CN116018001A

CN116018001A - Light emitting device and display panel

Info

Publication number: CN116018001A
Application number: CN202111217670.5A
Authority: CN
Inventors: 江华; 闫晓林
Original assignee: TCL Technology Group Co Ltd
Current assignee: TCL Technology Group Co Ltd
Priority date: 2021-10-19
Filing date: 2021-10-19
Publication date: 2023-04-25

Abstract

The embodiment of the invention discloses a light-emitting device and a display panel; the light-emitting device comprises an anode layer, a hole functional layer positioned on the anode layer, a light-emitting material layer positioned on the hole functional layer and a cathode layer positioned on the light-emitting material layer, wherein the hole functional layer comprises a hole functional main body material and a plurality of ZnMO nano particles which are arranged in a dispersing way, and M is any one of Al, ga, zr, mg, li; according to the embodiment of the invention, the dispersed ZnMO nano particles are arranged, so that on one hand, the ZnMO nano particles are used as electron capturing centers, the damage of excessive electrons to the hole function layer is reduced, and on the other hand, the local concentration of hole transmission is increased by adjacent ZnMO nano particles, and the radiation recombination efficiency is improved, so that the luminous efficiency of the whole luminous device is enhanced.

Description

Light emitting device and display panel

Technical Field

The invention relates to the field of display, in particular to a light-emitting device and a display panel.

Background

In recent years, the requirements on the luminous quality of the luminous device are higher and higher, and unbalanced charge injection and interface exciton quenching in the luminous device can damage a hole functional layer, so that the luminous efficiency of the whole luminous device is reduced, and the luminous quality of the luminous device is damaged.

Accordingly, a light emitting device and a display panel are needed to solve the above-mentioned problems.

Disclosure of Invention

The embodiment of the invention provides a light-emitting device and a display panel, which can solve the technical problem that the luminous efficiency of the whole light-emitting device is reduced due to the fact that a hole function layer is damaged due to unbalanced charge injection at present.

The embodiment of the invention provides a light-emitting device, which comprises an anode layer, a hole functional layer positioned on the anode layer, a light-emitting material layer positioned on the hole functional layer and a cathode layer positioned on the light-emitting material layer;

the hole functional layer comprises a hole functional main body material and a plurality of ZnMO nano particles which are arranged in a dispersing mode, wherein M is any one of Al, ga, zr, mg, li.

In an embodiment, the ZnMO nanoparticles are dispersed in the hole-functional host material, and the concentration of the ZnMO nanoparticles gradually increases in a direction approaching the light-emitting material layer.

In one embodiment, the ZnMO nanoparticles are arranged in a single layer spacing.

In an embodiment, the ZnMO nanoparticles are located between the hole-functional host material and the luminescent material layer, the ZnMO nanoparticles being arranged in a single layer at intervals.

In one embodiment, the ZnMO nanoparticles have a diameter of 2 nm to 8 nm.

In an embodiment, the band gap width of the ZnMO nanoparticles is greater than 3eV and the spacing between at least two adjacent ZnMO nanoparticles is from 0.1 nm to 20 nm.

In one embodiment, the thickness of the hole function layer is 25 nm to 35nm; in the hole functional layer, the mass ratio of M in the ZnMO nano particle is 13-27%.

In an embodiment, the light emitting device further includes an electron transport layer located on a side of the light emitting material layer away from the hole function layer, where the electron transport layer includes an electron transport host material and ZnMO nanoparticles disposed in a dispersed manner, and M is any one of Al, ga, zr, mg, li.

In one embodiment, in the electron transport layer, the mass ratio of M in the ZnMO nanoparticles is 7% to 12%; in the hole functional layer, the mass ratio of M in the ZnMO nano particle is 23-27%.

In an embodiment, the light emitting device further comprises an electron transport layer between the cathode layer and the light emitting material layer, an electron injection layer between the electron transport layer and the cathode layer, and a hole injection layer between the hole function layer and the anode layer; and/or the material of the luminescent material layer is a quantum dot, and the quantum dot comprises any one of CdSe/CdS, cdSe/ZnSe/ZnS, cdZnSe/ZnSe/ZnS and InP/ZnS.

The embodiment of the invention also provides a display panel which comprises the light-emitting device and the array substrate.

According to the embodiment of the invention, the dispersed ZnMO nano particles are arranged, so that on one hand, the ZnMO nano particles are used as electron capturing centers, the damage of excessive electrons to the hole function layer is reduced, and on the other hand, the local concentration of hole transmission is increased by adjacent ZnMO nano particles, and the radiation recombination efficiency is improved, so that the luminous efficiency of the whole luminous device is enhanced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a first structure of a light emitting device provided in an embodiment of the present invention;

fig. 2 is a schematic structural view of a second structure of a light emitting device according to an embodiment of the present invention;

fig. 3 is a schematic structural view of a third structure of a light emitting device according to an embodiment of the present invention;

fig. 4 is a schematic structural view of a fourth structure of a light emitting device provided in an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a light emitting device according to an embodiment of the present invention;

fig. 6 is a flowchart of steps in a method for manufacturing a light emitting device according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a display panel according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a mobile terminal according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention. Furthermore, it should be understood that the detailed description is presented herein for purposes of illustration and description only, and is not intended to limit the invention. In the present invention, unless otherwise indicated, terms of orientation such as "upper" and "lower" are used to generally refer to the upper and lower positions of the device in actual use or operation, and specifically the orientation of the drawing figures; while "inner" and "outer" are for the outline of the device.

Referring to fig. 1 and 5, an embodiment of the present invention provides a light emitting device 100, which includes an anode layer 200, a hole function layer 400 on the anode layer 200, a light emitting material layer 500 on the hole function layer 400, and a cathode layer 800 on the light emitting material layer 500;

the hole function layer 400 includes a hole function host material 410 and a plurality of ZnMO nanoparticles dispersed therein, where M is any one of Al, ga, zr, mg, li.

According to the embodiment of the invention, the dispersed ZnMO nano particles are arranged in the hole functional layer, can be dispersed in the hole functional main body material and can also be dispersed between the hole functional main body material and the luminescent material layer, when electrons are transmitted to the vicinity of the ZnMO nano particles through the cathode layer and the luminescent material layer, the ZnMO nano particles are introduced to serve as electron capture centers and have high electron transmission potential barriers, excessive electrons are limited in the ZnMO nano particles, on one hand, the ZnMO nano particles serve as electron capture centers, the damage of excessive electrons to the hole functional layer is reduced, and on the other hand, the adjacent ZnMO nano particles increase the local concentration of hole transmission, and the radiation recombination efficiency is improved, so that the luminous efficiency of the whole luminescent device is enhanced.

The technical scheme of the present invention will now be described with reference to specific embodiments.

Referring to fig. 1 specifically, in the present embodiment, the light emitting device 100 includes an anode layer 200, a hole function layer 400 located on the anode layer 200, a light emitting material layer 500 located on the hole function layer 400, and a cathode layer 800 located on the light emitting material layer 500; the hole function layer 400 includes a hole function host material 410 and a plurality of ZnMO nanoparticles dispersed therein, where M is any one of Al, ga, zr, mg, li.

Referring specifically to fig. 1, in some embodiments, the light emitting device 100 further includes an electron transport layer 600 between the light emitting material layer 500 and the cathode layer 800, and an electron injection layer 700 between the electron transport layer 600 and the cathode layer 800.

In some embodiments, the ZnMO nanoparticle may include only one compound, such as ZnMgO, or may include two or more compounds, such as ZnMgO and ZnLiO.

In some embodiments, the material of the luminescent material layer 500 is a quantum dot, and the quantum dot includes any one of CdSe/CdS, cdSe/ZnSe/ZnS, cdZnSe/ZnSe/ZnS, inP/ZnS. Wherein "/" indicates a core-shell structure, the first compound is a core, and the other compounds are shells, e.g. "CdSe/CdS", "CdSe" indicates a core, and "CdS" indicates a shell; "CdSe/ZnSe/ZnS", "CdSe" means a core, "ZnSe" means a first shell, "ZnS" means a second shell, and the second shell surrounds the first shell.

In some embodiments, the hole-functional host material 410 may be a hole-injecting host material or/and a hole-transporting host material, and when the hole-functional host material 410 is a hole-injecting host material and a hole-transporting host material, the hole-transporting host material is located between the hole-injecting host material and the light-emitting material layer 500.

Referring specifically to fig. 1 and 4, in some embodiments, the ZnMO nanoparticle may be mixed with the hole-functional host material 410, and the ZnMO nanoparticle may also be located between the hole-functional host material 410 and the light-emitting material layer 500, and referring specifically to fig. 5, when the electron transport reaches the vicinity of the ZnMO nanoparticle, since the ZnMO nanoparticle is introduced as an electron trapping center and has a high electron transport barrier, excessive electrons will be confined in the ZnMO nanoparticle; when the hole transport reaches the vicinity of the ZnMO nanoparticles, the high hole transport barrier will block the straight line transport of holes, and pass between two adjacent ZnMO nanoparticles, so that the local concentration of holes can be increased, which is beneficial to improving the radiative recombination efficiency of electron holes in the luminescent material layer 500, HTL represents the hole functional layer 400, etl represents the electron transport layer 600, htmm represents the hole functional host material 410, nps represents nanoparticles, and QDs represents the luminescent material layer 500.

In fig. 1 to 4, the ZnMO nanoparticles in the hole-functional layer 400 are denoted by "p", and the ZnMO nanoparticles in the electron-transporting layer 600 are denoted by "q".

Referring specifically to fig. 2, in some embodiments, the concentration of ZnMO nanoparticles increases gradually in a direction toward the luminescent material layer 500. The closer the ZnMO nanoparticles are to the direction of the luminescent material layer 500, the stronger the blocking effect on electrons emitted from one side of the electron transport layer 600, the better the protection of the hole functional layer 400, avoiding the damage of the hole functional layer 400, and enhancing the luminescent efficiency of the overall luminescent device 100.

Referring specifically to fig. 3, in some embodiments, the ZnMO nanoparticles are distributed in the hole-functional host material 410, and the ZnMO nanoparticles are arranged at intervals of a single layer, that is, the ZnMO nanoparticles distributed in the host material are concentrated on a side close to the luminescent material layer 500, so as to further enhance the capability of blocking excessive electrons.

Referring specifically to fig. 4, in some embodiments, the ZnMO nanoparticles are located between the hole-functional host material 410 and the luminescent material layer 500, and the ZnMO nanoparticles are arranged at intervals of a single layer. The hole function main body material 410 forms a hole function main body material layer, the ZnMO nanoparticles are located between the hole function main body material layer and the luminescent material layer 500, the ZnMO nanoparticles are distributed at intervals in a single layer, that is, a plurality of ZnMO nanoparticles are arranged into one layer, two adjacent ZnMO nanoparticles are arranged at intervals, gaps exist between two adjacent ZnMO nanoparticles, in the figure, the hole function main body material 410 is used for representing the hole function main body material layer, the ZnMO nanoparticles are arranged in a single layer array, and the gaps between the ZnMO nanoparticles are used for blocking redundant electrons, so that the hole function main body material layer is better protected, the hole function layer 400 is better protected, the damage of the hole function layer 400 is avoided, and the luminous efficiency of the whole luminescent device 100 is enhanced.

In some embodiments, the ZnMO nanoparticles have a diameter of 2 nm to 8 nm. The diameter of the ZnMO nanoparticle is not too small, which causes an increase in manufacturing difficulty, increases manufacturing cost, and causes a decrease in luminous efficiency of the light emitting device 100 due to incapability of passing normal electrons and holes.

In some embodiments, the ZnMO nanoparticles have a diameter of 3 nm to 5 nm. The ZnMO nanoparticles in this diameter range can both block excess electrons and increase the local transport concentration of holes, thereby maximizing the luminous efficiency of the overall light-emitting device 100.

In some embodiments, the band gap width of the ZnMO nanoparticles is greater than 3eV and the spacing between at least two adjacent ZnMO nanoparticles is from 0.1 nm to 20 nm.

In the production, the distance between two adjacent ZnMO nanoparticles can be limited by diluting the concentration of the ZnMO nanoparticles and increasing the rotation speed of spin coating, but in the practical case, the distance between two adjacent ZnMO nanoparticles is not in the range with a very small probability, so that it is understood that the distance between at least two ZnMO nanoparticles is limited to 0.1-20 nanometers when the protection range is limited, and the description is given.

The band gap width of the ZnMO nano-particles is set to be larger, so that the blocking effect on redundant electrons can be enhanced, and the recombination probability of electron holes at the hole functional layer 400 and the ZnMO nano-particles is reduced; defining the spacing between two adjacent ZnMO nanoparticles can increase the local transport concentration of holes, enhancing the light-emitting efficiency of the overall light-emitting device 100.

In some embodiments, the spacing between adjacent two of the ZnMO nanoparticles is from 3 nm to 5 nm. The preferred diameter of the ZnMO nanoparticle corresponds to the distance between two adjacent ZnMO nanoparticles, which can both block redundant electrons and increase the local transport concentration of holes, thereby maximally improving the light-emitting efficiency of the overall light-emitting device 100.

In some embodiments, the thickness of the hole function layer 400 is 25 nm to 35nm; in the hole function layer 400, the mass ratio of M in the ZnMO nanoparticle is 13% to 27%. M is taken as a doping particle to enter ZnO, M can be taken as a ligand to jointly form ZnMO nano particles, the impurity difference of M also influences the adjustment of the ZnMO nano particles on electron blocking and hole local concentration, and the specific doping effect characterization is shown in the experimental results below.

Referring specifically to fig. 3, in some embodiments, the light emitting device 100 further includes an electron transport layer 600 located on a side of the light emitting material layer 500 away from the hole function layer 400, where the electron transport layer 600 includes an electron transport host material and ZnMO nanoparticles disposed in a dispersed manner, and M is any one of Al, ga, zr, mg, li. By adding ZnMO nanoparticles to the electron transport layer 600, the local injection concentration of electrons can be increased, so that electrons can be conveniently injected into the light emitting material layer 500.

In some embodiments, in the electron transport layer 600, the mass fraction of M in the ZnMO nanoparticles is 7% to 12%; in the hole function layer 400, the mass ratio of M in the ZnMO nanoparticle is 23% to 27%. Different doping ratios of M in the ZnMO nano-particles in the electron transport layer 600 and the hole functional layer 400 are set, so that damage to the hole functional layer 400 and local injection concentration adjustment of electrons are reduced in a balanced manner, and the luminous efficiency and the service life are balanced.

In some embodiments, the hole transporting host material may be an organic material or an inorganic material, and the organic material may be any one or more of 9, 9-dioctylfluorene/N- (4-sec-butylphenyl) -diphenylamine alternating copolymer (TFB), polytrianiline, N '-bis (1-naphthyl) -N, N' -diphenyl- (1, 1 '-biphenyl) -4,4' -diamine (NPB). The inorganic material may include copper oxide (Cu ₂ O) or copper gallium oxide nanoparticles (CuxGa 1-xO).

In some embodiments, since the hole transport host material is closer to the light emitting material layer 500 than the hole injection host material, the ZnMO nanoparticles are dispersed in the hole transport host material, which may block electrons earlier, and the ZnMO nanoparticles are dispersed in the hole transport host material more effectively than in the hole injection host material.

In some embodiments, the electron transport host material may be ZnO, tiO ₂ And SnO ₂ A metal oxide semiconductor with an equal-width forbidden band.

In some embodiments, the material of the anode layer 200 may include any one or more of indium tin oxide, fluorine doped tin oxide, indium zinc oxide, graphene, and carbon nanotubes; the hole injection host material may include PEDOT: PSS, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, copper oxide. The material of the cathode layer 800 may include any one or more of indium tin oxide, al, ca, ba, ag.

In some embodiments, the material of the light emitting material layer 500 may include any one or more of nanocrystals of II-VI semiconductors, nanocrystals of III-V semiconductors, II-V compounds, III-VI compounds, IV-VI compounds, I-III-VI compounds, II-IV-VI compounds, and IV simple substances.

In some embodiments, M in the ZnMO nanoparticle may be any one or a combination of more than one of Al, ga, zr, mg, li in the electron transport layer 600 or/and the hole functional layer 400.

Referring to fig. 6, an embodiment of the present invention further provides a method for manufacturing a light emitting device 100, including:

s100, forming an anode layer 200 on the substrate.

S200, forming a hole function layer 400 including a hole function host material 410 and a plurality of ZnMO nanoparticles dispersed on the anode layer 200.

S300, forming a luminescent material layer 500 on the hole function layer 400.

S400, an electron transport layer 600 is formed on the luminescent material layer 500.

S500, a cathode layer 800 is formed on the electron transport layer 600.

S100, forming an anode layer 200 on the substrate.

Step S200 may include:

s201, forming a hole injection layer on the anode layer 200.

In some embodiments, the ZnMO nanoparticles are dispersed in a hole transport host material, and step S201 further includes:

s210a, coating a first mixture including a hole function host material 410, a first solvent, znMO nanoparticles on the hole injection layer.

In some embodiments, the hole-functional host material 410 is a hole-transporting host material, as will be exemplified below.

In some embodiments, the first solvent may be an aromatic hydrocarbon compound, such as chlorobenzene, and the ZnMO nanoparticles of the alcohol ligand are dissolved in chlorobenzene, and the spin coating of the chlorobenzene solvent and the organic hole function layer 400 is better, and the spin coating of the subsequent luminescent material layer 500 is not affected.

In some embodiments, znMO nanoparticles in the light emitting device 100 completed with step S210a are dispersed within the hole functional host material 410.

In some embodiments, taking the ZnMO nanoparticles on the hole-functional host material 410 as an example, step S201 further includes:

s210b, coating a second mixture including the hole function host material 410 and the first solvent on the hole injection layer.

S220b coating a third mixture comprising a plurality of ZnMO nanoparticles, a third solvent on the second mixture.

In some embodiments, the second solvent and/or the third solvent may be an aromatic hydrocarbon compound, such as chlorobenzene, and the ZnMO nanoparticles of the alcohol ligand are dissolved in chlorobenzene, and the chlorobenzene solvent has better spin-coating tilting property with the organic hole function layer 400, and does not affect the spin-coating of the subsequent luminescent material layer 500.

In some embodiments, the ZnMO nanoparticles in the light emitting device 100 completed with steps S210b, S220b are located between the hole-functional host material 410 and the subsequently formed light emitting material layer 500.

In some embodiments, the ZnMO nanoparticles between the hole-functional host material 410 and the luminescent material layer 500 can be provided in a single layer spaced apart arrangement by diluting the concentration of the ZnMO nanoparticles in the third mixture and increasing the spin-coating speed.

S300, forming a luminescent material layer 500 on the hole function layer 400.

In some embodiments, step S300 includes:

s310, a light emitting material and a solvent are formed on the hole function layer 400.

S320, baking the light emitting device 100.

In some embodiments, in step S320, the solvents in step S200 and step S300 may be volatilized in one step, or the solvents in step S200 may be baked in each of the steps S200.

S5400, an electron transport layer 600 is formed on the light emitting material layer 500.

In some embodiments, step S400 includes:

s410, coating a fourth mixture including an electron transport host material, a third solvent, znMO nanoparticles on the luminescent material layer 500.

S420, baking the light emitting device 100.

S500, a cathode layer 800 is formed on the electron transport layer 600.

In some embodiments, step S500 includes:

s510, an electron injection layer 700 is formed on the electron transport layer 600.

S520, a cathode layer 800 is formed on the electron injection layer 700.

In the formation process of the ZnMO nano-particles, the doping treatment is generally carried out on ZnO by using M element, so that the doping proportion of M in the ZnMO nano-particles can be controlled.

In some embodiments, 8 sets of experiments were performed for efficacy verification. Where NPs represent nanoparticles, QDs represent luminescent material layer 500, and steps are combined and simplified.

Group 1: step 1, depositing a layer of ITO on a substrate by a PVD method, then spin-coating PEDOT PSS material with the thickness of 40nm in sequence by a spin-coating method, and spin-coating TFB material with the thickness of 30nm; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 15 percent of doped Mg, the ZnMO NPs solution is taken to be dissolved in chlorobenzene with the same volume, the solution is spin-coated on the film layer in the step 1 by a spin-coating method, the spin-coating speed is 1000r/s, and the spin-coating time is 15s; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 10 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

Group 2: step 1, depositing a layer of ITO on a substrate by a PVD method, then spin-coating PEDOT PSS material with the thickness of 40nm in sequence by a spin-coating method, and spin-coating TFB material with the thickness of 30nm; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 15 percent of doped Mg, the ZnMO NPs solution is taken to be dissolved in chlorobenzene with the same volume, the solution is spin-coated on the film layer in the step 1 by a spin-coating method, the spin-coating speed is 1000r/s, and the spin-coating time is 15s; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 15 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

Group 3: step 1, depositing a layer of ITO on a substrate by a PVD method, then spin-coating PEDOT PSS material with the thickness of 40nm in sequence by a spin-coating method, and spin-coating TFB material with the thickness of 30nm; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 25 percent of doped Mg, the ZnMO NPs solution is taken to be dissolved in chlorobenzene with the same volume, the solution is spin-coated on the film layer in the step 1 by a spin-coating method, the spin-coating speed is 1000r/s, and the spin-coating time is 15s; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 10 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

Group 4: step 1, depositing a layer of ITO on a substrate by a PVD method, then spin-coating PEDOT PSS material with the thickness of 40nm in sequence by a spin-coating method, and spin-coating TFB material with the thickness of 30nm; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 25 percent of doped Mg, the ZnMO NPs solution is taken to be dissolved in chlorobenzene with the same volume, the solution is spin-coated on the film layer in the step 1 by a spin-coating method, the spin-coating speed is 1000r/s, and the spin-coating time is 15s; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 15 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

Group 5: step 1, depositing a layer of ITO on a substrate by a PVD method, and then sequentially spin-coating PEDOT (pulse-width modulation) PSS material with the thickness of 40nm by a spin-coating method; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 15 percent of doped Mg, 1 volume of the ZnMO NPs solution is taken to be dissolved in 10 volumes of TFB solution, and the solution is spin-coated on the film layer in the step 1 by a spin-coating method, wherein the thickness is 30nm; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 10 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

Group 6: step 1, depositing a layer of ITO on a substrate by a PVD method, and then sequentially spin-coating PEDOT (pulse-width modulation) PSS material with the thickness of 40nm by a spin-coating method; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 15 percent of doped Mg, 1 volume of the ZnMO NPs solution is taken to be dissolved in 10 volumes of TFB solution, and the solution is spin-coated on the film layer in the step 1 by a spin-coating method, wherein the thickness is 30nm; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 15 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

Group 7: step 1, depositing a layer of ITO on a substrate by a PVD method, and then sequentially spin-coating PEDOT (pulse-width modulation) PSS material with the thickness of 40nm by a spin-coating method; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 25 percent of doped Mg, 1 volume of the ZnMO NPs solution is taken to be dissolved in 10 volumes of TFB solution, and the solution is spin-coated on the film layer in the step 1 by a spin-coating method, wherein the thickness is 30nm; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 10 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

Group 8: step 1, depositing a layer of ITO on a substrate by a PVD method, and then sequentially spin-coating PEDOT (pulse-width modulation) PSS material with the thickness of 40nm by a spin-coating method; step 2, znMO adopts a ZnMO NPs solution with the concentration of 3Mg/ml and 25 percent of doped Mg, 1 volume of the ZnMO NPs solution is taken to be dissolved in 10 volumes of TFB solution, and the solution is spin-coated on the film layer in the step 1 by a spin-coating method, wherein the thickness is 30nm; step 3, forming a film by adopting a spin coating method, wherein the spin coating speed is 2000r/min, the spin coating time is 15s, and after the spin coating is finished, the sample is baked for 6min at 80 ℃; the electron transport layer 600 adopts 30Mg/ml ZnMO NPs solution with 15 percent of doped Mg, adopts a spin coating method to form a film, and has the spin coating thickness of 35nm; and 4, finally, depositing a layer of Ag by a PVD method, wherein the thickness is 100nm.

And comparing different doping contents, taking Mg as an example of doping particles, wherein only the ZnMO nanoparticles are located between the hole-functional host material 410 and the luminescent material layer 500, the ZnMO nanoparticles are arranged at a single-layer interval as an example, HTL represents the hole-functional layer 400, etl represents the electron-transport layer 600, HTMM represents the hole-functional host material 410, "htmm+znmo-free nanoparticles" represents that HTMM is used alone, znMO nanoparticles are not added, EQE represents external quantum efficiency, LT represents the time elapsed for the 1000nits brightness to decrease to 95%, and the following table is listed:

it can be seen that for the HTL, the overall light emitting device 100 has higher light emitting efficiency but a smaller light emitting lifetime when ZnMO nanoparticles are not added; with the addition of ZnO nano-particles, the luminous efficiency and the service life are drastically reduced; however, as the doping ratio is increased, the luminous efficiency is improved and the service life is prolonged.

For ETL, although the light emitting efficiency decreases and the service life decreases with increasing doping ratio, experimental study shows that adding ZnMO nanoparticles into ETL can improve electron injection efficiency, so that electrons are easier to be injected and transported to the luminescent material layer 500, so that the addition of ZnMO nanoparticles into ETL is needed for adjustment.

Referring to fig. 7, the embodiment of the invention further provides a display panel 10 including the light emitting device 100 and the array substrate 20 as described above.

The specific structure of the light emitting device 100 is shown in any of the embodiments of the light emitting device 100 and fig. 1 to 5, and will not be described herein.

Referring to fig. 8, an embodiment of the present invention further provides a mobile terminal 1, including any one of the display panels 10 and the terminal body 2, wherein the terminal body 2 and the display panel 10 are combined into a whole.

In this embodiment, the terminal body 2 may include a middle frame, a frame glue, etc., and the mobile terminal 1 may be a mobile display terminal such as a mobile phone, a tablet, etc., which is not limited herein.

The above description has been made in detail on a light emitting device and a display panel provided by the embodiments of the present invention, and specific examples are applied herein to illustrate the principles and embodiments of the present invention, the above description of the embodiments is only for helping to understand the method and core ideas of the present invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in light of the ideas of the present invention, the present description should not be construed as limiting the present invention.

Claims

1. A light emitting device comprising an anode layer, a hole function layer on the anode layer, a light emitting material layer on the hole function layer, and a cathode layer on the light emitting material layer;

2. The light-emitting device according to claim 1, wherein the ZnMO nanoparticles are dispersed in the hole-functional host material, and the concentration of the ZnMO nanoparticles gradually increases in a direction approaching the light-emitting material layer.

3. The light emitting device of claim 2, wherein the ZnMO nanoparticles are arranged in a single layer spaced apart.

4. The light emitting device of claim 1, wherein the ZnMO nanoparticles are located between the hole-functional host material and the light emitting material layer, the ZnMO nanoparticles being arranged in a single layer spaced apart.

5. The light emitting device of claim 1, wherein the ZnMO nanoparticles have a diameter of 2 nm to 8 nm.

6. The light emitting device of claim 1, wherein the ZnMO nanoparticles have a band gap width greater than 3eV and a spacing between at least two adjacent ZnMO nanoparticles is between 0.1 nm and 20 nm.

7. The light-emitting device according to claim 1, wherein a thickness of the hole function layer is 25 nm to 35nm;

in the hole functional layer, the mass ratio of M in the ZnMO nano particle is 13-27%.

8. The light-emitting device according to claim 1, further comprising an electron transport layer on a side of the light-emitting material layer away from the hole-function layer, wherein the electron transport layer comprises an electron transport host material and ZnMO nanoparticles dispersed therein, and M is any one of Al, ga, zr, mg, li.

9. The light-emitting device according to claim 8, wherein in the electron transport layer, the mass ratio of M in the ZnMO nanoparticle is 7% to 12%;

in the hole functional layer, the mass ratio of M in the ZnMO nano particle is 23-27%.

10. The light-emitting device according to claim 1, further comprising an electron transport layer between the cathode layer and the light-emitting material layer, an electron injection layer between the electron transport layer and the cathode layer, and a hole injection layer between the hole function layer and the anode layer;

and/or the material of the luminescent material layer is a quantum dot, and the quantum dot comprises any one of CdSe/CdS, cdSe/ZnSe/ZnS, cdZnSe/ZnSe/ZnS and InP/ZnS.

11. A display panel comprising the light-emitting device according to any one of claims 1 to 10 and an array substrate.