can exhibit excellent adhesion with the electrode. Further, it is possible to make the difference between the carrier transport abilities of the electrode and the intermediate layer in the vicinity of the boundary therebetween small .

Further, since the ligand has a conjugated structure, it exhibits excellent compatibility to the organic semiconductor material having a conjugated structure. As a result, the intermediate layer can also exhibit excellent adhesion with the organic semiconductor layer. Further, since both of these layers have a conjugated structure, it is possible to make the difference between the carrier transport abilities of these layers small .

In the substrate for electronic.devices having the above structure, it has been found that when carriers (holes or electrons) are moved from the electrode toward the side of the organic semiconductor layer, the above effects can be obtained synergistically, so that the carriers which have been injected into the intermediate layer from the electrode are successively transferred from the ligand atoms to the conjugated structures in the intermediate layer, and then the carriers are moved to the organic semiconductor layer smoothly. Namely, it has been found that the substrate for electronic devices in which the intermediate layer having the above structure is provided between the electrode and the intermediate layer can exhibit an excellent carrier transport ability.

The present invention has been made in view of this finding, and thus the feature of the present invention is directed to a substrate for electronic devices which includes an organic semiconductor layer, an electrode, and an intermediate layer provided between the organic semiconductor layer and the electrode, wherein the intermediate layer is constituted of a material containing as its major component a ligand having ligand atoms and a conjugated structure.

Hereinbelow, the substrate for electronic devices, the electronic device, and the electronic equipment according to the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings.

First, a preferred embodiment of the substrate for electronic devices according to the present invention will be described.

FIG. 1 is a cross-sectional view which shows one example of the substrate for electronic devices. The substrate for electronic devices 1 shown in FIG. 1 includes a substrate 2, an electrode 3 provided on the substrate 2 , an intermediate layer 4 provided on the electrode 3 , and an organic semiconductor layer 5 provided on the intermediate layer 4.

Various materials can be used for forming the substrate

2 if they have insulation properties . Examples of such materials include various glass materials such as silica dioxide, silicon nitride, various resin materials such as polyethylene terephthalate, polyethylene naphthalete, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethylmethacrylate, polycarbonate, polyarylate, and various dielectric materials (so-called "low-K materials) , and the like .

Further, the substrate 2 may be removed (separated) after the substrate for electronic devices 1 has been formed, or the substrate 2 may be used together with the substrate for electronic devices 1.

In the substrate for electronic devices 1 , the electrode

3 contains metal atoms and has a function of injecting carriers (holes or electrons) into the intermediate layer 4.

Various materials can be used for forming the electrode 3 if they contain metal atoms . Examples of such materials include metal oxides such as indium tin oxide (ITO), indium oxide (10), tin oxide (SnO₂), antimon tin oxide (ATO), indium zinc oxide (IZO) , zinc oxide (ZnO) , metallic materials such as Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Sb, Y, Yb, Ag, Cu, Al, Cs, Rb, Cr, Mo, Ta, Au, Pt, Ni, and alloys containing two or more of them.

In this regard, it is to be noted that that the electrode may be used as an anode, a cathode or an alternate current electrode by selecting these materials appropriately.

The intermediate layer 4 is provided between the electrode 3 and the organic semiconductor layer 5 so as to be in contact with both the electrode 3 and the organic semiconductor layer 5. The intermediate layer 4 has a function of injecting carriers, which have been injected from the electrode 3, into the organic semiconductor layer 5 again, that is, has a function of transferring the carrier from the electrode 3 to the organic semiconductor layer 5 through the intermediate layer 4.

As described above, the intermediate layer 4 is constituted of a material containing as its major component a ligand having ligand atoms and a conjugated structure.

Hereinbelow, a description will be made with regard to this ligand.

The total number of carbon atoms of the ligand is preferably 40 or less, and more preferably in the range of about 4 to 20. This makes it possible to prevent the molecule structure of the ligand from becoming large over a necessary size. As a result, it is possible to appropriately prevent a sterile hindrance between adjacent ligands from being enlarged when each ligand coordinates to a metal atom contained in a constituent material of the electrode 3. Consequently, it becomes possible to coordinate the ligands to the metal atoms effectively. This makes it possible to improve adhesion between the electrode and the intermediate layer 4 reliably to thereby reduce the difference between the carrier transport abilities of the electrode 3 and the intermediate layer 4 appropriately.

Further, in the case where the number of carbon atoms of each of the ligands lies within the above-mentioned range, each ligand can be coordinated to the metal atom in a state that an appropriate interval (gap) exists between the adjacent ligands . As a result, the organic semiconductor material is allowed to enter the gaps when the organic semiconductor layer 5 is formed on the intermediate layer 4. This makes it possible to increase a contacting area of the conjugated structures contained respectively in the organic semiconductor material and the ligands , so that transfer of carriers can be carried out smoothly between the intermediate layer 4 and the organic semiconductor layer 5.

Such ligand is classified into a unidentate ligand which has one ligand atom that coordinates to a metal atom, and a multidentate ligand which has two or more ligand atoms that coordinate to a metal atom.

In the case where a unidentate ligand is used as the ligand, such a ligand has a relatively low-molecular weight, thus enabling to prevent appropriately a sterile hindrance between the adjacent unidentate ligands from being enlarged. As a result, the ligands can coordinate to the metal atoms of the electrode 3 effectively.

Examples of such a unidentate ligand having one ligand atom include, but not limited thereto, pyridine, quinoline, isoquinoline, thiophene, benzo[b] thiophene, benzo[c]thiophene, furane, benzofurane, phenol, triphenylphosphine, triphenylamine , and tributylphosphine, and the like .

Examples of a unidentate ligand having two or more ligand atoms (coordination sites), but it coordinates to a metal atom through its one ligand atom, include pyridazine, pyrimidine, triazine, quinazoline, quinoxaline, cinnoline, phthalazine, oxazole, isooxazole, thiazole, isothiazole, and the like. Further, in the unidentate ligand, the ligand atom(s) my exist at any sites, but it is preferred that the ligand atom(s) are contained in a conjugated structure . This makes it possible to incorporate carriers which have been injected from the electrode 3 through the metal atoms to which the ligand atom(s) coordinate into the conjugated structures appropriately and smoothly. As a result, the carriers can also be injected into the organic semiconductor layer 5 having the conjugated structures appropriately and smoothly.

I the unidentate ligands mentioned above, examples of an unidentate ligand having the above-described structure and having one ligand atom include pyridine, quinoline, isoquinoline, thiophene, benzo[b] thiophene, benzo[c] thiophene, furane, benzofurane, isobenzofurane, and the like. Further, examples of an unidentate ligand having the above-described structure and having two or more ligand atoms but one ligand atom coordinates to one metal atom include include pyridazine, pyrimidine, triazine, quinazoline, quinoxaline, cinnoline, phthalazine, oxazole, isooxazole, thiazole, isothiazole, and the like.

Further, in the case where a multidentate ligand is used as the ligand, two or more ligand atoms can coordinate to one metal atom so that the bonding of the ligands in the intermediate layer 4 and the metal atoms can be made stably as compared to the case where one ligand atom is coordinated. As a result, it is possible to reliably transfer the carriers which have been injected through the metal atoms to the side of the conjugated structures .

Examples of such a multidentate ligand include, but not limited thereto, compounds represented by the following general formulas (1) to (10):

wherein in each of the general formulas two substituents A⁰S are the same or different and each independently represents a hydrogen atom, a chlorine atom, a carboxy group, a hydroxy group, or a straight-chain alkyl group having 1 to 10 carbon atoms, a substituent X⁰ represents a nitrogen atom, an oxygen atom, a sulfur atom, or a selenium atom, a substituent Y⁰ represents a hydroxy group, a mercapto group, an amino group or a carboxy group, and a substituent Z⁰ represents a hydrogen atom, a chlorine atom, or a straight-chain alkyl group having 1 to 10 carbon atoms.

Each of these multidentate ligands has a structure in which two to four carbon atoms exist between the ligand atoms. By forming the multidentate ligands so as to have such structures, it is possible to coordinate two or more ligand atoms to the metal atom reliably.

Further, in the multidentate ligands, the ligand atoms may be positioned inside or outside of the conjugated structure, and these multidentate ligands can be classified, but not limited thereto, into the following three types according to the positions of the ligand atoms .

(1) all of the ligand atoms exist outside the conjugated structure, (2) a part of the ligand atoms is contained inside the conjugated structure, and (3) all of the ligand atoms are contained inside the conjugated structure.

By selecting the type (1) where all of the ligand atoms exist outside the conjugated structure, the ligand atoms are contained in substituents existing outside the conjugated structure. As a result, the ligand atoms can be rotated (moved) about the atoms in the conjugated structure to which the substituents are bonded, respectively. Therefore, the size of the distance between the ligand atoms can be adjusted so as to meet with the size of the atomic radium of the metal atom so that the two ore more ligand atoms can be coordinated to the metal atom reliably. As a multidentate ligand having such a structure, the compound represented by the above-mentioned general formula (1) can be preferably selected, for example. This makes it possible to exhibit the effect obtained by the structure of the type (1) effectively.

In this regard, it is to be noted that in the compound represented by the above-mentioned general formula (10) , it is preferred that the substituent Z⁰ is bonded to 3 or 4 position of the benzene ring. By selecting such a positional relationship between the substituent Z⁰ and each of the substituents Y⁰, it is possible to coordinate the ligand atoms contained in the substituents Y⁰ to the metal atom reliably.

The kind of the substituent Z⁰ is appropriately selected by taking solubility of the compound to a solvent used when preparing an intermediation layer formation material (which will be described later) into account.

When a straight-chain alkyl group having 1 to 10 carbon atoms is selected as the substituent Z⁰, the number of the carbon atoms is preferably in the range of 2 to 8 , and more preferably in the range of 4 to 6. In this connection, from the viewpoint of improving adhesion between the electrode 3 and the intermediate layer 4 , it is preferred that the ligands are coordinated to the electrode 3 in close contact thereto. On the other hand, however, from the viewpoint of preventing the interaction between the conjugated structures from being increased, it is preferred that the ligands are coordinated far away from the electrode 3 to a certain degree. Therefore, by selecting a substituent Z⁰ having carbon atoms within the above range, it is possible to coordinate the ligand atoms to the metal atom reliably while preventing appropriately the adjacent conjugated structures from being closely approached. As a result, it is possible to reliably transfer carriers that have been injected into the conjugated structures through the ligand atoms in the thickness direction of the intermediate layer, that is, toward the organic semiconductor layer 5, without causing the carriers to be moved in the intermediate layer 4 in the surface direction thereof .

Further, by selecting the type (2) where a part of the ligand atoms exists outside the conjugated structure, it is possible to transfer carriers which have been injected from the electrode 3 through the metal atoms to the side of theconjugated structures appropriately and smoothly at the ligand atom(s) contained in the conjugated structure. As a result, the carriers can be injected into the organic semiconductor layer 5 through the conjugated structures appropriately and smoothly.

As a multidentate ligand having such a structure, the compound represented by any one of the above-mentioned general formulas (3) to (9) can be preferably selected, for example. This makes it possible to exhibit the effect obtained by the structure of the type (2) effectively.

In the compounds represented by the above-mentioned general formulas ( 3 ) to ( 9 ) , it is preferred that the substituent Z⁰ is bonded to a 3 or 4 position of the benzene ring. In the case of the compound represented by the general formula (3), this makes it possible to coordinate the ligand atom and the nitrogen atom to the metal atom reliably. Further, in the case of the compound represented by the above-mentioned general formula (8) or (9), it is possible to coordinate the ligand atom contained in the substituent Y⁰ and the ligand atom X⁰ to the metal atom reliably.

Further, when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas (4) and (5), it is preferred that the substituent Z⁰ is bonded to a heteroaromatic ring at its 3 or 4 position. In the case of the compound represented by the above-mentioned general formula (4), this makes it possible to coordinate the ligand atom contained in the substituent Y⁰ and the ligand atom X⁰ to the metal atom reliably. Further, in the case of the compound represented by the above-mentioned general formula ( 5 ) , it is possible to coordinate the ligand atom, contained in the substituent Y⁰ and the nitrogen atom to the metal atom reliably.

Furthermore, when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas ( 6 ) and ( 7 ) , it is preferred that the substituent Z⁰ is bonded to a benzene ring at its 4 or 5 position. This makes it possible to coordinate the ligand atom contained in the substituent Y⁰ and the ligand atom X⁰ to the metal atom reliably.

In this regard, it is to be noted that the kind of the substituent Z⁰ in the compounds represented by the above-mentioned general formulas (3) to (9) is appropriately selected by taking solubility of the compound to a solvent to be used when preparing an intermediation layer formation material (which will be described later) into account.

Furthermore, when a straight-chain alkyl group having 1 to 10 carbon atoms is selected as the substituent Z⁰, the number of carbon atoms contained therein is preferably in the range of 2 to 8, and more preferably in the range of 4 to 6. In this connection, from the viewpoint of improving adhesion between the electrode 3 and the intermediate layer 4 , it is preferred that the ligands are coordinated to the electrode 3 in close contact thereto. On the other hand, however, from the viewpoint of preventing the interaction between the conjugated structures from being increased, it is preferred that the ligands are coordinated far away from the electrode 3 to a certain degree. Therefore, by selecting a substituent Z⁰ having carbon atoms within the above range, it is possible to coordinate the ligand atoms to the metal atom reliably while preventing appropriately the adjacent conjugated structures from being closely approached. As a result, it is possible to reliably transfer carriers that have been injected into the conjugated structures through the ligand atoms in the thickness direction, that is, toward the organic semiconductor layer 5, without causing the carriers to be moved in the intermediate layer 4 in the surface direction thereof.

Moreover, by selecting the type (3) where all of the ligand atoms exist inside the conjugated structure, it is possible to exhibit the effect obtained by containing the ligand atoms in the conjugated structure more appropriately. Namely, it is possible to exhibit the effect explained with reference to the type (2) more reliably.

As a multidentate ligand having such a structure, the compounds represented by the above-mentioned general formulas ( 1 ) and ( 2 ) can be preferably selected, for example . This makes it possible to exhibit the effect obtained by the structure of the type (3) effectively.

In this regard, it is to noted that in each of the compounds represented by the above-mentioned general formulas (1) and (2) , it is preferred that the substituent A⁰S is bonded to a pyridine ring at its 3 or 4-position. This makes it possible to coordinate two nitrogen atoms (ligand atoms) to the metal atom reliably.

Further, the kind of the substituent A⁰ in each of the compounds represented by the above-mentioned general formulas (1) and (2) is appropriately selected by taking solubility of the compound to a solvent used when preparing an intermediation layer formation material (which will be described later) into account .

Furthermore, when a straight-chain alkyl group having 1 to 10 carbon atoms is selected as the substituent A⁰, the number of carbon atoms contained therein is preferably in the range of 2 to 8 , and more preferably in the range of 4 to 6. In this connection, from the viewpoint of improving adhesion between the electrode 3 and the intermediate layer 4,, it is preferred that the ligands are coordinated to the electrode 3 in close contact thereto. On the other hand, however, from the viewpoint of preventing the interaction between the conjugated structures from being increased, it is preferred that the ligands are coordinated far away from the electrode 3 to a certain degree . Therefore, by selecting a substituent A⁰ having carbon atoms within the above range, it is possible to coordinate the ligand atoms to the metal atom reliably while preventing appropriately the adjacent conjugated structures from being closely approached. As a result, it is possible to reliably transfer carriers that have been injected into the conjugated structures through the ligand atoms in the thickness direction, that is, toward the organic semiconductor layer 5 , without causing the carriers to be moved in the intermediate layer 4 in the surface direction thereof.

As described above, various types of compounds can be mentioned as the ligand. However, in general, the organic semiconductor material described below has a structure in which a lot of conjugated structures such as aromatic rings e.g. benzene rings , pyridine rings , thiophene rings and the like are contained. Therefore, it is preferred the conjugated structure of the ligand also has such a structure. This makes it possible for the conjugated structure of the ligand and a part of the organic semiconductor material have the same structure, thereby enabling the compatibility therebetween to be improved further. As a result, transfer of carriers between the intermediate layer 4 and the organic semiconductor layer 5 can be carried out more smoothly. Further, since a structure having many conjugated bonds has an excellent carrier transport ability, there is also an advantage that a carrier transport ability in the intermediate layer 4 can be improved.

Taking the above factors into account, it is preferred that the ligand of the present invention should be a multidentate ligand and the conjugated structure contains many conjugated bonds, that is, it is preferred to select any one of the compounds represented by the above-mentioned general formulas (1) to (10).

Further, since these ligands can be coordinated to metal atoms contained in the various constituent materials of the electrode 3, a more preferable compound can be selected according to the properties of a metal atom to be coordinated such as the size of the atomic radius , the level of the ionization potential, and the like.

Specifically, in the case where ITO, IO or IZO is selected as a constituent material of the electrode 3 and indium is contained as the metal atom, a ligand having a conjugated structure in which two or more aromatic rings are contained and at least one pyridine skeleton is also contained, that is, any one of the compounds represented by the above-mentioned general formulas (1) to (3) is selected.

Further, in the case where a material containing Cu is selected as a constituent material of the electrode 3, the compound represented by any one of the above-mentioned general formulas (1) or (3) is selected as the ligand. Furthermore, in the case where a material containing Au is selected as a constituent material of the electrode 3, the compound represented by the above-mentioned general formula (1) is selected as the ligand. Moreover, in the case where a material containing Ca or Li is selected as a constituent material of the electrode 3 , the compound represented by the above-mentioned general formula (3) is selected as the ligand.

The average thickness of the intermediate layer 4 may be changed slightly depending on the kind of ligand to be selected, but it is preferably 10 nm or less, and more preferably in the range of about 0.5 to 2 nm. By setting the thickness of the intermediate layer 4 within the range, it is, possible to form a layer in which one ligand exists in its thickness direction, that is, a monomolecular film of the ligands . As a result, it is possible to exhibit the result obtained by coordinating the ligand to the metal element more conspicuously.

The organic semiconductor layer 5 is mainly comprised of an organic semiconductor material having a conjugated structure, and according to the functions of the organic semiconductor layer 5, appropriate organic semiconductor materials are selected.

Examples of such organic semiconductor materials include an organic semiconductor material having a function of transporting holes (hole transport material), an organic semiconductor material having a function of transporting electrons (electron transport materials), and an organic semiconductor material having a function of emitting light holes (light emitting material), and the like.

In more details, examples of such an hole transport material include: thiophene/styrenesulfonic acid-based compounds such as 3,4-ethylenedioxythiophene/styrenesulfonic acid; arylcycloalkane-based compounds such as 1, l-bis(4-di-para-triaminophenyl)cyclohexane and

1,1' -bis ( 4-di-para-tolylaminophenyl) -4-phenyl-cyclohexane; arylamine-based compounds such as 4,4' ,4' ' -trimethyltriphenylamine,

N, N, N' ,N'-tetraphenyl-1,1 '-biphenyl-4, 4 ' -diamine, N,N' -diphenyl-N,N' -bis ( 3-methylphenyl) -1 , 1 ' -biphenyl-4 , 4 ' -d iamine (TPDl) ,

N,N' -diphenyl-N,N' -bis ( 4-methoxyphenyl) -1,1' -biphenyl-4 , 4 ' - diamine (TPD2) ,

N,N,N' ,N' -tetrakis ( 4-methoxyphenyl ) -1 , 1 ' -biphenyl-4,4'-diam ine(TPD3), _N,N' -di( 1-naphthyl) -N,N' -diphenyl-1, 1 ' -biphenyl-4 , 4 ' -diamin e(α-NPD), and TPTE; phenylenediamine-based compounds such as N,N,N' ,N' -tetraphenyl-para-phenylenediamine, N,N,N' ,N' -tetra(para-tolyl)-para-phenylenediamine, and N,N,N' ,N' -tetra(meta-tolyl) -meta-phenylenediamine(PDA) ; carbazole-based compounds such as carbazole, N-isopropylcarbazole, and N-phenylcarbazole; stilbene-based compounds such as stilbene, and 4-di-para-tolylaminostilbene; oxazole-based compounds such as O_xZ; triphenylmethane-based compounds such as triphenylmethane , and m-MTDATA; pyrazoline-based compounds such as 1-phenyl-3- (para-dimethylaminophenyl)pyrazoline ; benzine(cyclohexadiene) -based compounds; triazole-based compounds such as triazole; imidazole-based compounds such as imidazole; oxadiazole-based compounds such as 1,3,4-oxadiazole, and

2 , 5-di( 4-dimethylaminophenyl) -1 , 3 , 4-oxadiazole; anthracene-based compounds such as anthracene, and 9- ( 4-diethylaminostyryl) anthracene; fluorenone-based compounds such as fluorenone, 2, 4, 7-trinitro-9-fluorenone, and

2, 7-bis(2-hydroxy-3-(2-chlorophenylcarbamoyl) -1-naphthylazo ) fluorenone; aniline-based compounds such as polyaniline; silane-based compounds; thiophene-based compounds such as polythiophene, and poly(thiophenevinylene) ; pyrrole-based compounds , such as poly(2, 2 ' -thienylpyrrole) , and 1 , 4-dithioketo-3 , 6-diphenyl-pyrrolo- ( 3 , 4-c)pyrrolopyrrole; florene-based compounds such as florene; porphyrin-based compounds such as porphyrin, and metal tetraphenylporphyrin; quinacridon-based compounds such as quinacridon; metallic or non-metallic phthalocyanine-based compounds such as phthalocyanine , copper phthalocyanine , tetra(t-butyl) copper phthalocyanine, and iron phthalocyanine; metallic or non-metallic naphthalocyanine-based compounds such as copper naphthalocyanine, vanadyl naphthalocyanine , and monochloro gallium naphthalocyanine; and benzidine-based compounds such as N,N' -di(naphthalene-l-yl)-N,N' -diphenyl-benzidine and N,N,N' ,N' -tetraphenylbenzidine. Polymers formed from these compounds also have a higher hole transport ability.

Further, examples of the electron transport material include: benzene-based compounds (starburst-based compounds) such as

1,3,5-tris [ ( 3-phenyl-6-tri-fluoromethyl)quinoxaline-2-yl] benzene (TPQl), and

1,3,5-tris [ {3- ( 4-t-butylphenyl) -6-trisfluoromethyl}quinoxal ine-2-yl]benzene (TPQ2); naphthalene-based compounds such as naphthalene; phenanthrene-based compounds such as phenanthrene; chrysene-based compounds such as chrysene; perylene-based compounds such as perylene; anthracene-based compounds such as anthracene; pyrene-based compounds such as pyrene; acridine-based compounds such as acridine; stilbene-based compounds such as stilbene; thiophene-based compounds such as BBOT; butadiene-based compounds such as butadiene; coumarin-based compounds such as coumarin; quinoline-based compounds such as quinoline; bistyryl-based compounds such as bistyryl; pyrazine-based compounds such as pyrazine and distyrylpyrazine; quinoxaline-based compounds such as quinoxaline; benzoquinone-based compounds such as benzoquinone, and 2, 5-diphenyl-para-benzoquinone; naphthoquinone-based compounds such as naphthoquinone; anthraquinone-based compounds such as anthraquinone; oxadiazole-based compounds such as oxadiazole, 2-(4-biphenylyl) -5- (4-t-butylphenyl) -1 , 3 , 4-oxadiazole (PBD) , BMD, BND, BDD, and BAPD; triazole-based compounds such as triazole, and 3, 4 , 5-triphenyl-l , 2, 4-triazole; oxazole-based compounds; anthrone-based compounds such as anthrone; fluorenone-based compounds such as fluorenone, and 1 , 3 , 8-trinitro-fluorenone (TNF); diphenoquinone-based compounds such as diphenoquinone, and MBDQ; stilbenequinone-based compounds such as stilbenequinone, and MBSQ; anthraquinodimethane-based . compounds; thiopyran dioxide-based compounds; fluorenylidenemethane-based compounds; diphenyldicyanoethylene-base.d compounds; florene-based compounds such as florene; metallic or non-metallic phthalocyanine-based compounds such as phthalocyanine , copper phthalocyanine, and iron phthalocyanine ; and various metal complexes such as 8-hydroxyquinoline aluminum (AIq₃) , and complexes having benzooxazole or benzothiazole as a ligand. These compounds may be used singly or in combination of two or more of them.

Furthremo, As light emitting materials , there are various low molecular type light emitting materials and various high molecular type light emitting materials as mentioned hereinbelow, and at least one of these materials can be used.

In this regard, it is to be noted that when a low molecular type light emitting material is used, a dense light emitting layer (organic semiconductor layer 5) can be obtained, thus enabling a light emitting efficiency of the light emitting layer to be improved. On the other hand, when a high molecular type light emitting material is used, it is possible to form a light emitting layer easily using any one of various application methods such as an ink-jet printing method and the like since such a material can be dissolved into a , solvent relatively easily. Further, when the low molecular type light emitting material is used in combination with the high molecular type light emitting material, it is possible to obtain a synergistic effect of both the low molecular type light emitting material and the high molecular type light emitting material. That is to say, it is possible to obtain an effect that a dense light emitting layer having a high luminescent efficiency can be easily formed by using various application methods such as an ink-jet printing method and the like.

Examples of such a low molecular type light emitting material include: benzene-based . compounds such as distyrylbenzene (DSB), and diaminodistyrylbenzene (DADSB); naphthalene-based compounds such as naphthalene and Nile red; phenanthrene-based compounds such as phenanthrene ; chrysene-based compounds such as chrysene and 6-nitrochrysene; perylene-based compounds such as perylene and N,N' -bis ( 2 , 5-di-t-butylphenyl) -3,4,9, 10-perylene-di-carboxy imide (BPPC); coronene-based compounds such as coronene; anthracene-based compounds such as anthracene and bisstyrylanthracene; pyrene-based compounds such as pyrene; pyran-based compounds such as

4- (di-cyanomethylene) -2-methyl-6- (para-dimethylaminostyryl) -4H-pyran (DCM); acridine-based compounds such as acridine; stilbene-based compounds such as stilbene; thiophene-based compounds such as 2, 5-dibenzooxazolethiophene; benzooxazole-based compounds such as benzooxazole; benzoimidazole-based compounds such as benzoimidazole; benzothiazole-based compounds such as 2,2'- (para-phenylenedivinylene) -bisbenzothiazole; butadiene-based compounds such as bistyryl (1,4-diphenyl-1,3-butadiene) and tetraphenylbutadiene; naphthalimide-based compounds such as naphthalimide; coumarin-based compounds such as coumarin; perynone-based compounds such as perynone; oxadiazole-based compounds such as oxadiazole; aldazine-based compounds; cyclopentadiene-based compounds such as 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP) ; quinacridone-based compounds such as quinacridone and quinacridone red; pyridine-based compounds such as pyrrolopyridine and thiadiazolopyridine; spiro compounds such as 2, 2' , 7, 7 ' -tetraphenyl-9 , 9 ' -spirobifluorene; metallic or non-metallic phthalocyanine-based compounds such as phthalocyanine (H₂Pc) and copper phthalocyanine; florene-based compounds such as florene; and various metallic complexes such as 8-hydroxyquinoline aluminum (AIq₃), tris ( 4-methyl-8-quinolinolate) aluminum( III ) (Almq₃) , (8-hydroxyquinoline) zinc (Znq₂), ( 1 , 10-phenanthroline) -tris- (4 , 4 , 4-trifluoro-1- (2-thienyl) -b utane-l,3-dionate) europium(III) (Eu(TTA) ₃(phen) ), fac-tris(2-phenylpyridine) iridium (Ir(ppy)₃), and (2,3,7,8,12,13,17, 18-octaethyl-21H, 23H-porphin) platinum(II) , and the like.

Further, examples of such a high molecular type light emitting material include polyacetylene-based compounds such as trans-type polyacetylene , cis-type polyacetylene, poly(di-phenylacetylene) (PDPA), and poly(alkyl, phenylacetylene) (PAPA); polyparaphenylenevinylene-based compounds such as poly(para-phenylenevinylene) (PPV), poly(2 , 5-dialkoxy-para-phenylenevinylene) (RO-PPV) , cyano-substituted-poly(para-phenylenevinylene) (CN-PPV) , poly(2-dimethyloctylsilyl-para-phenylenevinylene) (DMOS-PPV), and poly( 2-methoxy-5- ( 2 ' -ethylhexoxy) -para-phenylenevinylene)_ (MEH-PPV) ; polythiophene-based compounds such as poly(3-alkylthiophene) (PAT), and poly(oxypropylene) triol (POPT); polyfluorene-based compounds such as poly(9,9-dialkylfluorene) (PDAF) , α, ω-bis [N,N ' -di(methylphenyl)aminophenyl] -poly[9,9-bis ( 2- ethylhexyl)fluorene-2,7-diyl] (PF2/6am4) , poly( 9 , 9-dioσtyl-2 , 7-divinylenefluorenyl) -alt-co (anthracene -9,10-diyl); polyparaphenylene-based compounds such as poly(para-phenylene) (PPP) , and poly(l, 5-dialkoxy-para-phenylene) (RO-PPP) ; polycarbazole-based compounds such as poly(N-vinylcarbazole) (PVK); and polysilane-based compounds such as poly(methylphenylsilane) (PMPS), poly(naphthylphenylsilane) (PNPS) , and poly(biphenylylphenylsilane) (PBPS) , and the like.

Further, it is preferred that the organic semiconductor material is comprised of a polymer obtained by polymerizing monomers each having polymerizable groups at their polymerizable groups . By forming the organic semiconductor material in this way, the polymer is formed so that it interweaves with the conjugated structures of. the intermediate layer 4 when the monomers are polymerized. This makes it possible to improve adhesion between the intermediate layer 4 and the organic semiconductor layer 5.

As such a monomer, it is possible to use a monomer obtained by introducing polymerizable groups to any one of the low molecular type organic semiconductor materials described above .

Specifically, a compound represented by the following general formula (Al) or (A2) can be mentioned. By using such a compound, the effect obtained by polymerizing monomers can be exhibited reliably.

wherein two R¹S are the same or different and each independently represents a straight-chain alkyl group having 2 to 8 carbon atoms , four R²S are the same or different and each independently represents a hydrogen atom, a methyl group or an ethyl group, Y represents a group containing at least one substituted or unsubstituted aromatic hydrocarbon ring or substituted or unsubstituted heterocycle, and two X¹S are the same kind of substituent represented by any one of the following general formulas (Bl) to (B3), in which the number of carbon atoms of the two X¹S are the same as or different from to each other; or

wherein eight Rs are the same or different and each independently represents a hydrogen atom, a methyl group, or an ethyl group, Y represents a group containing at least one substituted or unsubstituted aromatic hydrocarbon ring or substituted or unsubstituted heterocycle, and X², X³, X⁴ and X^s are the same kind of substituent which is represented by any one of the following general formulas (Bl) to (B3), in which the number of carbon atoms of X², X³, X⁴ and X⁵ are the same as or different from to each other.

wherein n¹ is an integer of 2 to 8, n² is an integer of 3 to 8, m is an integer of 0 to 3, Z¹ represents a hydrogen atom or a methyl group, and Z² represents a hydrogen atom, a methyl group or an ethyl group. Hereinbelow, a description will be made with regard to the features of these polymers .

Each of the polymers is obtained by a polymerization reaction of the compound (Al) or the compound (A2) (which is a diphenylamine derivative) through its polymerizable groups, that is, a polymer in which main skeletons (a diphenylamine skeleton) which is a portion of each compound other than its polymerizable groups are linked via a chemical structure formed by the reaction between the polymerizable groups thereof (hereinafter, this chemical structure is referred to as "a link structure" ) .

First, a description will be made with regard to a polymer obtained from the compound (Al).

In a polymer obtained by a polymerization reaction of the compound (Al) via its substituents (that is, a substituent of a compound (Al) and a substituent of a compound (Al)), the polymer has a structure in which the main skeletons of the compounds are repeatedly linked via the link structure, that is, a structure in which the main skeletons repeatedly exist at a predetermined interval. Therefore, the interaction between the adjacent main skeletons decreases.

Further, each main skeleton has a conjugated chemical structure, and a unique spread of the electron cloud thereof contributes to smooth transportation of carriers (holes or electrons) in the polymer.

For this reason, the polymer exhibits a high carrier transport ability. Therefore, an organic semiconductor layer 5 obtained by using such a polymer as its main material also has a high carrier transport ability. In this regard, it is to be noted that if the interval between the main skeletons in the polymer is too small, interaction between the adjacent main skeletons tends to be strong. On the other hand, if the interval between the main skeletons in the polymer is too large, it becomes difficult to transfer carriers between the main skeletons , causing the carrier transport ability of the polymer to be impaired.

Therefore, it is preferred that the structure of the substituent X¹ is determined in view of these facts mentioned above. Specifically, in the case where a substituent represented by the above general formula (Bl) or (B2) is selected as the substituent X¹, it is preferred that the substituent X¹ has a straight-chain carbon to carbon link in which n¹ is 2 to 8, in particular 3 to 6. Further, in the case where a substituent represented by the above general formula (B3) is selected as the substituent X¹, it is preferred that the substituent X¹ has a straight-chain carbon to carbon link in which n² is 3 to 8 and m is 0 to 3 , in particular n² is 4 to 6 and m is 1 or 2.

By satisfying the above relation, it becomes possible for the adjacent main skeletons to exist at a suitable interval, thereby decreasing the interaction between the adjacent main skeletons in the polymer reliably. In addition, it is also possible to transfer carriers between the main skeletons more reliably so that the polymer can also have a high carrier transport ability.

In this connection, in the case where a substituent represented by the above general formula (Bl) or (B2) is selected as the substituent X¹, each substituent X¹ has a (meth)acryloyl group or an epoxy group as its end. Since each of the (meth)acryloyl group and the epoxy group has high reactivity and bonding stability, it is relatively easy to polymerize substituents X¹ directly to thereby form a polymer having a long chain length.

Further, the link structure obtained by polymerization reaction via the (meth)acryloyl groups has two double bonds (π bonds) including one existing between an oxygen atom and a carbon atom and another existing between carbon atoms . Therefore, even in the case where the interval between the main skeletons becomes relatively long, transfer of carriers between the main skeletons can be carried out reliably through the two π bonds (that is, conjugated bonds).

Furthermore, since a straight-chain carbon to carbon link (i.e. , an alkylene group) exists between each of the two it bonds and each main skeleton, it is possible to prevent or suppress the interaction between the main skeletons from being enhanced.

Moreover, the link structure obtained by polymerization reaction of the epoxy groups has ether links (bonds) and a straight-chain carbon to carbon link (i.e., alkylene groups). In such a link structure having the above structure, transfer of electrons is suppressed. Therefore, even in the case where the interval between the adjacent main skeletons is relatively small, it is possible to prevent or suppress the interaction between the main skeletons from being enhanced.

In this connection, it is to be noted that if the link structure has a structure having many conjugated π bonds such as a benzene ring, interaction occurs between the adjacent main skeletons through such a structure, which cancels the effect obtained by allowing the adjacent main skeletons to exist at a suitable interval.

In this regard, however, in the case where a substituent represented by the general formula (B3) is selected as the substituent X¹, the substituent X¹ has a styrene derivative group formed by introducing a substituent Z to a styrene group as its functional group at one end thereof. Therefore, benzene rings exist in the link structure.

As a result, in the case where each of the benzene rings and each of the main skeletons having a conjugated chemical structure are too close to each other, that is, in the case where the benzene ring is linked to the main skeleton via an ether bond or in the case where the total of n² and m is two , interaction occurs between the adjacent main skeletons through the benzene rings .

However, in this polymer, the linkage between the main skeleton and the benzene ring is formed by n² and m the total of which is three or more, that is three or more methylene groups and an ether bond exist therebetween. This makes it possible to maintain the interval between the main skeleton and the benzene ring at a suitable condition. With this result, it is possible to prevent or suppress interaction from occurring between the adjacent main skeletons appropriately.

Further, the substituent Z² is a hydrogen atom, a methyl group or an ethyl group, wherein the substituent Z² is selected in accordance with the total of n² and m, that is the total number of methylene groups.

For example, in the case where the total number is small, a methyl group or an ethyl group is selected as the substituent Z². Since a methyl group and an ethyl group are an electron-releasing substituent, it is possible to bias electrons to the side of the main skeleton by selecting a methyl group or an ethyl group as the substituent Z². With this result, it is possible to prevent appropriately interaction from occurring between the adjacent main skeletons which are existed through the benzene rings .

Because of the reasons stated in the above, it is preferred that the two substituents X¹ have substantially the same number of carbon atoms , and more preferably exactly the same number of carbon atoms. In such a case, the interval between the adjacent main skeletons can be made substantially constant. Therefore, it is possible to prevent uneven distribution of the electron density from occurring in the polymer, thereby enabling a carrier transport ability of the polymer to be improved.

Furthermore, it is to be noted that the substituent X¹ may be bonded to the 2-, 3-, 4-, 5- or 6-position of the benzene ring, but preferably bonded to the 3-, 4- or 5-position. This makes it possible to more conspicuously exhibit the effect obtained by linking the adjacent main skeletons via the substituents X¹. Namely, it is possible for the adjacent main skeletons to exist at a suitable interval more reliably.

The substituent R¹ has a straight-chain alkyl group having 2 to 8 carbon atoms , preferably 3 to 6 carbon atoms . This makes it possible for adjacent polymers to exist at a suitable interval since the adjacent polymers are prevented from closely approaching to each other by steric hindrance of the substituents R¹. As a result, it becomes possible to reliably decrease the interaction between the adjacent main skeletons of different polymers in a layer to be formed, thereby enabling the layer to have a high carrier transport ability.

Preferably, the two substituents R¹ contain substantially the same number of carbon atoms , more preferably the same number of carbon atoms. This makes it possible for the adjacent polymers to exist at an interval of a certain distance in the layer. As a result , the density of polymers in the layer becomes uniform.

Further, the substituent R¹ may be bonded to any of the 2- to 6-position of a benzene ring, but preferably it is bonded to the 4-position. This makes it possible to exhibit the effect of introduction of the substituents R¹ more conspicuously. Namely, it is possible to reliably prevent the adjacent polymers from closely approaching to each other.

Furthermore, as described above, the substituent R² is a hydrogen atom, a methyl group, or an ethyl group, and the substituent R² is selected in accordance with the number of carbon in the substituent R¹. Specifically, when the number of carbon in the substituent R¹ is large, a hydrogen atom is selected as the substituent R², while when the number of carbon in the substituent R¹ is small, a methyl group or an ethyl group is selected as the substituent R².

In the compound (Al) , it is possible to change the carrier transport properties of the polymer to be formed by appropriately setting the chemical structure of a group (or a linking group) Y¹.

This is considered to result from the phenomenon that the energy level of the valence and conduction bands or the size of the band gap is changed in the polymer according to changes in the spread of the electron cloud (i.e., distribution of electrons) in the main skeleton which contributes to carrier transportation .

In the compound (Al), the group Y¹ contains at least one substituted or unsubstituted aromatic hydrocarbon ring or at least one substituted or unsubstituted heterocyclic ring. By selecting the kinds of the aromatic hydrocarbon ring and/or heterocyclic ring appropriately, it is possible to adjust carrier transport properties in a resultant polymer relatively easily.

For example, by selecting a structure constituted from an unsubstituted aromatic hydrocarbon ring as the group Y¹, it is possible to obtain a polymer which can exhibit a hole transport ability, and therefore such a polymer can be used as. the hole transport material.

In more details, as for the structure constituted from the unsubstituted aromatic hydrocarbon ring, those represented by the following chemical formulas (Cl) to (Cl7) can be mentioned.

In this case, it is preferred that the group Y¹ has 6 to 30 carbon atoms, more preferably 10 to 25 carbon atoms, and even more preferably 10 to 20, in total.

Further, in the group Yl, it is preferred that the number of aromatic hydrocarbon ring is 1 to 5 , more preferably 2 to 5, and even more preferably 2 or 3.

Taking the above-mentioned factors into account, in the compound (Al) a biphenylene group represented by the chemical formula (Cl) or its derivative is considered to be an especially preferable structure as the group Y¹.

By selecting such a group, the hole transport ability in the resultant polymer becomes excellent , and thus an organic semiconductor layer 5 to be formed from the polymer can also have a higher hole transport ability.

Next, by selecting a structure which contains at least one substituted or unsubstituted heterocyclic ring as the group Y¹, it is possible to control the carrier transport property of the resultant polymer relatively easily.

As for such a heterocyclic ring, it is preferred to select a heterocyclic ring which contains at least one heteroatom selected from among nitrogen, oxygen, sulfur, selenium, and tellurium. By selecting such a heterocyclic ring that contains such a kind of heteroatom, it is particularly easy to change the energy level of the valence and conduction bands or the size of the band gap of the polymer.

The heterocyclic ring may be either an aromatic heterocycle or a nonaromatic heterocycle, but an aromatic heterocycle is preferably used. By using an aromatic heterocycle, it is possible to properly prevent the electron density of the main skeleton with a conjugated chemical structure from being biased, that is, it is possible to properly prevent the localization of π electrons. As a result, the carrier transport ability of the polymer is prevented from being lowered.

The group Y¹ preferably contains 1 to 5 heterocyclic rings , more preferably 1 to 3 heterocyclic rings . In the case where the group Y contains 2 or more heterocyclic rings, these rings are the same or different . By allowing the group Y to have such a number of heterocyclic rings, it is possible to sufficiently change the energy level of the valence and conduction bands or the size of the band gap of the polymer.

The group Y¹ preferably has 2 to 75 carbon atoms, more preferably 2 to 50 carbon atoms, in total. If the group Y¹ has too many carbon atoms in total, the solubility of the compound represented by the general formula (Al) in a solvent tends to be lowered depending on the kind of substituent X¹.

By setting a total number of carbon atoms contained in the group Y¹ to a value within the above range, it is possible to maintain the planarity of the main skeleton. As a result, the carrier transport ability of the polymer is reliably prevented from being impaired.

Taking these factors into account, as a structure

10 11

12 1

(D 1 5 )

(D 1 4)

(D 1 6 )

(D 1 7 )

wherein in these chemical formulas Q¹S are the same or different and. each independently represents N-T¹, S, O, Se, or Te (where T¹ represents H, CH₃, or Ph), Q²S are the same or different and each independently represents S or O, and Q³S are the same or different and each independently represents N-T³, S, 0, Se, or Te (where T³ represents H, CH₃, C₂H₅ or Ph).

Furthermore, by selecting . chemical structures constituted from substituted or unsubstituted aromatic hydrocarbon ring and substituted or unsubstituted heterocyclic ring as the group (bonding group) Y¹, the synergistic effect resulted from the respective effects described above can be obtained.

In this regard, it is particularly preferred that such a group Y¹ contains aromatic hydrocarbon rings respectively bonded to each of Ns in the compound (A) and a heterocyclic ring existed between the aromatic hydrocarbon rings . This makes it possible to reliably prevent electron density from being biased in a resultant polymer. As a result, a carrier transport ability of the polymer can be made constant .

Taking these factors into account, as a structure constituted from the unsubstituted heterocyclic rings and the heterocyclic ring, such structures as represented by any one of the following chemical formulas (El) to (E3) are considered to be preferable structures .

wherein in these chemical formulas Q¹S are the same or different and each independently represents N-T¹, S, O, Se, or Te (where T¹ represents H, CH₃, or Ph) .

By appropriately determining the chemical structure of the group Y¹ as described above, a polymer obtained by selecting any one of the chemical formulas (D2), (D16), (El) and (E3) as the group Y can exhibit a high hole transport ability as compared to a polymer obtained by selecting the chemical formula (D17) and can exhibit an especially high hole transport ability as compared to a polymer obtained by selecting the chemical formula (D8) or (E2).

On the contrary, a polymer obtained by selecting any one of the chemical formulas (D8), (D17) and (E2) as the group Y¹ can exhibit a high electron transport ability as compared to a polymer obtained by the chemical formula (D2) or (D16). Further, a polymer obtained by selecting any one of the chemical formulas (D8), (D17) and (E2) as the group Y¹ can also exhibit an especially high electron transport ability as compared to a polymer obtained by selecting the chemical formula (D8) or (E2).

Furthermore, a polymer obtained by selecting either of the compound (Dl2) or the compound (Dl4) as the group Y¹ can be used as the light emitting material.

Further, the unsubstituted heterocyclic ring and/or the unsubstituted aromatic hydrocarbon ring contained in the group Y¹ may introduce a substituent so long as the planarity of the main skeleton is not greatly affected. Examples of such a substituent include an alkyl group having a relatively small number of carbon atoms such as a methyl group or an ethyl group or and a halogen group and the like.

Hereinbelow, a description will be made with regard to a polymer obtained from the compound (A2).

In this regard, it should be noted that the following description will be made by focusing the different points from the polymer obtained from the compound (Al), and explanations for the same or similar points are omitted.

The compound (A2) is the same as the compound (Al) excepting that the compound (Al) has two substituents X¹ and two substituents R¹ while the compound (A2) has four substituents X² to X⁵ and eight substituents R³.

As for each of the substituents X² to X⁵, a group having the same structure as that of the substituent X¹ is selected. In the compound (A2), since there are four substituents X² to X⁵, a two-dimensional network is easily to be formed.

In the compound (A2) , it is preferred that the substituent X² and the substituent X⁴ are identical with each other. Namely, it is preferred that the substituent X² and the substituent X⁴ have substantially the same number of carbon atoms and more preferably exactly the same number of carbon atoms . This makes it possible for the adjacent main skeletons of the compounds which are to be linked by the polymerization reaction at the respective substituents X² to X⁵ (that is, the substituent X² or the substituent X⁴) to make variation in their intervals small. Namely, it is possible to make variation in the intervals between the main skeletons small in a resultant polymer. As a result, it is possible to prevent the electron density from being biased in the resultant polymer effectively, thereby enabling a hole transport ability of the polymer to be improved.

In view of the above, it is also preferred that the substituent X³ and the substituent X^s are identical with each other. Namely, it is also preferred that the substituent X³ and the substituent X⁵ have substantially the same number of carbon atoms and more preferably exactly the same number of carbon atoms. This makes it possible to improve the above-described effect further, thereby enabling the carrier transport ability of the polymer to be further improved.

Further, it is also preferred that the substituent X², the substituent X³, the substituent X⁴ and the substituent X⁵ are identical with each other. Namely, it is also preferred that the substituent X², the substituent X³, the substituent X⁴ and the substituent X⁵ have substantially the same number of carbon atoms and more preferably exactly the same number of carbon atoms. This makes it possible to exhibit the above-described effect conspicuously. Further, in this case, since the length of each of the substituents X² to X⁵ which protrudes from the main skeleton is substantially the same (or exactly the same) with each other, it is possible to decrease a possibility that steric hindrance is caused by the substituents X² to X⁵. This makes it possible that polymerization reaction is carried out reliably between the substituents X² to X⁵, that is the polymer is produced reliably. With this result, it is possible to further improve the carrier transport ability of the polymer.

The substituent R³ is a hydrogen atom, a methyl group, or a ethyl group, and the substituent R³ can be selected according to the number of carbon atoms of the substituents X² to X⁵. For example, in the case where the number of carbon atoms of the substituents X² to X⁵ is large, a hydrogen atom is selected as the substituent R³, while in the case where the number of carbon atoms of the substituent R³ is small, a methyl group or an ethyl group is selected as the substituent R³.

In the meantime, as the substituent X¹ and the substituents X² to X⁵ (Hereinbelow, these substituents will be correctively referred to as "substituents X"), a chemical structure represented by the following general formula (B4) may be selected instead of the chemical structures represented by the general formulas (Bl) to (B3). In this case, in order to obtain a polymer by polymerization reaction at the substituents X, polycondensation reaction can be made in a state that phosgene represented by the chemical formula COCl₂ and/or its derivative is mediated between the substituents X to form a chemical structure represented by the following general formula (B5):

wherein each n¹ in these formulas independently represents an integer of 2 to 8, and these n¹s are the same or different . Such a polymer has a structure in which the main skeletons are repeatedly existed through the chemical structure represented by the general formula (B5), that is a chemical structure in which two straight-chain carbon to carbon bonds (alkylene groups) are linked through a carbonate linkage. Because of the existence of such a chemical structure, in the same manner as the case where each of the chemical structures represented by the general formulas (Bl) to (B3) is used, it is possible to allow the main skeletons to exist at a predetermined interval, thereby enabling interaction between the adjacent main skeletons to be decreased.

There is no specific limitation on the kind of phosgene and/or its derivative to be used if it is possible to form the chemical structure represented by the above-mentioned general formula (B5) by polycondensation reaction with the hydrokyl group at the end of each of the substituents X, but phosgene and/or its derivative which is mainly comprised of the compound represented by the following general formula (B6) are preferably used.

where two Z³S are the sama or different, and each independently represents an alkyl group, a phenyl group, or a benzyl group each having 1 to 6 carbon atoms .

When the substituents X¹ are allowed to make polycondensation reaction with phosgene and/or its derivative, a by-product material is produced. By using phosgene and/or the above-mentioned compound (B6) in the polycondensation reaction, it is possible to eliminate such a by-product material from an organic semiconductor layer 5 to be formed relatively easily. In this way, it is possible to prevent carriers from being captured, by the by-product material in the organic semiconductor layer 5 to be formed. As a result, it is possible to prevent appropriately a carrier transport ability of the organic semiconductor layer 5 from being decreased.

Now, a curing agent may be added to a polymer obtained from the compound (Al) or the compound (A2) as described above. Namely, polymerization reaction of the substituents X of the compound (Al) or the compound (A2) may be carried out via the curing agent .

Examples of such a curing agent include acryl-based curing agents, vinyl compounds such as divinylbenzene and epoxy-based curing agents, and the like.

In this connection, in the case where the chemical structure represented by any one of the above-mentioned general formulas (Bl) to (B3) is selected as the substituent X, it is particularly effective to make the polymerization reaction of the substituents X via the curing agent . This makes it possible to effectively prevent the interval between the main skeletons from becoming too small even in the case where a substituent having a relatively small number of carbon atoms , that is a substituent having a relatively short chain length is selected as the substituent X. As a result, since the interval between the main skeletons is maintained at a proper distance, it is possible to prevent reliably the interaction between the main skeletons from being increased.

In the case where the chemical structure represented by the above-mentioned general formula (Bl) is selected as the substituent X, it is preferable to use at least one acryl-based curing agent selected from the group comprising a polyester(meth)acrylate curing agent, and epoxy(meth)acrylate curing agent, and a polyurethane(meth)acrylate curing agent and the like. Examples of the polyester(meth)acrylate curing agent include the compounds represented by the following chemical formulas (Fl) to (F3).

Examples of the epoxy(meth)acrylate curing agent include the compounds represented by the following chemical formulas (F4) to (F8) .

Examples of the polyurethane(meth)acrylate curing agent include the compound represented by the following chemical formula (F9) .

(F9)

Note that in these general formulas , n³ is an integer equal to or smaller than 4,500, n⁴ is an integer of 1 to 3, and n⁵ is an integer of 0 to 1500. n⁶s are the same or different, and each independently represents an integer of 1 to 10. n⁷ is an integer of 1 to 40, and n⁸ is an integer of 1 to 100. R³S are the same or different, and each independently represents an alkylene group having carbon atoms of 1 to 10, and R⁴ represents an alkylene group having carbon atoms of 1 to 100. A¹S are the same or different, and each independently represents a hydrogen atom or a methyl group. A²S are the same or different, and each independently represents a group obtained by removing two isocyanate groups from a diisocyanate compound.

Further, in the case where the chemical structure represented by the general formula (B2) is selected, it is preferable to use at least one of the following epoxy-based curing agents as the curing agent. Namely, examples of such epoxy-based curing agents include a (meth) acrylic ester-based epoxy cross-linking agent, a bisphenol epoxy cross-linking agent, a glycidyl ester-based epoxy cross-linking agent, an alicyclic epoxy cross-linking agent , an urethane modified epoxy cross-linking agent, a silicon-containing epoxy cross-linking agent, a polyfunctional phenol-based epoxy cross-linking agent, and a glycidyl amine-based epoxy cross-linking agent.

As for such a (meth) acrylic ester-based epoxy cross-linking agent, the compound represented by the following general formula (Gl) can be mentioned.

As for a bisphenol epoxy cross-linking agent, the compounds represented by the following general formulas (G2) to (G6) can be mentioned.

As for such a glycidyl ester-based epoxy cross-linking agent, the compounds represented by the following general formulas (G7) and (G8) can be mentioned.

As for such an alicyclic epoxy cross-linking agent, the compounds represented by the following general formulas (G9) to (G12) can be mentioned.

As for such an urethane modified epoxy cross-linking agent, a silicon-containing epoxy cross-linking agent, the compound represented by the following general formula (G13) can be mentioned.

As for such a silicon-containing epoxy cross-linking agent, the compound represented by the following general formula (Gl4) can be mentioned.

As for such a polyfunctional phenol-based epoxy cross-linking agent , the compounds represented by the following general formulas (G15) to (G22) can be mentioned.

As for such a glycidyl amine-based epoxy cross-linking agent, the compounds represented by the following general formulas (G23) to (G25) can be mentioned.

Note that in these general formulas. A¹ represents a hydrogen atom or a methyl group. n⁶s are the same or different. and each independently represents an integer of 0 to 10, and n⁹s are the same or different, and each independently represents an integer of 1 to 20. n¹⁰ represents an integer of 1 to 30, and n¹¹ is an integer of 0 to 8. R³S are the same or different , and each independently represents an alkylene group having carbon atoms of 1 to 10, and R⁴ represents an alkylene group having carbon atoms of 1 to 100. A² represents a group obtained by removing two isocyanate groups from a diisocyanate compound, and A³s are the same or different, and each independently represents a group obtained by removing two isocyanate groups from a diisocyanate compound.

In the case where the chemical structure represented by the above-mentioned general formula (B3) is selected as the substituent X, it is preferable to use at least one vinyl compound such as polyethyleneglycoldi(meth)acrylate which is represented by the hollowing general formulas (Hl) and divinylbenzene .

wherein n¹² represents an integer of 5 to 15, and A¹S are the same or different, and each independently represents a hydrogen atom or a methyl group .

In the foregoing, a description was made with regard to the embodiment relating to the substrate for electronic devices 1 composed from a laminated body in which the intermediate layer 4 and the organic semiconductor layer 5 are laminated on the electrode 3 in this order. However, the present invention is not limited to such a structure, and may be formed into a structure in which an electrode is covered with an intermediate layer and then with an organic semiconductor layer. Such a substrate for electronic devices may be manufactured by the following processes, for instance.

[IA] Electrode formation step

First, a substrate 2 is prepared, and then an electrode

3 is formed on the substrate 2.

The anode 3 can be formed by, for example, chemical vapor deposition (CVD) such as a plasma CVD method, a thermal CVD method, and a laser CVD method, a vacuum deposition method, a sputtering method, a dry plating method such as an ion plating method, a wet plating method such as an electrolytic plating method, an immersion plating method, and an electroless plating method, a thermal spraying method, a sol-gel method, a MOD method, bonding of a metallic foil, or the like.

[2A] Intermediation layer formation step

Next , an intermediate layer 4 is formed on the thus formed electrode 3.

The intermediate layer 4 can be formed by, for example, an application method, a dip coating method, a vapor deposition method, a sputtering method, an electrolytic plating method, an immersion plating method, and an electroless plating, and the like .

Among these methods , the application method is preferably used for forming the intermediate layer 4. By using such an application method, it is possible to form an intermediate layer

4 that provides good adhesion with the electrode 3 relatively easily and reliably.

Hereinbelow, as a representative case, a description will be made with regard to the case where the application method is used for forming the intermediate layer 4.

[2A-1] First, the surface of the electrode 3 which has been formed in the preceding step [IA], that is, the metal atoms existing on the surface of the electrode 3 are halogenated with halogen such as fluorine, cholrine, bromine, iodine, and the like.

The halogenation can be carried out using various methods . For example, the halogenation can be carried out by heating the electrode 3 under a halogen atmosphere .

The condensation of the halogen in the atmosphere is preferably in the range of about 5 to 70 vol% , and more preferably in the range of about 10 to 30 vol%.

Further, the heating temperature is preferably in the range of about 80 to 200⁰C, and more preferably in the range of about 100 to 150⁰C.

Furthermore, the heating time is preferably in the range of about 10 to 120 minutes, and more preferably in the range of about 15 to 30 minutes.

By setting the various conditions into the above ranges , it is possible to halogenate the surface of the electrode 3 reliably.

[2A-2] Next, a liquid state intermediate layer formation material containing ligands is supplied onto the electrode 3.

Various methods can be used for supplying the intermediate layer formation material onto the electrode 3. Examples of such methods include an ink-jet method, a spin coating method, a liquid source misted chemical deposition method (LSMCD method) , a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire-bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, a micro contact printing method, and the like, and these methods can be employed singly or in combination of two ore more of them.

Further, the intermediate layer formation material may be in the form of a solution prepared by mixing the ligands into a solvent or a dispersion liquid prepared by mixing the ligands into a dispersion medium.

Examples of such a solvent or dispersion medium include: inorganic solvents such as nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, and ethylene carbonate; and various organic solvents such as ketone-based solvents e.g., methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), and cyclohexanone , alcohol-based solvents e.g., methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol (DEG), and glycerol, ether-based solvents e.g., diethyl ether, diisopropyl ether, 1,2-dimethoxy ethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), and diethylene glycol ethyl ether (Carbitol) , cellosolve-based solvents e.g., methyl cellosolve, ethyl cellosolve, and phenyl cellosolve, aliphatic hydrocarbon-based solvents e.g, hexane, pentane, heptane, and cyclohexane, aromatic hydrocarbon-based solvents e.g., toluene, xylene, and benzene, aromatic heterocyclic compound-based solvents e.g., pyridine, pyrazine, furan, pyrrole, thiophene, and methyl pyrrolidone, amide-based solvents e.g., N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA), halogen compound-based solvents e.g., dichloromethane, chloroform, and 1 , 2-dichloroethane, ester-based solvents e.g., ethyl acetate, methyl acetate, and ethyl formate, sulfur compound-based solvents e.g., dimethyl sulfoxide (DMSO) and sulfolane, nitrile-based solvents e.g., acetonitrile, propionitrile, and acrylonitrile, organic acid-based solvents e.g., formic acid, acetic acid, trichloroacetic acid, and trifluoroacetic acid, and mixed solvents containing them.

The condensation of the ligand in the intermediate layer formation material slightly varies depending on the kind of ligand to be used, but it preferably in the range of about 0.01 to 3.0 wt%, and more preferably in the range of about 0.5 to 1.0 wt%.

[2A-3] Next, the electrode 3 on which the intermediate layer formation material has been applied is heated. By heating the electrode 3, halogen is removed from the halogenated metal atoms , and ligands contained in the intermediate layer formation material are coordinated to the metal atoms .

The heating temperature is preferably in the range of about 80 to 250°C, and more preferably in the range of about 100 to 170°C.

The heating time is preferably in the range of about 30 to 180 minutes, and more preferably in the range of about 60 to 90 minutes.

The heating atmosphere is not limited to a specific condition, but an inert gas atmosphere such as nitrogen gas, argon gas, and helium gas is preferable.

By setting the various conditions into the above ranges, it is possible to coordinate the ligands to the metal atoms reliably.

[2A-4] Next, the solvent or dispersion medium contained in the intermediation layer formation material is removed.

In this way, the intermediate layer 4 constituted from the ligands which coordinate to the metal atoms, that is, the intermediate layer 4 which can exhibit excellent adhesion with the electrode 3, can be formed.

As a method for removing the solvent or dispersion medium, a method for heating, a method for drying under vacuum or reduced pressure, and a method for blowing inert gas can be employed. These methods can be employed alone or in combination of two or more of them. In the latter case, a combination of the method for heating and the method for drying under vacuum is particularly preferred.

In this way, it is possible to remove the solvent or dispersion medium from the intermediate layer formation material, while preventing the ligands from being uncoordinated from the metal atoms .

The heating temperature is preferably in the range of about 50 to 200⁰C, and more preferably in the range of 80 to 120°C.

Further, the heating time is preferably in the range of 10 to 120 minutes, and more preferably in the range of 30 to 60 minutes.

Furthermore, the pressure in the atmosphere is preferably 100 Pa or less, and more preferably 10 Pa or less.

By setting the various conditions into the above ranges, it is possible to remove the solvent or dispersion medium from the intermediate layer formation material.

[2A-5] Next, the thus formed intermediate layer is washed using a solvent such as ultra-pure water, diethyl ether, and heptane. In this way, it is possible to removed the halogen remaining in the intermediate layer 4 to a detectable chlorine level of 0.2 ppm or less.

In this regard, it is preferred that the washing of the intermediate layer 4 is carried out in a state that the intermediate layer 4 is being irradiated with ultrasound waves . This makes it possible to remove the halogen reliably.

[3A] Organic semiconductor layer formation step

Next , an organic semiconductor layer 5 is formed on the intermediate layer 5.

[3A-1] First, a liquid state organic semiconductor layer formation material which contains an organic semiconductor layer formation material and its precursor is applied (supplied) onto the intermediate layer 4 to form a liquid state layer or a coating layer. By using the application method, it is possible to form such an the coating layer relatively easily by applying the semiconductor layer formation material onto the intermediate layer 4.

As for the application method, the same method as mentioned above with reference to the previous step [2A-2] can be employed. Further, as for the solvent or dispersion medium for preparing the organic semiconductor layer formation material, the same solvent or dispersion medium mentioned above with reference to the previous step [2A-2] can be employed.

Further, in the case where a monomer compound having polymerizable groups is used as a precursor for the organic semiconductor material, it is preferred that a polymerization initiator is added to the organic semiconductor material. By adding such an agent, it is possible to.promote a polymerization reaction of the polymerizable groups when polymerizing the monomers by treatment such as heating treatment or light irradiation treatment, or the like.

Examples of such a polymerization initiator include, but are not limited thereto, photopolymerization initiators such as radical photopolymerization initiators and cationic photopolymerization initiators, heat polymerization initiators, and anaerobic polymerization initiators.

Examples of such cationic photopolymerization initiators include onium salt-based cationic photopolymerization initiators such as aromatic sulfouium salt-based cationic photopolymerization initiators, aromatic iodonium salt-based cationic photopolymerization initiators, aromatic diazonium cationic photopolymerization initiators, pyridium suit-based cationic photopolymerization initiators, and aromatic phosphonium salt-based cationic photopolymerization initiators; and nonionic cationic photopolymerization initiators such as iron arene complex and sulfonate ester.

Further, examples of such radical photopolymerization initiators include benzophenone-based radical photopolymerization initiators, benzoin-based radical photopolymerization initiators, acetophenone-based radical photopolymerization initiators, benzylketal-based radical photopolymerization initiators, Michler's keton-based radical photopolymerization initiators, acylphosphine oxide-based radical photopolymerization initiators, ketocoumarin-based radical photopolymerization initiators, xanthene-based radical photopolymerization initiators , and thioxanthone-based radical photopolymerization initiators.

Further, in the case where a photopolymerization initiator is used as a polymerization initiator, a sensitizer suitable for the photopolymerization initiator to be used may be added to the organic semiconductor layer formation material.

[3A-2] Next, the solvent or dispersion medium is removed from the liquid coating (organic semiconductor layer formation material) applied onto the intermediate layer 4.

In this way, in the case where the organic semiconductor layer formation material is comprised of the organic semiconductor material, an organic semiconductor layer 5 is formed on the intermediate layer 4.

Further, in the case where the organic semiconductor layer formation material is comprised of the precursor of the organic semiconductor material, a layer constituted of the precursor of the organic semiconductor material is formed on the intermediate layer 4.

As for the method for removing the solvent or dispersion medium, the same methods as those mentioned above with reference to the previous step [2A-4] can be employed.

[3A-3] Next, in the case where the organic semiconductor layer formation material is comprised of the precursor of the organic semiconductor material, the layer formed in the precedent step [3A-2] is subjected to a predetermined treatment .

By subjecting the layer to such a predetermined treatment, it is possible to polymerize the monomers (precursors) through a polymerization reaction via the polymerizable groups of the monomers which are contained as the precursors. As a result, the precursors are changed to an organic semiconductor material to thereby form an organic semiconductor layer 5.

Various methods can be used for such a predetermined treatment . Examples of such a treatment include a method for irradiating light, a method for heating, and an anaerobic treatment , and the like .

In this regard, examples of light to be irradiated include infrared ray, visual ray, ultraviolet ray. X-ray, and the like. They rays can be used alone or in combination of two or more of them. Among these rays, ultraviolet ray is particularly preferable since use of ultraviolet ray can progress the polymerization reaction of the polymerizable groups easily and reliably.

Hereinbelow, a description will be made with regard to the case where an electronic device provided with the substrate for electronic devices according to the present invention is applied to an organic EL device. In other words, a description will be made with regard to the case where the electrode, the intermediate layer, and the organic semiconductor layer of the substrate for electronic devices are respectively applied to an anode, a hole injection layer, and a hole transport layer of an organic EL device.

FIG. 2 is a cross-sectional view of an organic EL device which is one example of the electronic device according to the present invention.

The organic EL device 10 shown in FIG. 2 includes a transparent substrate 2 ' , an anode 3' provided on the substrate 2' , a hole injection layer 4' provided on the anode 3' , a hole transport layer 5' provided on the hole injection layer 4' , and a light emitting layer 6 provided on the hole transport layer 5 ' , an electron transport layer 7 provided on the light emitting layer 6, a cathode 8 provided on the electron transport layer 7, and a protecting layer 9 provided so as to cover these layers 3', 4', 5', 6, 7, and 8. The substrate 2 ' is provided as a support of the organic EL device 10, and the above-mentioned layers are laminated on the substrate 2 ' .

A constituent material of the substrate 2' is selected from materials containing the constituent materials of the above-described substrate 2 and having transparency and good optical properties .

Examples of such materials include various glass materials and the like. At least one of these materials can be used.

The average thickness of the substrate 2 ' is not limited to any specific value, but it is preferably in the range of about 0.1 to 30 mm, and more preferably in the range of 0.1 to 10 mm.

The electrode 3' is an electrode for injecting holes into the hole injection layer 4', and in this embodiment, the electrode 3 described above is used for the electrode 3 ' .

The electrode 3 ' is formed into substantially transparent (which includes transparent and colorless, colored and transparent, or translucent) so that light emitted from the light emitting layer can be visually identified.

From such a viewpoint , a material having a high work function, excellent conductivity, and a light transmitting property is preferably used as the constituent material of the anode 3' (hereinafter, referred to as "anode material").

Examples of such an anode material contained in the constituent materials for the electrode 3 described above include oxides such as ITO (Indium Tin Oxide), SnO₂, Sb-containing SnO₂, and Al-containing. ZnO, Au, Pt, Ag, Cu, and alloys containing two or more of them. At least one of these materials can be used, as an anode material..

The average thickness of the anode 3' is not limited to any specific value, but is preferably in the range of about 10 to 200 nm, and more preferably in the range of about 50 to 150 nm. If the thickness of the anode 3' is too thin, there is a case that a function of the anode 3' will not be sufficiently exhibited. On the other hand, if the anode 3' is too thick, there is a case that the light transmittance will be significantly lowered depending on, for example, the kind of anode material used, thus resulting in an organic EL device that is not suitable for practical use.

On the other hand, the cathode 8 is an electrode which injects electrons into the electron transport layer 7.

As a constituent material of the cathode 8 (hereinafter, referred to as "cathode material" ) , a material having a low work function is preferably used.

Examples of such a cathode material include Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, Yb, Ag, Cu, Al, Cs, Rb, and alloys containing two or more of them. At least one of these materials can be used as a cathode material.

Particularly, in the case where such an alloy is used as a cathode material, an alloy containing a stable metallic element such as Ag, Al, or Cu, specifically an alloy such as MgAg, AlLi, or CuLi is preferably used. The use of such an alloy as a cathode material makes it possible to improve the electron injection efficiency and stability of the cathode 8.

The average thickness of the cathode 8 is preferably in the range of about 1 nm to 1 μm, and more preferably in the range of about 100 to 400 nm. If the thickness of the cathode 8 is too thin, there is a case that the function of the cathode 5 will not be sufficiently exhibited. On the other hand, if the cathode 8 is too thick, there is a case that the light emitting efficiency of the organic EL device 10 is lowered.

Between the anode 3' and the cathode 8, the hole injection layer 4' , the hole transport layer 5' , the light emitting layer 6 , and the electron transport layer 7 are disposed in this order from the side of the anode 3 ' .

The hole injection layer 4' is provided for efficiently injecting holes, which have been injected from the anode 3', into the hole transport layer 5 ' .

For this hole injection layer 4' , the intermediate layer 4 described above is used.

The hole transport layer 5 ' has a function of transporting holes, which have been injected from the anode 3 ' , to the light emitting layer 6.

For the hole transport layer 5 ' the organic semiconductor layer 5 described above is used. In this case, as an organic semiconductor material for forming the hole transport layer 5 ' , a hole transport material having a hole transport ability can be selected from the organic semiconductor materials described above .

The average thickness of the hole transport layer 5 ' is not limited to a specific value, but it is preferably in the range of about 10 to 150 nm, and more preferably in the range of about 50 to 100 nm. If the thickness of the hole transport layer 5' is too thin, there is a case that pin holes are formed. On the other hand, if the hole transport layer 5' is too thick, there is a case that light transmittance of the hole transport layer 5' is lowered, so that chromaticity (hue) of the luminescent color of the organic EL device 10 is adversely changed.

By forming the anode 3' , the hole injection layer 4' , and the hole transport layer 5' so as to have the above structures, that is, by forming them by applying the electronic device according to the present invention, it is possible to make the hole transport ability between the these layers excellent . As a result, it is possible to improve the characteristics of the organic EL device 10 such as light emitting efficiency and the like appropriately.

The electron transport layer 7 is a layer having the function of transporting electrons, which have been injected from the cathode 8, into the light emitting layer 6.

Various materials can be used for a constituent material for the electron transport layer 7 if they have an electron transport ability. For examples, electron transport materials described above with reference to the constituent materials of the organic semiconductor layer 5 may be employed.

¹ The average thickness of the electron transport layers 7 is not limited to a specific value, but it is preferably in the range of about 1 to 100 nm, and more preferably in the range of 20 about to 50 nm. If the thickness of the electron transport layer 7 is too thin, there is a possibility that pin holes are to be formed and thereby short circuit occurs . On the other hand, if the thickness of the electron transport layer 7 is too thick, there is a case that resistance value becomes high.

Here , when a current flows between the anode 3 ' and the cathode 8 (that is, a voltage is applied across the anode 3' and the cathode 8), holes emitted from the anode 3' are transported in the hole transport layer 5 ' through the hole injection layer 4', and electrons emitted from the cathode 8 are transported in the electron transport layer 7 , so that the holes and the electrons are recombined in the light emitting layer 6. In the light emitting layer 6 , excitons are produced by energy released upon the recombination, and the excitons release energy (in the form of fluorescence or phosphorescence) or emit light when returning to the ground state.

Various materials can be used for a constituent material of the light emitting layer 6 if holes emitted from the anode 3' and electrons emitted from the cathode 8 are injected into the materials when a voltage is applied across the anode 3 ' and the cathode 8 and at that time the materials are capable of providing a filed in which the holes and the electrons are recombined.

For example, the light emitting materials described above as the constituent material of the organic semiconductor layer

5 can be used as a constituent material for the light emitting layer 6.

The average thickness of the light emitting layer 6 is not limited to any specific value, but is preferably in the range of about 10 to 150 nm, and more preferably in the range of about 50 to 100 nm. By setting the thickness of the light emitting layer 6 to a value within the above range, recombination of holes and electrons efficiently occurs , thereby enabling the light emitting efficiency of the light emitting layer 6 to be further improved.

Although, in this embodiment, each of the light emitting layer 6 , the hole transport layer 5 ' , and the electron transport layer 7 is separately provided, they may be formed into a hole-transportable light emitting layer having the functions of both the hole transport layer 5 ' and the light emitting layer

6 or an electron-transportable light emitting layer having the functions of both the electron transport layer 7 and the light emitting layer 6. In these cases, an area in the vicinity of the boundary between the hole-transportable light emitting layer and the electron transport layer 7 or an area in the vicinity of the boundary between the electron-transportable light emitting layer and the hole transport layer 5 ' functions as the light emitting layer 6.

Further, in the case where the hole-transportable light emitting layer is used, holes injected from the anode into the hole-transportable light emitting layer are trapped by the electron transport layer, and in the case where the electron-transportable light emitting layer is used, electrons injected from the cathode into the electron-transportable light emitting layer are trapped in the electron-transportable light emitting layer. In both cases, there is an advantage in that the recombination efficiency of holes and electrons can be improved.

As described above, the protection layer 9 is provided so as to cover the layers 3', 4', 5', 6, 7 and 8 constituting the organic EL device 10. This protection layer 9 has the function of hermetically sealing the layers 3', 4', 5', 6, 7 and 8 constituting the organic EL device 10 to shut off oxygen and moisture. By providing such a protection layer 9, it is possible to obtain the effect of improving the reliability of the organic EL device 10 and the effect of preventing the alteration and deterioration of the organic EL device 10.

Examples of a constituent material of the protection layer 9 include Al, Au, Cr, Nb, Ta and Ti, alloys containing them, silicon oxide, various resin materials, and the like. In this regard, it is to be noted that in the case where a conductive material is used as a constituent material of the protection layer 9, it is preferred that the insulating films are provided between the protection layer 9 and each of the layers 3 ' , 4 ' , 5', 6, 7 and 8, respectively, to prevent a short circuit therebetween, as needed.

In the foregoing, an explanation has been made with regard to the case where the electrode, the intermediate layer and the organic semiconductor layer of the electronic device of this embodiment are respectively applied to the anode, the hole injection layer and the hole transport layer of the organic EL device. However, the present invention is not limited to such a case, and the electrode and the organic semiconductor layer of the present invention may be respectively applied to a cathode and an electron transport layer of an organic EL device and the intermediate layer of the present invention may be disposed between the cathode and the electron transport layer as an electron injection layer.

Such an organic EL device 10 can be manufacture as follows , for instance.

[IB] Anode formation step

First, a substrate 2' is prepared, and then an anode 3' is formed on the substrate 2' . The anode 3' can be formed using the same method as described above with reference to the step [IA].

[2B] Hole injection layer formation step

Next, a hole injection layer 4' is formed on the anode 3' . The hole injection layer 4' can be formed using the same method as described above with reference to the step [2A].

[3B] Hole transport layer formation step

Next , a hole transport layer 5 ' is formed on the hole injection layer 4' . The hole transport layer 5' can be formed using the same method described above with reference to the step [ 3A ] .

[4B] Next, a light emitting layer 6 is formed on the hole transport layer 5 ' . The light emitting layer 6 can be formed by applying a light emitting layer material (light emitting layer formation material) obtained by dissolving or dispersing the light emitting material described above into a solvent or dispersion medium onto the hole transport layer 5 ' , for instance . As a solvent or dispersion medium into which the light emitting material is dissolved or dispersed, the same solvents or dispersion mediums as mentioned above with reference to the step [2A-2] can be used.

Further, as a method for applying the light emitting layer material onto the hole transport layer 5 ' , the same application methods as described above with reference to the step [2A-2] can be used.

[5B] Next, an electron transport layer 7 is formed on the light emitting layer 6. The electron transport layer 7 can be formed in the same manner as the light emitting layer 6. Namely, the electron transport layer 7 can be formed using the electron transport material described above and the method described above with reference to the light emitting layer 6.

[6B] Cathode formation step

Next, a cathode 5 is formed on the electron transport layer 7. The cathode 5 can be formed using a vacuum deposition method, a spattering method, a bonding of a metal foil, or the like.

[7B] Protective cover formation step

Next, a protective cover 9 is formed so as to cover the anode 3 ' , the hole injection layer 4 ' , the hole transport layer 5 ' , the light emitting layer 6 , the electron transport layer 7 and the cathode 8.

The protective cover 9 may be formed (or provided) by bonding a box-shaped protective cover constituted from the material mentioned above to the laminated body including these layers with a curable resin (adhesive) .

As such a curable resin, either of thermosetting resins, photocurable resins, reactive curable resins, or anaerobic curable resins may be used.

The organic EL device 10 is manufactured through the above steps .

The organic EL device 10 can be used for a display, for example, but it can also be used for various optical purposes such as a light source and the like.

Further, in the case where the organic EL device 10 is used for a display device, a number of organic EL devices 100 are provided on the display device. One example of such a display device is shown below.

FIG. 3 is a cross-sectional view of a display device provided with a number of organic EL devices .

As shown in FIG. 3, a display device 100 includes a base 20 and a number of organic EL devices 10 provided on the base 20.

The base 20 includes a substrate 21 and a circuit section 22 formed on the substrate 21. The circuit section 22 includes a protective layer 23 provided on the substrate 21 and formed from a titanium oxide layer, a driving TFT (switching element) 24 formed on the protective layer 23, a first insulation layer 24, and a second insulation layer 26. The driving TFT 24 includes a semiconductor layer 241 made of a silicon, a gate insulation layer 242 formed on the semiconductor layer 241, a gate electrode 243 formed on the gate insulation layer 242, a source electrode 244, and a drain electrode 245.

The organic EL devices 10 are provided on the circuit section 22 having the above structure so as to be associated with the respective driving TFTs 24. Further, the adjacent organic EL devices 10 are partitioned by the first partitioning wall portion 31 and a second partitioning wall portion 32.

In this embodiment , an anode 3 ' of each organic EL devices 10 constitutes a pixel electrode, and it is electrically connected to the drain electrode 245 of the corresponding driving TFT 24 through a wiring 27.

Further, a seal member (not shown in the drawing) is joined to the base 20 so as to cover the respective organic EL devices 10 to thereby seal the organic EL devices 10.

The display device 100 may be formed into a single color display type, but the display device 100 can display a color image by selecting light emitting materials used for the respective' organic EL devices 10.

The organic EL devices 10 (the display device 100) can be used for various electronic equipment .

FIG. 4 is a perspective view which shows the structure of a personal mobile computer (or a personal notebook computer) which is one example of the electronic equipment provided with the electronic device according to the present invention. In FIG. 4, a personal computer 1100 is composed, from a main body 1104 provided with a keyboard 1102 and a display unit 1106 having a display (screen). The display unit 1106 is rotatably supported, by the main body 1104 via a hinge structure.

In the personal computer 1100, the display (screen) of the display unit 1106 is constructed from the organic EL devices 10 described above.

FIG. 5 is a perspective view which shows the structure of a mobile phone (including a personal handyphone system (PHS) ) which is the other example of the electronic equipment according to the present invention.

The mobile phone 1200 shown in FIG. 5 includes a plurality of operation buttons 1202, an earpiece 1204, a mouthpiece 1206, and a display.

In this mobile phone 1200, the display is constructed from the organic EL devices 10 as described above.

FIG. 6 is a perspective view which shows the structure of a digital still camera which is still other example of the electronic equipment according to the present invention. In this drawing, interfacing to external devices is simply illustrated.

In a conventional camera, a silver salt film is exposed to the optical image of an object. On the other hand, in the digital still camera 1300, an image pickup device such as a CCD (Charge Coupled Device) generates an image pickup signal (or an image signal) by photoelectric conversion of the optical image of an object.

In the rear surface of a case (or a body) 1302 of the digital still camera 1300, there is provided a display which provides an image based on the image pickup signal generated by the CCD. That is, the display functions as a finder which displays the object as an electronic image.

In this digital still camera 1300, the display is constructed from the organic EL devices 10 as described above.

In the inside of the case, there is provided a circuit board 1308. The circuit board 1308 has a memory capable of storing an image pickup signal.

In the front surface of the case 1302 (in FIG. 6, the front surface of the case 1302 is on the back side) , there is provided a light receiving unit 1304 including an optical lens (an image pickup optical system) and a CCD.

When a photographer presses a shutter button 1306 after checking an object image on the display, an image pickup signal generated by the CCD at that time is transferred to the memory in the circuit board 1308 and then stored therein.

Further, in the side surface of the case 1302 of the digital still camera 1300, there are provided a video signal output terminal 1312 and an input-output terminal for data communication 1314. As shown in FIG. 6, when necessary, a television monitor 1430 and a personal computer 1440 are connected to the video signal output terminal 1312 and the input-output terminal for data communication 1314, respectively. In this case, an image pickup signal stored in the memory of the circuit board 1308 is outputted to the television monitor 1430 or the personal computer 1440 by carrying out predetermined operations .

The electronic equipment according to the present invention can be applied not only to the personal computer (which is a personal mobile computer) shown in FIG.4, the mobile phone shown in FIG. 5, and the digital still camera shown in FIG.6 but also to a television set, a video camera, a view-finer or monitor type of video tape recorder, a laptop-type personal computer, a car navigation device, a pager, an electronic notepad (which may have communication facility) , an electronic dictionary, an electronic calculator, a computerized game machine, a word processor, a workstation, a videophone, a security television monitor, an electronic binocular, a POS terminal, an apparatus provided with a touch panel (e.g. , a cash dispenser located on a financial institute, a ticket vending machine), medical equipment (e.g., an electronic thermometer, a sphygmomanometer, a blood glucose meter, an electrocardiograph monitor, ultrasonic diagnostic equipment, an endoscope monitor), a fish detector, various measuring instruments, gages (e.g., gages for vehicles, aircraft, and boats and ships), a flight simulator, various monitors, and a projection display such as a projector.

The substrate for electronic devices, the electronic device provided with the substrate, and the electronic equipment provided with the electronic device according to the present invention have been described based on the embodiments shown in the drawings, but the present invention is not limited thereto.

For example, the substrate for electronic devices according to the present invention may be applied to a photoelectric conversion element and a thin film transistor in addition to the organic EL device (element) described above.

Examples

Next, the present invention will be described with reference to the actual examples . 1. Synthesis of compound

First, a compound (A) described below was prepared.

6- (p-aminophenyl)hexanol was treated with 4-methoxybenzylbromide and sodium hydride in anhydrous dimethylformamide to transform hydroxyl groups into benzyl ether groups and then it was protected.

Next, 1 mol of the obtained compound was dissolved in 150 mL of acetic acid, and acetic anhydride was dropped therein at room temperature and then they were stirred. After the completion of the reaction, a solid matter precipitated was filtered and then dried after washing with water to obtain a dry substance.

Next, 0.37 mol of the thus obtained substance, 0.66 mol of l-bromo-4-hexylbenzene, 1.1 mol of potassium carbonate, copper powder, and iodine were mixed, and the mixture was heated at a temperature of 200°C. After the heated mixture was cooled down, 130 mL of isoamyl alcohol, 50 mL of pure water and 0.73 mol of potassium hydroxide were added to the mixture, and it was stirred and then dried to thereby obtain a compound.

Next, 130 mmol of the thus obtained compound, 62 mmol of 4, 4 ' -diiodobiphenyl, 1.3 mmol of palladium acetate, 5.2 mmol of t-butylphosphine, 260 mmol of sodium t-butoxide, and 700 mL of xylene were mixed, and then they were stirred at a temperature of 120⁰C. Thereafter, the mixture was cooled for crystallization .

The thus obtained compound was then reduced by hydrogen gas using Pd-C catalyst so that transformation was made from the benzyl ether groups to the hydroxyl groups to carry out deprotection . Next, 100 mmol of the compound and 2000 mmol of epichlorohydrin were added to 50% of sodium hydroxide solution to which a small amount of a hydrogen sulphate of tetra-n-butylammonium (phase transfer catalyst) had been added, and then they were stirred for 10 hours at room temperature. Thereafter, the mixture was cooled for crystallization to obtain a compound.

Then, the thus obtained compound was confirmed to be the following compound (A) by means of amass spectrum (MS) method, a ¹H-nuclear magnetic resonance (¹H-NMR) spectrum method, a ¹³C-nuclear magnetic resonance (¹³C-NMR) spectrum method, and a Fourier transform infrared absorption (FT-IR) spectrum method.

2. Manufacture of EL device Five organic EL devices were manufactured in each of the following Examples and Comparative Examples .

(Example IA)

IA First, an ITO electrode (an anode) was formed on a transparent glass substrate having an average thickness of 0.5 mm by a vacuum deposition method so as to have an average thickness of 100 nm.

2A Next, the ITO electrode (anode) was heated in an atmosphere of 20 vol% of chlorine at a temperature of 100°C for 30 minutes to thereby chlorinate the surface of the ITO electrode.

3A Next, a N,N-dimethylformamide solution containing 1.0 wt% of 1 , 10-phenanthroline (which is represented by the above-mentioned general formula (I)) was applied onto the chlorinated surface of the ITO electrode by a spin coating method.

4A Next, such an ITO electrode was heated in an atmosphere of argon gas at a temperature of 150⁰C for 60 minutes in a dark place so that the chloride on the surface of the ITO electrode was removed and the 1, 10-phenanthroline was coordinated on the surface.

5A Next, the N,N-dimethyIformamide solution was removed by drying it under the condition of a temperature of 100°C and a pressure of 10 Pa to thereby form a hole injection layer constituted of the 1, 10-phenanthroline and having an average thickness of 28 nm.

6A Next, the thus formed hole injection layer formed on the ITO electrode was washed with diethyl ether wile irradiating it with ultrasound waves _> and then it was further

the ligands used for forming the respective hole injection layers were changed as shown in Table 1.

(Example 22A)

Organic EL devices were manufactured in the same manner as in the Example IA except that the formation of the hole transport layer in the above-mentioned step 7A was carried out as follows .

The compound (A) was used as a diphenylamine derivative, and the compound (A) and a cationic photopolymerization initiator ("FC-508" produced by Sumitomo Thee-M in a weight ratio of 99 : 1 were dissolved in dichloroethane to thereby obtain a hole transport layer formation material.

First, the hole transport layer formation material was applied onto the hole injection layer by a spin coating method and then it was dried.

Then, the hole transport layer formation material was irradiated with ultraviolet rays having a wavelength of 365 nm from a mercury lamp ("UM-452", produced by USHIO Inc. ) through a filter at an intensity of irradiation of 500 mW/cm² for 60 minutes in an atmosphere to polymerize the compound (A) , so that a hole transport layer having an average thickness of 50 nm was formed .

(Examples 23A and 24A)

In each of the Examples 23A and 24A, organic EL devices were manufactured in the same manner as in the Example 22A except that the ligands used for forming the hole injection layers were changed as shown in Table 1.

(Comparative Example IA)

Organic EL devices were manufactured in the same manner as in the Example IA except that the formation of the hole injection layer was omitted.

(Comparative Example 2A)

Organic EL devices were manufactured in the same manner as in the Example IA except that the formation of the hole injection layer in the step 2A to the step 6A was carried out by supplying copper phthalocyanine by a vacuum deposition method.

(Example IB)

IB First, an ITO electrode (an anode) was formed on a transparent glass substrate having an average thickness of 0.5 mm by a vacuum deposition method so as to have an average thickness of 100 nm.

2B Next, on the thus formed ITO electrode (anode), a xylene ' solution containing 2.0 wt% of N, N ' -diphenyl-N,N ' -bis ( 3-methylphenyl) - 1 , 1 ' -biphenyl-4 , 4 ' -d iamine (TPDl) was applied by a spin coating method, and then it was dried to thereby obtain a hole transport layer having an average thickness of 50 nm.

3B Next, a xylene solution containing 1.7 wt% of poly( 9 , 9-dioctyl-2,7-divinylenefluorenyl) -alt-co ( anthracene -9,10-diyl) (weight average molecular weight was 200,000) was applied by a spin coating method, and then it was dried to thereby obtain a light emitting layer having -an average thickness of 50 nm.

4B Further, an AlLi electrode (a cathode) was formed on a transparent glass substrate having an average thickness of 0.5 mm by a vacuum deposition method so as to have an average thickness of 300 nm.

5B Next , the AlLi electrode was heated in an atmosphere of 20 vol% of chlorine at a temperature of 100°C for 30 minutes to thereby chlorinate the surface of the ITO electrode.

6B Next, a N,N-dimethylformamide solution containing 1.0 wt% of 1,10-phenanthroline (which is represented by the above-mentioned general formula (I)) was applied onto the chlorinated surface of the AlLi electrode by a spin coating method.

7B Next, such an ITO electrode was heated in an atmosphere of argon gas at a temperature of 150°C for 60 minutes in a dark place so that the chloride on the surface of the ITO electrode was removed and the 1,10-phenanthroline was coordinated on the surface.

8B Next, the N,N-dimethylformamide solution was removed by drying it under the condition of a temperature of 100°C and a pressure of 10 Pa to thereby form an electron injection layer constituted of the 1,10-phenanthroline and having an average thickness of 30 nm.

9B Next, the hole injection layer formed on the AlLi electrode was washed with diethyl ether wile irradiating it with ultrasound waves, and then it was further washed by ultra-pure water so that the condensation of chloride in the layer was 0.2 ppm or lower.

1OB Next, on the thus formed electron injection layer. a layer made of 8-hydroxyquinoline aluminum (AIq₃) was formed by a vacuum deposition to thereby form an electron transport layer having an average thickness of 20 nm.

HB Next, in a state that the light emitting layer was faced to the electron transport layer, they were subjected to a heat treatment in an atmosphere at a temperature of 80°C for 50 minutes while they were being pressed together, thereby joining the light emitting layer and the electron transport layer .

12B Next, a UV curable resin was applied so as to cover the side surfaces of the thus formed layers by an ink-jet method, and then the UV curable resin was hardened by irradiation with ultraviolet rays to seal them to thereby obtain an organic EL device .

(Examples 2B to 8B)

In each of the Examples 2B to 8B, organic EL devices were manufactured in the same manner as in the Example IB except that the ligands used for forming the respective electron injection layers were changed as shown in Table 2.

(Comparative Example IB)

Organic EL devices were manufactured in the same manner as in the Example IB except that the formation of the electron injection layer was omitted.

3. Evaluation

The luminous brightness (cd/m²), the maximum luminous efficiency (lm/W) , and the time that elapsed before the luminous brightness became half of the initial value (that is, a half-life) of each of the organic EL .devices obtained in the Examples and the Comparative Examples mentioned above were measured.

In this regard, it is to be noted that the current density and the luminous brightness were measured by applying a voltage of 6V across the ITO electrode and the AlLi electrode.

The measurement values (that is, the luminous brightness, the maximum luminous efficiency, and the half-life) of each of the Examples IA to 24A and the Comparative Example 2A were evaluated according to the following four criteria, respectively, based on the measurement values of the Comparative Example IA as a reference.

A: The measurement value was 1.50 times or more that of the Comparative Example IA.

B: The measurement value was 1.25 times or more but less than 1.50 times that of the Comparative Example IA.

C: The measurement value was 1.00 times or more but less than 1.25 times that of the Comparative Example IA.

D: The measurement value was 0.75 times or more but less than 1.00 times that of the Comparative Example IA.

The evaluation results are shown in the following Table IA and Table IB.

As shown in Table IA and Table IB, all the organic EL devices of the Examples were superior to the organic EL devices of the Comparative Examples in their luminous brightness, maximum luminous efficiency, and half-life.

From these results, it is supposed that according to each of the organic EL devices of the present invention, adhesion at the boundary between the anode and the hole injection and adhesion at the boundary between the hole transport layer and the hole injection layer were improved, and thus the hole transport ability in these layers was improved appropriately.

This tendency could be seen in each of the Examples 22A to 24A more conspicuously. This is supposed to result from the fact that in each of these Examples since the hole transport layer was constituted of a polymer of the compound (A) , adhesion at the boundary between the hole injection layer and the hole transport layer was further improved.

Further, in the organic EL devices manufactured using the compounds containing the ligands each having a straight-chain alkyl group having 2 to 8 carbon atoms as the substituent A⁰ or the substituent Z⁰ (that is, the Examples 4A, 5A, HA, 12A, 17A and 18A) , there were tendency that the maximum luminous efficiency and the half-life were improved. This is supposed to result from the fact that the interaction between the conjugated structures were decreased in each hole injection layer due to the straight-chain alkyl groups.

In addition to the above Examples , organic EL devices were manufactured in the same manner as the Examples IA to 19A except that IZO was used as a constituent material of the anode and N,N' -di(l-naphthyl)-N,N' -diphenyl-1 , 1 ' -biphenyl-4 , 4 ' -diamin e(α-NPD) was used as a constituent material of each hole transport layer. These organic EL devices were evaluated according to the above evaluation methods, and in these organic EL devices substantially the same results as those mentioned above could also be obtained.

Further, the measurement values (that is, the luminous brightness , the maximum luminous efficiency, and the half-life) of each of the Examples IB to 8B were evaluated according to the following four criteria, respectively, based on the measurement values of the Comparative Example IB as a reference.

A: The measurement value was 1.50 times or more that of the Comparative Example IB.

B: The measurement value was 1.25 times or more but less than 1.50 times that of the Comparative Example IB.

C: The measurement value was 1.00 times or more but less than 1.25 times that of the Comparative Example IB.

D: The measurement value was 0.75 times or more but less than 1.00 times that of the Comparative Example IB.

The evaluation results are shown in the following Table 2.

As shown in Table 2 , all the organic EL devices of the Examples (that is, in the organic EL devices each having the substrate for electronic devices according to the present invention) were superior to the organic EL devices of the Comparative Example in their luminous brightness, maximum luminous efficiency, and half-life.

From these results, it is supposed that according to each of the organic EL devices of the present invention, adhesion at the boundary between the cathode and the electron transport layer and adhesion at the boundary between the electron transport layer and the electron injection layer were improved, and thus the electron transport ability in these layers was improved appropriately.

Industrial Utilization

According to the substrate for electronic devices of the present invention, since the substrate for electronic devices comprises an organic semiconductor layer mainly comprised of an organic semiconductor material having a conjugated structure, an electrode containing metal atoms; and an intermediate layer provided between the organic semiconductor layer and the electrode in contact with both the organic semiconductor layer and the electrode, wherein the intermediate layer contains as its major component a ligand having at least one conjugated structure and at least one ligand atom that coordinates to one of the metal atoms, the ligand atom coordinates to the metal atom so that the ligand is chemically bonded to the metal atom, that is, to the surface of the electrode. As a result, the intermediate layer exhibits excellent adhesion with the electrode, so that the difference in the carrier transport abilities in the vicinity of the boundary between the electrode and the intermediate layer can be made small. Further, since the ligand has a conjugated structure, the ligand exhibits excellent compatibility to the organic semiconductor material having a conjugated structure, and therefore the intermediate layer can have excellent adhesion to the organic semiconductor layer. Furthermore, since both the intermediate layer and the semiconductor layer have a conjugated structure, it is possible to make the difference in the carrier transport abilities of these layers small. Therefore, when the carriers (holes or electrons) are transferred from the electrode to the side of the organic semiconductor material, the above mentioned results are obtained synergistically, and thus the carriers which have been injected into the intermediate layer from the electrode can be transferred to the conjugated structures from the ligand atoms successively, so that the carriers are smoothly transferred to the organic semiconductor layer. In other words , the substrate for electronic devices having such an intermediate layer between the electrode and the semiconductor layer can exhibit an excellent carrier transport ability. Further, the electronic device provided with the substrate for electronic and the electronic equipment provided with the electronic device can have high reliability. Thus, the present invention has industrial utilization under PCT.

Claims

1. A substrate for electronic devices, comprising: an organic semiconductor layer mainly comprised of an organic semiconductor material having a conjugated structure; an electrode containing metal atoms; and an intermediate layer provided between the organic semiconductor layer and the electrode in contact with both the organic semiconductor layer and the electrode, wherein the intermediate layer contains as its major component a ligand having at least one conjugated structure and at least one ligand atom that coordinates to one of the metal atoms .

2. The substrate for electronic devices as claimed in claim 1 , wherein the total number of carbon atoms in the ligand is 40 or less.

3. The substrate for electronic devices as claimed in claim 1 , wherein the ligand is a unidentate ligand having one ligand atom that coordinates to the metal atom.

4. The substrate for electronic devices as claimed in claim 3 , wherein the unidentate ligand is of the type that the ligand atom is contained in the conjugated structure.

5. The substrate for electronic devices as claimed in claim 1, wherein the ligand is a multidentate ligand having two or more ligand atoms that coordinate to the metal atom.

6. The substrate for electronic devices as claimed in claim

5, wherein the multidentate ligand is of the type that all the ligand atoms are contained in the conjugated structure.

7. The substrate for electronic devices as claimed in claim

6 , wherein the multidentate ligand is -composed of at least one of compounds represented by the following general formulas (1) and ( 2 ) :

8. The substrate for electronic devices as claimed in claim 7, wherein the straight-chain alkyl group has 2 to 8 carbon atoms .

9. The substrate for electronic devices as claimed in claim

7, wherein in each of the compounds each substituent A⁰S is bonded to a pyridine ring at its 3 or 4-position.

10. The substrate for electronic devices as claimed in claim 5, wherein the multidentate ligand is of the type that a part of the ligand atoms is contained in the conjugated structure.

11. The substrate for electronic devices as claimed in claim 10, wherein the multidentate ligand is composed of at least one of compounds represented by the following general formulas ( 3 ) to (9):

where in each of the general formulas a substituent X⁰ represents a nitrogen atom, an oxygen atom, a sulfur atom, or a selenium atom, a substituent Y⁰ represents a hydroxy group, a mercapto group, an amino group or a carboxy group, and a substituent Z⁰ represents a hydrogen atom, a chlorine atom, or a straight-chain alkyl group having 1 to 10 carbon atoms.

12. The substrate for electronic devices as claimed in claim 11, wherein the straight-chain alkyl group has 2 to 8 carbon atoms .

13. The substrate for electronic devices as claimed in claim 11, wherein when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas (3), (8) and (9), the substituent Z⁰ is bonded to a benzene ring at its 3 or 4 position.

14. The substrate for electronic devices as claimed in claim 11, wherein when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas (4) and (5), the substituent Z⁰ is bonded to a heteroaromatic ring at its 3 or 4 position.

15. The substrate for electronic devices as claimed in claim 11, wherein when the multidentate ligand is composed of any one of the compounds represented by the above-mentioned general formulas (6) and (7), the substituent Z⁰ is bonded to a benzene ring at its 4 or 5 position.

16. The substrate for electronic devices as claimed in claim 5 , wherein the multidentate ligand is of the type that all of the ligand atoms are existed out of the conjugated structure.

17. The substrate for electronic devices as claimed in claim 16, wherein the multidentate ligand is composed of a compound represented by the following general formula (10):

(10)

18. The substrate for electronic devices as claimed in claim 17, wherein the straight-chain alkyl group has 2 to 8 carbon atoms .

19. The substrate for electronic devices as claimed in claim 1 177,, wwhheerreeiinn tthhee ssuubbssttituent Z⁰ is bonded to a benzene ring at its 3 or 4 position.

20. The substrate for electronic devices as claimed in claim 1, wherein the metal atom is indium.

21. The substrate for electronic devices as claimed in claim 1, wherein the organic semiconductor material is comprised of a polymer obtained by polymerizing monomers each having at least one polymerizable group at their polymerizable groups .

22. The substrate for electronic devices as claimed in claim 1, wherein each of the monomers is a compound represented by the following general formula (Al) or (A2)

wherein two R¹S are the same . or different and each independently represents a straight-chain alkyl group having 2 to 8 carbon atoms , and four R²S are the same or different and each independently represents a hydrogen atom, a methyl group or an ethyl group, Y represents a group containing at least one substituted or unsubstituted aromatic hydrocarbon ring or substituted or unsubstituted heterocyσle, and two X¹S are the same kind of substituent represented by any one of the following general formulas (Bl) to (B3), in which the number of carbon atoms of the two X¹S are the same as or different from to each other; or

wherein eight R³S are the same or different and each independently represents a hydrogen atom, a methyl group, or an ethyl group, Y represents a group containing at least one substituted or unsubstituted aromatic hydrocarbon ring or substituted or unsubstituted heterocycle, and X², X³, X⁴ and X⁵ are the same kind of substituent which is represented by any one of the following general formulas (Bl) to (B3), in which the number of carbon atoms of X², X³, X⁴ and X⁵ are the same as or different from to each other.

wherein n¹ is an integer of 2 to 8 , n² is an integer of

3 to 8, m is an integer of 0 to 3, Z¹ represents a hydrogen atom oorr aa mmeetthhyyll ggrroouupp,, aanndd ZZ²² represents a hydrogen atom, a methyl group or an ethyl group .

23. An electronic device provided with the substrate for electronic devices defined in claim 1.

24. Electronic equipment provided with the electronic device defined in claim 23.