CN114695700A - Carrier transmission material, preparation method thereof and quantum dot light-emitting diode - Google Patents

Carrier transmission material, preparation method thereof and quantum dot light-emitting diode Download PDF

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CN114695700A
CN114695700A CN202011630749.6A CN202011630749A CN114695700A CN 114695700 A CN114695700 A CN 114695700A CN 202011630749 A CN202011630749 A CN 202011630749A CN 114695700 A CN114695700 A CN 114695700A
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quantum dot
metal oxide
dot light
tetraazacyclotetradecane
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聂志文
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TCL Technology Group Co Ltd
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Abstract

The invention relates to the technical field of quantum dot light-emitting diode materials, and provides a carrier transmission material, a preparation method thereof and a quantum dot light-emitting diode. The carrier transport material provided by the invention comprises 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide semiconductor nanocrystalline. According to the invention, 1,4,8, 11-tetraazacyclotetradecane is used as a ligand to perform coordination modification on the metal oxide semiconductor nanocrystal, so that the defect state on the surface of the metal oxide semiconductor nanocrystal particle material can be effectively passivated, the adverse effect on the quantum dot material when the metal oxide semiconductor nanocrystal particle material is in contact with a quantum dot light emitting layer is avoided, and the problems of interface fluorescence quenching and non-Auger recombination easily caused are reduced. In addition, the passivation of the 1,4,8, 11-tetraazacyclotetradecane ligand to the metal oxide semiconductor nanocrystal can also obviously reduce the roughness of a film formed by a carrier transmission material, improve the compactness of the film, contribute to inhibiting the leakage current problem of a device and improve the working stability and performance of the device.

Description

Carrier transmission material, preparation method thereof and quantum dot light-emitting diode
Technical Field
The invention belongs to the technical field of quantum dot light-emitting diode materials, and particularly relates to a carrier transmission material, a preparation method of the carrier transmission material and a quantum dot light-emitting diode.
Background
As a novel thin film light-emitting display device, a Quantum dot light-emitting diode (QLED) has inherited the unique photoelectric properties of Quantum dots, and thus represents an important commercial application value, the industry has started to focus on Quantum dot display technologies, such as: QD Vision and Nanosys in the united states, LG and samsung in korea, TCL and kyoto in china, and the like. Therefore, quantum dot display technology is certainly a new pet in the display and lighting market as a new display technology. Compared with the existing Liquid Crystal Display (LCD) and Organic light-emitting semiconductor (OLED) technologies in the display market, the QLED has incomparable advantages, which are mainly expressed as: the LED display panel has the advantages of low cost, high brightness, long service life, low energy consumption, high color gamut, simple process, suitability for large screens and the like, and is expected to become an excellent candidate for next-generation flat panel display.
Through continuous optimization and development for more than thirty years, the quantum dot yield of the quantum dot material can reach a level of 95-100%, but the conversion efficiency of the QLED device prepared based on the high-performance quantum dot material is far lower than that of the luminescent material. The fundamental reason is that the electron and hole recombination in the luminescent layer of the quantum dot is extremely unbalanced, so that most of carriers are subjected to nonradiative Auger recombination, and the luminescent efficiency of the quantum dot is reduced. Meanwhile, the charge imbalance problem also causes the phenomenon of charging of the luminescent layer, and the problems of quenching quantum dot fluorescence, generating larger leakage current and the like are caused, so that the luminous efficiency of the QLED is reduced. The existing high-performance device structure is generally a hybrid structure using organic and inorganic transport materials, wherein the electron transport materials are commonly prepared based on a low-temperature solution method. The electron transport material prepared by the method is small in size (2-10 nm), simple in preparation method, low in temperature and low in cost, and is easy to prepare a thin film material. Such as: the ZnO film prepared by adopting a low-temperature solution method is used as an Electron Transport Layer (ETL) to realize the QLED device with the best performance at present. However, the electron transport material prepared by the method has a bare surface and a high surface free energy, and the surface energy is easily reduced by agglomeration, so that the solution is easy to get turbid, and the subsequent application of the electron transport material in QLED devices is not favorable, especially the requirement of large-scale production is not favorable. On the other hand, the ZnO electron transport layer has many surface defect states, and when contacting with quantum dots, excitons at the interface are easily quenched, thereby further affecting the performance of the device.
Disclosure of Invention
The invention aims to provide a carrier transmission material, a preparation method of the carrier transmission material and a quantum dot light-emitting diode, and aims to solve the technical problem that the existing zinc oxide electronic transmission layer has more surface defect states.
In order to achieve the purpose of the application, the technical scheme adopted by the invention is as follows:
in one aspect, the invention provides a carrier transport material comprising a 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide semiconductor nanocrystal.
On the other hand, the invention provides a preparation method of the carrier transport material, which comprises the following steps:
providing metal acetate, 1,4,8, 11-tetraazacyclotetradecane, organic amine, a precipitating agent and a solvent, wherein a metal element in the metal acetate is a metal element in a metal oxide semiconductor nanocrystal;
mixing the metal acetate, the 1,4,8, 11-tetraazacyclotetradecane, the organic amine and the solvent, and carrying out hydrolysis reaction on the metal salt to obtain a solution containing the 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystal;
and mixing the solution with the precipitant, and performing solid-liquid separation to obtain the solid which is the metal oxide semiconductor nanocrystal modified by 1,4,8, 11-tetraazacyclotetradecane coordination.
In another aspect, the invention provides a quantum dot light emitting diode, which includes an anode and a cathode that are oppositely arranged, and a quantum dot light emitting layer and an electron transport layer that are stacked and arranged between the anode and the cathode, where the electron transport layer includes the carrier transport material of the invention, or includes the carrier transport material prepared by the method for preparing the carrier transport material of the invention.
In a final aspect, the present invention provides a method for preparing a quantum dot light emitting diode, comprising the steps of:
providing an anode, and preparing a quantum dot light-emitting layer on the surface of the anode;
providing a metal oxide semiconductor nanocrystalline dispersion liquid modified by 1,4,8, 11-tetraazacyclotetradecane coordination, and coating the dispersion liquid on the surface of the quantum dot light-emitting layer, which is far away from the anode, to obtain an electron transmission layer;
preparing a cathode on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer, so as to obtain a quantum dot light-emitting diode;
or
Providing a cathode and a metal oxide semiconductor nanocrystalline dispersion liquid modified by 1,4,8, 11-tetraazacyclotetradecane coordination, and coating the dispersion liquid on the surface of the cathode to obtain an electron transport layer;
preparing a quantum dot light-emitting layer on the surface of the electron transport layer, which is far away from the cathode;
and preparing an anode on the surface of the quantum dot light-emitting layer deviating from the electron transmission layer to obtain the quantum dot light-emitting diode.
According to the invention, 1,4,8, 11-tetraazacyclotetradecane is used as a ligand, and the coordination modification is carried out on the metal oxide semiconductor nanocrystal, so that the obtained carrier transport material has good monodispersity, the possibility of mutual agglomeration among material particles is reduced, and the stability of the material is improved. The 1,4,8, 11-tetraazacyclotetradecane can effectively passivate the defect state on the surface of the metal oxide semiconductor nanocrystalline particle material, thereby avoiding the adverse effect on the quantum dot material when contacting with a quantum dot light-emitting layer, and reducing the problems of interface fluorescence quenching and non-Auger recombination which are often caused by the metal oxide semiconductor nanocrystalline. In addition, the passivation of the 1,4,8, 11-tetraazacyclotetradecane ligand to the metal oxide semiconductor nanocrystal can also obviously reduce the roughness of a film formed by a carrier transmission material, improve the compactness of the film, contribute to inhibiting the leakage current problem of a device and improve the working stability and performance of the device.
The preparation method of the current carrier transmission material provided by the invention adopts a simple and effective self-passivation strategy, reduces the defect state problem of the metal oxide semiconductor nanocrystal by utilizing a Lewis alkaline environment, and improves exciton recombination so as to improve the performance of the device. Firstly, because the 1,4,8, 11-tetraazacyclotetradecane ligand is introduced in the process of preparing the metal oxide semiconductor nanocrystal, the adverse effect caused by adding additional ligand after the metal oxide semiconductor nanocrystal is prepared can be effectively avoided. Secondly, in the preparation method of the carrier transport material provided by the invention, 1,4,8, 11-tetraazacyclotetradecane is used as a ligand and is coordinated with metal ions on the surface of the metal oxide semiconductor nano material, so that the defect state of the surface of the metal oxide semiconductor nano crystal material is effectively passivated. By reducing the surface defect state of the metal oxide semiconductor nanocrystal, the obtained carrier transmission material is prevented from causing adverse effects on the quantum dot material when being in contact with the quantum dot light emitting layer in a device, and the problems of interface fluorescence quenching and non-Auger recombination easily caused by the metal oxide semiconductor nanocrystal are reduced; thirdly, the preparation method of the invention carries out coordination modification on the metal oxide semiconductor nanocrystal by using 1,4,8, 11-tetraazacyclotetradecane, and the obtained carrier transmission material has excellent monodispersity, is beneficial to reducing the possibility of mutual agglomeration among particles and improving the stability of the material; the roughness of a film formed by the carrier transport material can be obviously reduced, the compactness of the film is improved, the leakage current problem of the device is favorably inhibited, and the working stability and the performance of the device are improved.
The electron transmission layer of the quantum dot light-emitting diode provided by the invention contains the metal oxide nanocrystal coordinated and modified by 1,4,8, 11-tetraazacyclotetradecane, so that the surface defect state is less, and the quantum dot light-emitting diode has good compactness and stability. When the electron transmission layer is in contact with the quantum dot light-emitting layer, adverse effects on a quantum dot material are avoided, the problems of interface fluorescence quenching and non-Auger recombination are reduced, the problem of leakage current of the quantum dot light-emitting diode is also favorably inhibited, and the obtained quantum dot light-emitting diode has good working stability and overall performance.
According to the preparation method of the quantum dot light-emitting diode, the dispersion liquid of the 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal is coated to form the electron transmission layer, the obtained electron transmission layer has fewer surface defect states and good compactness and stability, and the adverse effect on a quantum dot material is avoided when the electron transmission layer is in contact with a quantum dot light-emitting layer, so that the obtained quantum dot light-emitting diode has good working stability and overall performance.
Drawings
Fig. 1 is a schematic structural diagram of a quantum dot light emitting diode according to an embodiment of the present invention;
the figures are labeled as follows:
10-an anode layer; 20-a quantum dot light emitting layer; 30-an electron transport layer; 40-cathode layer.
Detailed Description
In order to make the objects, technical solutions and technical effects of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described, and the embodiments described below are a part of the embodiments of the present invention, but not all of the embodiments.
The embodiment of the invention provides a carrier transport material, which comprises a 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide semiconductor nanocrystal.
The metal oxide semiconductor nanocrystal in the carrier transport material provided by the embodiment of the invention can be used as a material of an electron transport layer of a quantum dot light-emitting diode in the field. In some embodiments, the molar ratio of 1,4,8, 11-tetraazacyclotetradecane to metal oxide semiconductor nanocrystal in the 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide semiconductor nanocrystal is (0.15-0.20):3, preferably 0.18: 3. If the content of 1,4,8, 11-tetraazacyclotetradecane is too low, the metal oxide semiconductor nanocrystal is difficult to be effectively and fully coordinated and modified, the passivation effect is not obvious, and the purpose of improving the performance of the device is difficult to achieve; if the content of 1,4,8, 11-tetraazacyclotetradecane is too high, it will cause difficulties in subsequent impurity treatment and cleaning, and it will easily cause a problem of poor film-forming quality of the obtained electron transport layer material.
In some embodiments, the metal oxide semiconductor nanocrystal is an undoped metal oxide semiconductor nanocrystal or a doped metal oxide semiconductor nanocrystal. Specifically, when the metal oxide semiconductor nanocrystal is an undoped metal oxide semiconductor nanocrystal, it is selected from ZnO nanocrystals, CuO nanocrystals, Cu nanocrystals2O nanocrystals, Fe3O4Nanocrystal, FeO nanocrystal, V2O5Nanocrystalline, MoO3Nanocrystalline, MnTiO3Nanocrystalline, BaTiO3Nanocrystal, HgS nanocrystal, PbS nanocrystal, SnS nanocrystal, TiO2Nanocrystalline, SnO2Nanocrystal, In2O3At least one of a nanocrystal and a NiOx nanocrystal. When the metal oxide semiconductor nanocrystal is a doped metal oxide semiconductor nanocrystal, the dopant is selected from at least one of Li, Mg, Al, Cd, In, Cu, Cs, Ga and Gd, and the doping amount of the dopant is 0.001 wt% -50 wt%.
The carrier transport material provided by the embodiment of the invention can be prepared by the following preparation method.
Correspondingly, the embodiment of the invention also provides a preparation method of the carrier transmission material, which comprises the following steps:
s1, providing metal acetate, 1,4,8, 11-tetraazacyclotetradecane, organic amine, a precipitating agent and a solvent, wherein a metal element in the metal acetate is a metal element in the metal oxide semiconductor nanocrystal;
s2, mixing metal acetate, 1,4,8, 11-tetraazacyclotetradecane, organic amine and a solvent, and carrying out hydrolysis reaction on the metal acetate to obtain a solution containing 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystals;
and S3, mixing the solution with a precipitator, and performing solid-liquid separation to obtain the solid which is the metal oxide semiconductor nanocrystal coordinated and modified by 1,4,8, 11-tetraazacyclotetradecane.
Specifically, in S1, metal acetate is used as the starting material for preparing the metal oxide moietyThe raw material of the conductor nanocrystalline is subjected to hydrolysis reaction in a Lewis alkaline environment. The metal element in the metal acetate is a metal element in a metal oxide semiconductor nanocrystal which is expected to be prepared, the metal oxide semiconductor nanocrystal comprises a material which can be used as an electron transport layer of a quantum dot light-emitting diode in the field, and specific selection of the metal element is as described above, and details are not repeated here. For example, when the desired metal oxide semiconductor nanocrystal is a ZnO nanocrystal, the metal acetate is zinc acetate (Zn (Ac)2·2H2O); when the metal oxide semiconductor nanocrystal desired to be prepared is a Mg-doped ZnO nanocrystal, the metal acetate is a mixture of magnesium acetate and zinc acetate.
In the embodiment of the invention, 1,4,8, 11-tetraazacyclotetradecane, also called cyclamine, is used as a ligand, and is subjected to coordination modification with cations on the surface of a metal oxide nanocrystal in the process of obtaining the metal oxide nanocrystal through hydrolysis reaction of metal acetate.
The organic amine is used for providing a Lewis alkaline environment in the embodiment of the invention, so that the metal acetate undergoes a hydrolysis reaction to obtain the metal oxide nanocrystal. In some embodiments, the organic amine is selected from at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide. The organic amines are relatively weak in alkalinity, and the addition of the organic amines is beneficial to slowing down the generation rate of metal hydroxide colloid, so that the metal oxide nanocrystals with relatively smaller sizes can be prepared more easily. In addition, the organic amines contain hydroxide ions and can be combined with H combined with N on the 1,4,8, 11-tetraazacyclotetradecane, so that the coordination of the 1,4,8, 11-tetraazacyclotetradecane and the metal oxide nanocrystal can be accelerated.
The precipitator is used for precipitating the metal oxide nanocrystals in the mixed solution in the embodiment of the invention so as to achieve the effect of separating from other substances. In some embodiments, the precipitating agent is selected from at least one of ethyl acetate, methyl acetate. The precipitants have extremely weak polarity, and not only can effectively dissolve unreacted precursors in the reaction process, but also can precipitate metal oxide nanocrystals.
The solvent, which is used as a dispersion medium in the present examples, is used to disperse the metal acetate, 1,4,8, 11-tetraazacyclotetradecane and/or the organic amine. In some embodiments, the solvent is selected from at least one of dimethyl sulfoxide, ethanol, butanol. Specifically, dimethyl sulfoxide (DMSO) has a good dispersing effect on metal acetate and 1,4,8, 11-tetraazacyclotetradecane, and the metal acetate and the 1,4,8, 11-tetraazacyclotetradecane can be dispersed by dimethyl sulfoxide to obtain a mixed solution of the metal acetate and the 1,4,8, 11-tetraazacyclotetradecane for later use; the ethanol and/or butanol have good dispersion effect on the organic amine, and the organic amine can be dispersed by the ethanol and/or butanol to obtain an organic amine solution for later use.
In S2, metal acetate, 1,4,8, 11-tetraazacyclotetradecane, organic amine and a solvent are mixed, wherein, in a Lewis alkaline environment provided by the organic amine, the metal acetate is subjected to hydrolysis reaction, and simultaneously, H combined with N on the 1,4,8, 11-tetraazacyclotetradecane is ionized in the hydrolysis process, so that the 1,4,8, 11-tetraazacyclotetradecane is negatively charged, and is further coordinated with cations on the surface of metal oxide nanocrystalline particles generated by the hydrolysis of the metal acetate, and the 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide semiconductor nanocrystalline is obtained. Since metal hydroxide colloid is generated during the hydrolysis reaction of metal acetate, and 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystal is gradually precipitated along with the increase of the colloid amount, in some embodiments, it is preferable to drop the solution in which organic amine is dispersed into the mixed solution in which metal acetate and 1,4,8, 11-tetraazacyclotetradecane are dispersed, which is beneficial to controlling the reaction rate and the generation of 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystal.
In some embodiments, the molar ratio of the metal acetate, 1,4,8, 11-tetraazacyclotetradecane, and organic amine is controlled to 3 (0.1-3) to (4-10), preferably 3:0.2: 6. When the molar amount of the 1,4,8, 11-tetraazacyclotetradecane serving as a ligand is too small, the ligand on the surface of the obtained metal oxide nanocrystal particle is not completely covered, and the purpose of effectively passivating the surface of the metal oxide nanocrystal cannot be achieved. When the molar amount thereof is too large, the formation rate of the metal oxide nanocrystals tends to be adversely affected. When the molar quantity of the organic amine is too small, the hydrolysis reaction of metal acetate is not facilitated, the metal hydroxide colloid is not facilitated to be separated out from the metal oxide nanocrystal, and the obtained metal oxide nanocrystal is too small; if the molar amount of the organic amine is too large, the organic amine is easily coordinated with the metal oxide nanocrystal, and 1,4,8, 11-tetraazacyclotetradecane cannot coordinate and modify the metal oxide nanocrystal as expected.
In some embodiments, after the metal acetate, the 1,4,8, 11-tetraazacyclotetradecane, the organic amine and the solvent are mixed, the metal acetate starts hydrolysis reaction, and the hydrolysis reaction temperature is controlled to be 25-60 ℃, which is beneficial to improving the rate of the hydrolysis reaction, so that the hydrolysis reaction is fully performed, and simultaneously, the generation of 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystals with uniform particles is promoted. Specifically, typical, but not limiting, hydrolysis reaction temperatures are 25 deg.C, 30 deg.C, 35 deg.C, 40 deg.C, 45 deg.C, 50 deg.C, 55 deg.C, 60 deg.C.
In some embodiments, by optimizing the temperature of the 1,4,8, 11-tetraazacyclotetradecane and the hydrolysis reaction, the control of the particle size of the obtained 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal is facilitated, and the average particle size of the 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal is preferably controlled to be 2nm-20nm, preferably 4nm-10nm, so that a compact, uniform and excellent-performance electron transport layer is formed. Specifically, typical, but not limiting, average particle diameters are 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20 nm.
In the step S3, after the hydrolysis reaction of S2 is completed, the obtained solution is a mixed solution containing the 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystal, and the 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystal is in an unseparated state. In order to separate the 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal, a precipitator is required to be added. After a precipitator is mixed with a solution containing 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal, the 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal can be separated in a precipitation form through simple solid-liquid separation. The specific method for solid-liquid separation in the embodiment of the present invention is not particularly limited, and includes, but is not limited to, filtration, centrifugation, and the like. In some embodiments, in order to improve the purity of the obtained 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal and remove impurities in the metal oxide nanocrystal as much as possible, after one solid-liquid separation, the solid precipitate is preferably dissolved by ethanol, then a precipitator is added for mixing treatment again and solid-liquid separation, and the step is repeated for 2-5 times. The 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystal obtained in the embodiment of the invention can be dispersed in ethanol and/or butanol for later use.
The embodiment of the invention also provides a quantum dot light emitting diode (QLED), which comprises an anode and a cathode which are oppositely arranged, and a quantum dot light emitting layer and an electron transmission layer which are arranged between the anode and the cathode in a laminated manner, wherein the electron transmission layer comprises the carrier transmission material provided by the embodiment of the invention, or the carrier transmission material prepared by the preparation method of the carrier transmission material provided by the embodiment of the invention.
According to the quantum dot light-emitting diode provided by the embodiment of the invention, the electron transmission layer contains the metal oxide nanocrystal coordinated and modified by 1,4,8, 11-tetraazacyclotetradecane, so that the surface defect state is less, and the quantum dot light-emitting diode has good compactness and stability. Avoid when this electron transport layer contacts with quantum dot luminescent layer causing adverse effect to the quantum dot material, reduced interface fluorescence quenching, easily cause the compound problem of non auger, but also help suppressing quantum dot emitting diode's leakage current problem, make gained quantum dot emitting diode have good job stabilization nature and overall performance.
The quantum dot light-emitting diode provided by the embodiment of the invention can be an upright quantum dot light-emitting diode or an inverted quantum dot light-emitting diode. The structure and the preparation method of the front-mounted quantum dot light-emitting diode provided by one embodiment of the present invention are described in detail below with reference to fig. 1:
a quantum dot light emitting diode comprises an anode layer 10, a quantum dot light emitting layer 20 arranged on the surface of the anode 10, an electron transmission layer 30 arranged on the surface of the quantum dot light emitting layer 20, which deviates from the anode 10, and a cathode layer 40 arranged on the surface of the electron transmission layer 30, which deviates from the quantum dot light emitting layer 20. The material for forming the electron transport layer 40 includes the metal oxide semiconductor nanocrystal coordinated and modified by 1,4,8, 11-tetraazacyclotetradecane provided by the embodiment of the invention.
Further, the quantum dot light emitting diode provided by the embodiment of the present invention further includes a hole functional layer, and the hole functional layer is disposed between the anode layer 10 and the quantum dot light emitting layer 20.
The quantum dot light-emitting diode provided by the embodiment of the invention can be prepared by the following method. The light emitting diode provided by the embodiment of the invention can be an upright light emitting diode or an inverted light emitting diode, and accordingly, the preparation method of the light emitting diode provided by the embodiment of the invention also comprises a preparation method of the upright light emitting diode (S11-S13) and a preparation method of the inverted light emitting diode (S21-S23).
Correspondingly, the embodiment of the invention also provides a preparation method of the quantum dot light-emitting diode, which comprises the following steps:
s11, providing an anode, and preparing a quantum dot light-emitting layer on the surface of the anode;
s12, providing a 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide semiconductor nanocrystal dispersion liquid, and coating the dispersion liquid on the surface of the quantum dot light-emitting layer, which is away from the anode, to obtain an electron transmission layer;
s13, preparing a cathode on the surface of the electron transmission layer, which is far away from the quantum dot light emitting layer, and obtaining the quantum dot light emitting diode;
or
S21, providing a cathode and a metal oxide semiconductor nanocrystalline dispersion liquid modified by 1,4,8, 11-tetraazacyclotetradecane coordination, and coating the dispersion liquid on the surface of the cathode to obtain an electron transport layer;
s22, preparing a quantum dot light-emitting layer on the surface of the electron transport layer, which is far away from the cathode;
and S23, preparing an anode on the surface of the quantum dot light-emitting layer, which is away from the electron transmission layer, to obtain the quantum dot light-emitting diode.
According to the preparation method of the quantum dot light-emitting diode provided by the embodiment of the invention, the electronic transmission layer is formed by coating the dispersion liquid of the 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide nanocrystal, the obtained electronic transmission layer has fewer surface defect states and good compactness and stability, and when the electronic transmission layer is in contact with the quantum dot light-emitting layer, the adverse effect on a quantum dot material is avoided, so that the obtained quantum dot light-emitting diode has good working stability and overall performance.
In S12 and S21, the metal oxide semiconductor nanocrystal dispersion liquid modified by 1,4,8, 11-tetraazacyclotetradecane coordination is a dispersion liquid obtained by dispersing the metal oxide semiconductor nanocrystal modified by 1,4,8, 11-tetraazacyclotetradecane coordination in a suitable dispersion medium. In some embodiments, the concentration of the 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide semiconductor nanocrystal in the dispersion of the 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide semiconductor nanocrystal is from 20mg/mL to 40 mg/mL.
In some embodiments, the thickness of the resulting electron transport layer of S12 and S21 is 10nm to 180nm, respectively. In particular, typical but not limiting thicknesses are 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180 nm.
In the quantum dot light-emitting diode and the preparation method thereof provided by the embodiment of the invention, except for the material of the electron transport layer, the materials for forming other layers can all adopt the conventional materials in the field, the method for forming each layer can all adopt the conventional methods in the field, and the thickness of each formed layer can all adopt the conventional thickness in the field.
In order to clearly understand the details and operation of the above embodiments of the present invention for those skilled in the art, and to obviously embody the advanced performance of the carrier transport material, the preparation method thereof, and the quantum dot light emitting diode according to the embodiments of the present invention, the above technical solutions are illustrated by a plurality of embodiments.
Example 1
The embodiment provides a preparation method of a carrier transmission material and a quantum dot light-emitting diode, which comprises the following steps:
(101) 3mmol of Zn (Ac) were weighed2·2H2Placing O and 0.15mmol of 1,4,8, 11-tetraazacyclotetradecane in a three-neck flask, adding 30ml of DMSO, and then placing at 25 ℃ to stir until the DMSO is completely dissolved to obtain a solution;
(102) dissolving 5.8mmol of tetramethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(103) slowly dropwise adding the dispersion liquid obtained in the step (102) into the solution obtained in the step (101) at room temperature to enable Zn (Ac)2·2H2Carrying out hydrolysis reaction on O, adding ethyl acetate into the obtained mixed solution for precipitation after the reaction is finished, centrifuging, and removing supernatant;
(104) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain 1,4,8, 11-tetraazacyclotetradecane coordination modified zinc oxide semiconductor nanocrystal with the average particle size of 6nm, namely the current carrier transmission material, and dispersing the current carrier transmission material in ethanol to obtain a current carrier transmission material solution with the content of the 1,4,8, 11-tetraazacyclotetradecane coordination modified zinc oxide semiconductor nanocrystal of 30mg/mL for later use;
(105) an ITO anode layer with the thickness of 70nm and PEDOT with the thickness of 30nm are sequentially deposited on a glass substrate, wherein the ITO anode layer comprises a PSS hole injection layer, a TFB hole transport layer with the thickness of 80nm and a CdZnSe/ZnSe/ZnS quantum dot light emitting layer with the thickness of 40 nm;
(106) coating the carrier transport material solution obtained in the step (104) on the surface of the quantum dot light emitting layer, which is away from the hole transport layer, and annealing to obtain an electron transport layer with the thickness of 50 nm;
(107) depositing an Al cathode with the thickness of 50nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(108) and packaging by adopting electronic packaging adhesive to obtain the quantum dot light-emitting diode.
Example 2
The embodiment provides a preparation method of a carrier transmission material and a quantum dot light-emitting diode, which comprises the following steps:
(201) 3mmol of Zn (Ac) were weighed2·2H2Placing O and 0.18mmol of 1,4,8, 11-tetraazacyclotetradecane in a three-neck flask, adding 30ml of DMSO, and then placing at 35 ℃ to stir until the DMSO is completely dissolved to obtain a solution;
(202) dissolving 5.5mmol of tetramethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(203) slowly dropwise adding the dispersion liquid obtained in the step (202) into the solution obtained in the step (201) at room temperature to enable Zn (Ac)2·2H2Carrying out hydrolysis reaction on O, adding methyl acetate into the obtained mixed solution for precipitation after the reaction is finished, centrifuging, and removing supernatant;
(204) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain 1,4,8, 11-tetraazacyclotetradecane coordination modified zinc oxide semiconductor nanocrystal with the average particle size of 6.5nm, namely the current carrier transmission material, and dispersing the current carrier transmission material in ethanol to obtain a current carrier transmission material solution with the content of the 1,4,8, 11-tetraazacyclotetradecane coordination modified zinc oxide semiconductor nanocrystal of 30mg/mL for later use;
(205) an ITO anode layer with the thickness of 80nm, PEDOT with the thickness of 50nm, a PSS hole injection layer, a TFB hole transmission layer with the thickness of 80nm and a CdZnSe/CdZnS quantum dot light-emitting layer with the thickness of 30nm are sequentially deposited on a glass substrate;
(206) coating the carrier transport material solution obtained in the step (204) on the surface of the quantum dot light emitting layer, which is away from the hole transport layer, and annealing to obtain an electron transport layer with the thickness of 40 nm;
(207) depositing an Al cathode with the thickness of 50nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(208) and packaging by adopting electronic packaging adhesive to obtain the quantum dot light-emitting diode.
Example 3
The embodiment provides a preparation method of a carrier transmission material and a quantum dot light-emitting diode, which comprises the following steps:
(301) 3mmol of Zn (Ac) were weighed2·2H2Placing O and 0.20mmol of 1,4,8, 11-tetraazacyclotetradecane in a three-neck flask, adding 35ml of DMSO, and then placing at 25 ℃ to stir until the DMSO is completely dissolved to obtain a solution;
(302) dissolving 6.0mmol of tetraethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(303) slowly dropwise adding the dispersion liquid obtained in the step (302) into the solution obtained in the step (301) at 40 ℃ to enable Zn (Ac)2·2H2Carrying out hydrolysis reaction on O, adding ethyl acetate into the obtained mixed solution for precipitation after the reaction is finished, centrifuging, and removing supernatant;
(304) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain 1,4,8, 11-tetraazacyclotetradecane coordination modified zinc oxide semiconductor nanocrystal with the average grain diameter of 5.8nm, namely the current carrier transmission material, and dispersing the current carrier transmission material in ethanol to obtain a current carrier transmission material solution with the content of the 1,4,8, 11-tetraazacyclotetradecane coordination modified zinc oxide semiconductor nanocrystal of 30mg/mL for later use;
(305) an ITO anode layer with the thickness of 80nm and PEDOT with the thickness of 60nm are sequentially deposited on a glass substrate, wherein the ITO anode layer comprises a PSS hole injection layer, a TFB hole transport layer with the thickness of 80nm and a CdZnSe/ZnSe/CdZnS quantum dot light emitting layer with the thickness of 20 nm;
(306) coating the carrier transport material solution obtained in the step (304) on the surface of the quantum dot light emitting layer, which is away from the hole transport layer, and annealing to obtain an electron transport layer with the thickness of 60 nm;
(307) depositing an Al cathode with the thickness of 50nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(308) and (5) adopting electronic packaging glue for packaging to obtain the quantum dot light-emitting diode.
Example 4
The embodiment provides a preparation method of a carrier transmission material and a quantum dot light-emitting diode, which comprises the following steps:
(401) 3mmol of Zn (Ac) were weighed2·2H2O，0.15mmol Mg(Ac)2·4H2Placing O and 0.25mmol of 1,4,8, 11-tetraazacyclotetradecane in a three-neck flask, adding 35ml of DMSO, and then placing at 25 ℃ to stir until the DMSO is completely dissolved to obtain a solution;
(402) dissolving 6.4mmol of tetramethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(403) slowly dropwise adding the dispersion liquid obtained in the step (402) into the solution obtained in the step (401) at 50 ℃ to enable Zn (Ac)2·2H2Carrying out hydrolysis reaction on O, adding methyl acetate into the obtained mixed solution for precipitation after the reaction is finished, centrifuging, and removing supernatant;
(404) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain 1,4,8, 11-tetraazacyclotetradecane coordination modified magnesium-doped zinc oxide nanocrystal with the average grain diameter of 7.0nm, namely the carrier transmission material, and dispersing the magnesium-doped zinc oxide nanocrystal in ethanol to obtain a carrier transmission material solution with the content of 1,4,8, 11-tetraazacyclotetradecane coordination modified zinc oxide semiconductor nanocrystal of 30mg/mL for later use;
(405) sequentially depositing an ITO anode layer with the thickness of 60nm, PEDOT with the thickness of 70nm, a PSS hole injection layer, a TFB hole transmission layer with the thickness of 90nm and a CdZnSe/ZnSe/CdZnS/ZnS quantum dot light-emitting layer with the thickness of 15nm on a glass substrate;
(406) coating the carrier transport material solution obtained in the step (404) on the surface of the quantum dot light emitting layer, which is away from the hole transport layer, and annealing to obtain an electron transport layer with the thickness of 60 nm;
(407) depositing an Al cathode with the thickness of 60nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(408) and packaging by adopting electronic packaging adhesive to obtain the quantum dot light-emitting diode.
Comparative example 1
The comparative example provides a method for preparing a carrier transport material and a quantum dot light emitting diode, comprising the following steps:
(501) 3mmol of Zn (Ac) were weighed2·2H2Placing O in a three-neck flask, adding 30ml of DMSO, and then placing at 25 ℃ to stir until the DMSO is completely dissolved to obtain a solution;
(502) dissolving 5.8mmol of tetramethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(503) slowly dropwise adding the dispersion liquid obtained in the step (502) into the solution obtained in the step (501) at room temperature to enable Zn (Ac)2·2H2Carrying out hydrolysis reaction on O, adding ethyl acetate into the obtained mixed solution for precipitation after the reaction is finished, centrifuging, and removing supernatant;
(504) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain zinc oxide semiconductor nanocrystals with the average particle size of 5.8nm, namely the carrier transmission material, and dispersing the zinc oxide semiconductor nanocrystals in ethanol to obtain a carrier transmission material solution with the zinc oxide semiconductor nanocrystal content of 30mg/mL for later use;
(505) sequentially depositing an ITO anode layer with the thickness of 70nm, PEDOT with the thickness of 30nm, a PSS hole injection layer, a TFB hole transmission layer with the thickness of 80nm and a CdZnSe/ZnSe/ZnS quantum dot light-emitting layer with the thickness of 40nm on a glass substrate;
(506) coating the carrier transport material solution obtained in the step (504) on the surface of the quantum dot light emitting layer, which is away from the hole transport layer, and annealing to obtain an electron transport layer with the thickness of 50 nm;
(507) depositing an Al cathode with the thickness of 50nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(508) and packaging by adopting electronic packaging adhesive to obtain the quantum dot light-emitting diode.
Comparative example 2
The comparative example provides a preparation method of a carrier transmission material and a quantum dot light-emitting diode, which comprises the following steps:
(601) 3mmol of Zn (Ac) were weighed2·2H2O in a three-neck flask, 30ml DMSO was added, and the mixture was stirred at 35 ℃ until the mixture was stirredCompletely dissolving to obtain a solution;
(602) dissolving 5.5mmol of tetramethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(603) slowly dropwise adding the dispersion liquid in the step (602) into the solution obtained in the step (601) at room temperature to ensure that Zn (Ac)2·2H2Carrying out hydrolysis reaction on the O, adding methyl acetate into the obtained mixed solution for precipitation after the reaction is finished, centrifuging and discarding the supernatant;
(604) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain zinc oxide semiconductor nanocrystals with the average particle size of 6.3nm, namely the current carrier transmission material, and dispersing the zinc oxide semiconductor nanocrystals in ethanol to obtain a current carrier transmission material solution with the zinc oxide semiconductor nanocrystal content of 30mg/mL for later use;
(605) an ITO anode layer with the thickness of 80nm, PEDOT with the thickness of 50nm, a PSS hole injection layer, a TFB hole transmission layer with the thickness of 80nm and a CdZnSe/CdZnS quantum dot light-emitting layer with the thickness of 30nm are sequentially deposited on a glass substrate;
(606) coating the carrier transport material solution obtained in the step (604) on the surface of the quantum dot light emitting layer, which is away from the hole transport layer, and annealing to obtain an electron transport layer with the thickness of 40 nm;
(607) depositing an Al cathode with the thickness of 50nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(608) and packaging by adopting electronic packaging adhesive to obtain the quantum dot light-emitting diode.
Comparative example 3
The comparative example provides a method for preparing a carrier transport material and a quantum dot light emitting diode, comprising the following steps:
(701) 3mmol of Zn (Ac) were weighed2·2H2Placing O in a three-neck flask, adding 35ml of DMSO, and then placing at 25 ℃ to stir until the DMSO is completely dissolved to obtain a solution;
(702) dissolving 6.0mmol of tetraethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(703) at 40 ℃, step (7)02) The dispersion in (3) is slowly added dropwise to the solution obtained in step (701) to cause Zn (Ac)2·2H2Carrying out hydrolysis reaction on O, adding ethyl acetate into the obtained mixed solution for precipitation after the reaction is finished, centrifuging, and removing supernatant;
(704) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain zinc oxide semiconductor nanocrystals with the average particle size of 5.6nm, namely the carrier transmission material, and dispersing the zinc oxide semiconductor nanocrystals in ethanol to obtain a carrier transmission material solution with the zinc oxide semiconductor nanocrystal content of 30mg/mL for later use;
(705) an ITO anode layer with the thickness of 80nm and PEDOT with the thickness of 60nm are sequentially deposited on a glass substrate, wherein the ITO anode layer comprises a PSS hole injection layer, a TFB hole transport layer with the thickness of 80nm and a CdZnSe/ZnSe/CdZnS quantum dot light-emitting layer with the thickness of 20 nm;
(706) coating the carrier transport material solution obtained in the step (704) on the surface of the quantum dot light emitting layer, which is away from the hole transport layer, and annealing to obtain an electron transport layer with the thickness of 60 nm;
(707) depositing an Al cathode with the thickness of 50nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(708) and packaging by adopting electronic packaging adhesive to obtain the quantum dot light-emitting diode.
Comparative example 4
The comparative example provides a method for preparing a carrier transport material and a quantum dot light emitting diode, comprising the following steps:
(801) 3mmol of Zn (Ac) were weighed2·2H2O and 0.15mmol Mg (Ac)2·4H2Placing O in a three-neck flask, adding 35ml of DMSO, and then placing at 25 ℃ to stir until the DMSO is completely dissolved to obtain a solution;
(802) dissolving 6.4mmol of tetramethylammonium hydroxide in 10ml of ethanol to obtain a dispersion liquid;
(803) slowly dropping the dispersion liquid in the step (802) into the solution obtained in the step (801) at 50 ℃ to allow Zn (Ac)2·2H2Hydrolyzing O, and mixingAdding methyl acetate into the resultant solution for precipitation, centrifuging, and removing supernatant;
(804) adding absolute ethyl alcohol into the precipitate to dissolve the precipitate, then adding ethyl acetate to precipitate, and centrifuging; repeating the step for 2-5 times to finally obtain magnesium-doped zinc oxide semiconductor nanocrystalline with the average grain diameter of 6.8nm, namely the current carrier transmission material, and dispersing the magnesium-doped zinc oxide semiconductor nanocrystalline in ethanol to obtain a current carrier transmission material solution with the content of the magnesium-doped zinc oxide semiconductor nanocrystalline of 30mg/mL for later use;
(805) an ITO anode layer with the thickness of 60nm and PEDOT with the thickness of 70nm are sequentially deposited on a glass substrate, wherein the ITO anode layer comprises a PSS hole injection layer, a TFB hole transport layer with the thickness of 90nm and a CdZnSe/ZnSe/ZnS quantum dot light emitting layer with the thickness of 15 nm;
(806) coating the carrier transmission material solution obtained in the step (804) on the surface of the quantum dot light-emitting layer, which is away from the hole transmission layer, and annealing to obtain an electron transmission layer with the thickness of 60 nm;
(807) depositing an Al cathode with the thickness of 60nm on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer;
(808) and packaging by adopting electronic packaging adhesive to obtain the quantum dot light-emitting diode.
Examples of the experiments
The quantum dot light emitting diodes obtained in test examples 1 to 4 and comparative examples 1 to 4 were subjected to performance tests according to the following methods:
(1) external quantum dot efficiency: the ratio of the number of electrons-holes injected into the quantum dots to the number of emitted photons is an important parameter for measuring the quality of the electroluminescent device, and the ratio can be obtained by adopting an EQE optical testing instrument. The specific calculation formula is as follows:
Figure BDA0002876351430000181
wherein η e is the light output coupling efficiency, η r is the ratio of the number of recombination carriers to the number of injection carriers, χ is the ratio of the number of excitons generating photons to the total number of excitons, KR is the radiative process rate, and KNR is the non-radiative process rate.
And (3) testing conditions are as follows: the method is carried out at room temperature, and the air humidity is 30-60%.
(2) Life of QLED device: the time required for the luminance of the device to decrease to a certain proportion of the maximum luminance under constant current or voltage driving, the time for the luminance to decrease to 95% of the maximum luminance is defined as T95, and the lifetime is the measured lifetime. To shorten the test period, the device lifetime test is usually performed at high luminance by accelerating device aging with reference to the OLED device test, and the lifetime at high luminance is obtained by fitting an extended exponential decay luminance fitting formula, for example: the lifetime at 1000nit is measured as T951000 nit. The specific calculation formula is as follows:
Figure BDA0002876351430000191
in the formula T95LFor lifetime at low brightness, T95HMeasured lifetime at high brightness, LHFor acceleration of the device to maximum brightness, LLThe luminance of the green QLED device is 1000nit, A is an acceleration factor, for OLED, the value is usually 1.6-2, and the value of A is 1.7 by measuring the service life of a plurality of groups of green QLED devices under rated luminance in the experiment.
And (3) testing conditions are as follows: the method is carried out at room temperature, and the air humidity is 30-60%.
The test results are shown in table 1.
TABLE 1 results of performance test of quantum dot light emitting diodes obtained in examples 1 to 4 and comparative examples 1 to 4
Name of item Example 1 Comparative example 1 Example 2 Comparative example 2 Example 3 Comparative example 3 Example 4 Comparative example 4
EQEmax(％) 15 10 14 9 16 11 16 12
T951000nit(h) 201 120 208 118 215 125 220 129
As can be seen from Table 1, the quantum dot light-emitting diode prepared by using the 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide semiconductor nanocrystal as the material of the electron transport layer has higher external quantum dot efficiency and longer device life. Therefore, the electron transmission layer is prepared by the carrier transmission material which is obtained by carrying out coordination modification on the metal oxide nanocrystal through 1,4,8, 11-tetraazacyclotetradecane, and the stability of the obtained quantum dot light-emitting diode can be improved by reducing the defect state of the surface of the metal oxide nanocrystal, so that the service life of the quantum dot light-emitting diode is prolonged; the electron transport layer is prepared from the carrier transport material which is obtained by carrying out coordination modification on the metal oxide nanocrystal by using 1,4,8, 11-tetraazacyclotetradecane, so that adverse effects on the quantum dot material can be avoided, and the obtained quantum dot light-emitting diode has better light-emitting performance.
The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed.

Claims (10)

1. The carrier transport material is characterized by comprising 1,4,8, 11-tetraazacyclotetradecane coordination modified metal oxide semiconductor nanocrystals.
2. The carrier transport material of claim 1, wherein the molar ratio of the 1,4,8, 11-tetraazacyclotetradecane to the metal oxide semiconductor nanocrystal is (0.15-0.20): 3; and/or
The metal oxide semiconductor nanocrystal is an undoped metal oxide semiconductor nanocrystal or a doped metal oxide semiconductor nanocrystal.
3. The carrier transport material of claim 2, wherein the undoped metal oxide semiconductor nanocrystals are selected from the group consisting of ZnO nanocrystals, CuO nanocrystals, Cu nanocrystals2O nanocrystals, Fe3O4Nanocrystal, FeO nanocrystal, V2O5Nanocrystalline, MoO3Nanocrystalline, MnTiO3Nanocrystalline, BaTiO3Nanocrystals, HgS nanocrystals, PbS nanocrystal, SnS nanocrystal, TiO2Nanocrystalline, SnO2Nanocrystal, In2O3At least one of a nanocrystal and a NiOx nanocrystal; and/or
The dopant In the doped metal oxide semiconductor nanocrystalline is selected from at least one of Li, Mg, Al, Cd, In, Cu, Cs, Ga and Gd, and the doping amount of the dopant is 0.001 wt% -50 wt%.
4. A preparation method of a carrier transmission material is characterized by comprising the following steps:
providing metal acetate, 1,4,8, 11-tetraazacyclotetradecane, organic amine, a precipitating agent and a solvent, wherein a metal element in the metal acetate is a metal element in a metal oxide semiconductor nanocrystal;
mixing the metal acetate, the 1,4,8, 11-tetraazacyclotetradecane, the organic amine and the solvent, and carrying out hydrolysis reaction on the metal salt to obtain a solution containing the 1,4,8, 11-tetraazacyclotetradecane coordination-modified metal oxide nanocrystal;
and mixing the solution with the precipitant, and performing solid-liquid separation to obtain the solid which is the metal oxide semiconductor nanocrystal modified by 1,4,8, 11-tetraazacyclotetradecane coordination.
5. The method for preparing a carrier transport material according to claim 4, wherein in the step of mixing the metal acetate, the 1,4,8, 11-tetraazacyclotetradecane, the organic amine and the solvent, the molar ratio of the metal acetate, the 1,4,8, 11-tetraazacyclotetradecane and the organic amine is 3 (0.1-3) to (4-10).
6. The method for preparing a carrier transport material according to claim 4, wherein the step of subjecting the metal acetate to a hydrolysis reaction is performed at a temperature of 25 ℃ to 60 ℃.
7. The method for producing a carrier transport material according to any one of claims 4 to 6, wherein the organic amine is at least one selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide and tetrabutylammonium hydroxide.
8. The method for producing the carrier transport material according to any one of claims 4 to 6, wherein the precipitant is at least one selected from the group consisting of ethyl acetate and methyl acetate; and/or
The solvent is at least one selected from dimethyl sulfoxide, ethanol and butanol.
9. A quantum dot light-emitting diode comprising an anode and a cathode which are oppositely arranged, and a quantum dot light-emitting layer and an electron transport layer which are arranged between the anode and the cathode in a laminated manner, wherein the electron transport layer comprises the carrier transport material according to any one of claims 1 to 3, or comprises the carrier transport material prepared by the method for preparing the carrier transport material according to any one of claims 4 to 9.
10. A preparation method of a quantum dot light-emitting diode is characterized by comprising the following steps:
providing an anode, and preparing a quantum dot light-emitting layer on the surface of the anode;
providing a metal oxide semiconductor nanocrystalline dispersion liquid modified by 1,4,8, 11-tetraazacyclotetradecane coordination, and coating the dispersion liquid on the surface of the quantum dot light-emitting layer, which is far away from the anode, to obtain an electron transmission layer;
preparing a cathode on the surface of the electron transmission layer, which is far away from the quantum dot light-emitting layer, so as to obtain a quantum dot light-emitting diode;
or
Providing a cathode and a metal oxide semiconductor nanocrystalline dispersion liquid modified by 1,4,8, 11-tetraazacyclotetradecane coordination, and coating the dispersion liquid on the surface of the cathode to obtain an electron transport layer;
preparing a quantum dot light-emitting layer on the surface of the electron transport layer, which is far away from the cathode;
and preparing an anode on the surface of the quantum dot light-emitting layer deviating from the electron transmission layer to obtain the quantum dot light-emitting diode.
CN202011630749.6A 2020-12-30 2020-12-30 Carrier transmission material, preparation method thereof and quantum dot light-emitting diode Pending CN114695700A (en)

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