CN115589742A

CN115589742A - Light-emitting device, preparation method thereof and display panel

Info

Publication number: CN115589742A
Application number: CN202110761162.7A
Authority: CN
Inventors: 田鹍飞
Original assignee: TCL Technology Group Co Ltd
Current assignee: TCL Technology Group Co Ltd
Priority date: 2021-07-06
Filing date: 2021-07-06
Publication date: 2023-01-10

Abstract

The application discloses a light-emitting device, a preparation method thereof and a display panel. In the application, the protective layer is formed by adopting the P-type black phosphorus, so that the energy band of the hole transport layer is matched with the energy bands of the hole injection layer and the light-emitting layer, the injection of carriers is balanced, and the light-emitting efficiency of the light-emitting device is improved.

Description

Light-emitting device, preparation method thereof and display panel

Technical Field

The application relates to the technical field of display, in particular to a light-emitting device, a preparation method thereof and a display panel.

Background

The quantum dot electroluminescent diode has wide application prospect in display due to high luminescent color purity, adjustable luminescent wavelength and solution-soluble processing characteristic.

At present, in a quantum dot electroluminescent diode device, a substrate, an anode, a hole injection layer, a hole transport layer, a quantum dot light emitting layer, an electron transport layer, an electron injection layer, and a cathode are generally stacked from bottom to top. However, the energy level mismatch between the hole injection layer and the hole transport layer causes carrier injection imbalance, which in turn causes unstable performance of the light emitting device.

Disclosure of Invention

The embodiment of the application provides a light-emitting device, a preparation method thereof and a display panel, so as to solve the problem of carrier injection imbalance.

The embodiment of the application provides a light-emitting device, including protective layer, hole injection layer and hole transport layer, the protective layer with hole transport layer all set up in on the hole injection layer, the material of protective layer includes P type black phosphorus.

Optionally, in some embodiments of the present application, the material of the protective layer further includes an additional material, the additional material coats the P-type black phosphorus to form a core-shell material, and the additional material is selected from one or a combination of dodecylbenzene sulfonate, polyvinylpyrrolidone, oleylamine, oleic acid, trioctylphosphine oxide, octadecylphosphonic acid, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,4-benzenedithiol, 1,2-hexadecanediol, 1,7-diaminopentane, 1,4-diaminobenzene, and tetradecylphosphonic acid.

Optionally, in some embodiments of the present application, the protection layer includes a first protection portion, and the first protection portion and the hole transport layer are sequentially stacked on the hole injection layer.

Optionally, in some embodiments of the present application, the protection layer includes a second protection portion, and the hole transport layer and the second protection portion are sequentially stacked on the hole injection layer.

Optionally, in some embodiments of the present application, the protection layer includes a first protection portion and a second protection portion, and the first protection portion, the hole transport layer, and the second protection portion are sequentially stacked on the hole injection layer.

Optionally, in some embodiments of the present application, the number of layers of the P-type black phosphorus is 1 to 10, and the lateral size of the P-type black phosphorus is 1 nm to 10 μm.

Optionally, in some embodiments of the present application, the number of layers of the P-type black phosphorus is 10 to 20, and the lateral size of the P-type black phosphorus is 10 to 100 micrometers.

Optionally, in some embodiments of the present application, the light emitting device further includes a light emitting layer, a first electrode, and a second electrode, the hole injection layer is disposed on the first electrode, the protective layer and the hole transport layer are both disposed between the light emitting layer and the hole injection layer, and the second electrode is disposed on the light emitting layer.

The application also provides a preparation method of the light-emitting device, which comprises a step of forming a protective layer, a step of forming a hole injection layer and a step of forming a hole transport layer, wherein the protective layer is made of P-type black phosphorus.

Optionally, in some embodiments of the present application, the step of forming the protective layer includes:

providing additional materials, wherein the additional materials react with the P-type black phosphorus to form a core-shell material, and the additional materials are selected from one or a combination of dodecyl benzene sulfonate, polyvinylpyrrolidone, oleylamine, oleic acid, trioctylphosphine oxide, octadecylphosphonic acid, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,4-benzenedithiol, 1,2-hexadecanediol, 1,7-diaminopentane, 1,4-diaminobenzene and tetradecylphosphonic acid.

arranging the core-shell material on the hole injection layer to form a first protection part of the protection layer;

a hole transport layer is formed on the first protective portion.

forming a hole transport layer over the hole injection layer;

and arranging the core-shell material on the hole transport layer to form a second protection part of the protection layer.

forming a hole transport layer on the first protective portion;

The application also provides a display panel, which comprises the light-emitting device or the light-emitting device prepared by the preparation method.

The application discloses a light-emitting device, a preparation method thereof and a display panel. In the application, the protective layer is formed by adopting the P-type black phosphorus, because the P-type black phosphorus is a material of which the band gap can be adjusted by adjusting the thickness, when the protective layer is arranged between the hole injection layer and the hole transport layer and/or between the hole transport layer and the light-emitting layer, a new energy level gradient can be introduced between the hole injection layer and the hole transport layer and/or between the hole transport layer and the light-emitting layer, and because the P-type black phosphorus has adjustable band gap property, the transmission of holes is facilitated, the recombination of electrons and holes is inhibited, namely, the injection of carriers is balanced, and the potential barrier between the hole injection layer and the hole transport layer and/or between the hole transport layer and the light-emitting layer can be effectively reduced, so that the light-emitting efficiency of the light-emitting device is improved. Adopt P type black phosphorus to form the protective layer, P type black phosphorus is low dimension P type black phosphorus, low dimension P type black phosphorus has big specific surface area and flexibility, low dimension P type black phosphorus is from blocky its tension of thin layer and also follows the change, consequently, adjust its thickness and can adjust the stress between hole injection layer and the hole transport layer and/or between hole transport layer and the luminescent layer, and then improve the contact performance between hole injection layer and the hole transport layer and/or between hole transport layer and the luminescent layer, and can promote the linking between the different rete interfaces. The protective layer is formed by adopting the P-type black phosphorus, the P-type black phosphorus is the low-dimensional P-type black phosphorus, and the low-dimensional P-type black phosphorus has adjustable band gap property, so that the low-dimensional P-type black phosphorus has good current saturation performance, high carrier mobility and current modulation capability, and very high circuit leakage current modulation rate, and thus the light-emitting device can be effectively protected, the inactivation of the light-emitting device is avoided, and the performance of the light-emitting device is improved. The protective layer is formed by adopting P-type black phosphorus, the P-type black phosphorus is low-dimensional P-type black phosphorus, and the low-dimensional P-type black phosphorus can reduce the surface energy, so that the stress between the hole injection layer and the hole transport layer and/or the stress between the hole transport layer and the light-emitting layer interface can be reduced, the spreading degree of the film layer of the light-emitting device is improved, and the interface contact between the light-emitting layer and the hole transport layer is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

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

Fig. 2 is a schematic diagram of a second structure of a light emitting device provided in an embodiment of the present application.

Fig. 3 is a schematic view of a third structure of a light emitting device provided in an embodiment of the present application.

Fig. 4 is a schematic diagram of a fourth structure of a light emitting device provided in an embodiment of the present application.

Fig. 5 is a flowchart of a method for manufacturing a light emitting device according to an embodiment of the present disclosure.

Fig. 6 is a current density-voltage curve of a light emitting device provided in an embodiment of the present application.

Fig. 7 is a bar graph of external quantum efficiency over time for a light emitting device provided by an embodiment of the present application.

Fig. 8 is a bar graph of external quantum efficiency over time for a first prior art light emitting device.

Fig. 9 is a bar graph of external quantum efficiency over time for a second prior art light emitting device.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. Furthermore, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present application, are given by way of illustration and explanation only, and are not intended to limit the present application. In the present application, unless indicated to the contrary, the use of the directional terms "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, and more particularly to the orientation of the figures of the drawings; while "inner" and "outer" are with respect to the outline of the device. In addition, "reaction" in the present application may refer to a physical reaction or a chemical reaction.

The embodiment of the application provides a light-emitting device and a preparation method thereof. The following are detailed below. It should be noted that the following description of the embodiments is not intended to limit the preferred order of the embodiments.

Referring to fig. 1, fig. 1 is a schematic view of a first structure of a light emitting device according to an embodiment of the present disclosure. The present application provides a light emitting device 10. The light emitting device 10 includes a hole injection layer 100, a hole transport layer 200, a protective layer 290, and a light emitting layer 300. In the present embodiment, the light emitting device 10 is a front light emitting device. The specific description is as follows:

in an embodiment, the light emitting device 10 further comprises a substrate 400. The substrate 400 may be a rigid substrate or a flexible substrate. The rigid substrate may be a glass substrate. The material of the flexible substrate comprises one or a combination of several of polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone and polyetherimide.

The first electrode 500 is disposed on the substrate 400.

In an embodiment, the material of the first electrode 500 includes one or more of indium tin oxide, indium zinc oxide, zinc aluminum oxide, and indium gallium zinc oxide. In this embodiment, the first electrode 500 is an anode, and the material of the anode is ito.

The hole injection layer 100 is disposed on the first electrode 500. The material of the hole injection layer 100 is poly (3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT: PSS).

In one embodiment, the thickness W of the hole injection layer 100 is 10 nm-150 nm. Specifically, the thickness W of the hole injection layer 100 may be 10 nm, 20 nm, 40 nm, 60 nm, 80 nm, 100 nm, 140 nm, 150 nm, or the like.

In the present application, the thickness W of the hole injection layer 100 is set between 10 nm and 150 nm, so as to ensure the injection efficiency of the hole injection layer 100, enable the light emitting device 10 to display normally, and avoid the display performance of the light emitting device 10 from being affected.

The protective layer 290 includes a first protective portion 291. The first protection portion 291 is provided on the hole injection layer 100. The hole transport layer 200 is disposed on the first protective portion 291. The material of the first protection portion 291 includes P-type black phosphorus.

The P-type black phosphorus is low-dimensional black phosphorus, namely a single-layer or multi-layer two-dimensional nanosheet or a zero-dimensional quantum dot.

In one embodiment, the thickness of the first protection portion 291 is 20 nm to 100 nm. Specifically, the thickness of the first protective portion 291 may be 20 nm, 30 nm, 50 nm, 80 nm, 90 nm, 100 nm, or the like. In the present embodiment, the thickness of the first protection portion 291 is 30 nm.

In an embodiment, the material of the first protection portion 291 further includes an additional material. The additional material coats the outer surface of the P-type black phosphorus to form a nucleation shell material. The additional material is selected from one or more of dodecyl benzene sulfonate, polyvinylpyrrolidone, oleylamine, oleic acid, trioctylphosphine oxide, octadecyl phosphonic acid, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,4-benzenedithiol, 1,2-hexadecanediol, 1,7-diaminopentane, 1,4-diaminobenzene and tetradecylphosphonic acid.

In the present application, the first protection portion 291 is formed of a core-shell material in which P-type black phosphorus is coated with an additional material, and the additional material has lipophilicity, so that PEDOT: in the PSS, the PSS unit is prone to absorb water, which results in degradation of the subsequent hole transport layer 200 and influence on other film layers, thereby improving the light emitting efficiency, uniformity, stability and service life of the light emitting device 10.

The material of the protective layer contains only P-type black phosphorus or contains P-type black phosphorus and an additional material, and may not contain other materials.

It should be noted that the black phosphorus in this application can only be P-type black phosphorus. The other types of black phosphorus are used for preparing the protective layer, and only play opposite roles.

In one embodiment, the number of the P-type black phosphorus layers is 1-20. The transverse dimension of the P-type black phosphorus is 1 nanometer to 100 micrometers.

In one embodiment, the number of the P-type black phosphorus layers is 1-10. Specifically, the number of layers of the P-type black phosphorus may be 1,2, 5, 8, 10, or the like. The transverse dimension of the P-type black phosphorus is 1 nanometer to 10 micrometers. Specifically, the lateral dimension of the P-type black phosphorus may be 1 nm, 5 nm, 10 nm, 20 nm, 500 nm, 900 nm, 10 μm, or the like.

In one embodiment, the number of the P-type black phosphorus layers is 10-20. Specifically, the number of layers of the P-type black phosphorus may be 10, 12, 15, 18, 20, or the like. The lateral dimension of the P-type black phosphorus is 10-100 microns. Specifically, the lateral dimension of the P-type black phosphorus can be 10 microns, 20 microns, 35 microns, 50 microns, 75 microns, 95 microns, 100 microns, or the like.

In the present application, when the number of layers of the P-type black phosphorus is greater than 10, the band gap thereof is less than or equal to 0.3eV, and when the number of layers of the P-type black phosphorus is from 1 to 10, the band gap thereof is from 0.3eV to 2.5eV, i.e., the P-type black phosphorus can adjust the band gap thereof by adjusting the thickness. Therefore, the P-type black phosphorus is used to form the first protection portion 291, and the first protection portion 291 is disposed in the hole transport layer 200, that is, the first protection portion 291 is disposed between the hole injection layer 100 and the hole transport layer 200, so that a new energy level gradient is introduced between the hole injection layer 100 and the hole transport layer 200, and the adjustable band gap of the P-type black phosphorus is beneficial to the transport of holes, that is, the recombination of electrons and holes can be suppressed, and the barrier of the hole injection layer 100 and the hole transport layer 200 can be effectively reduced, thereby improving the light emitting efficiency of the light emitting device 10.

In this application, P type black phosphorus is low dimension P type black phosphorus, and low dimension P type black phosphorus has big specific surface area and flexibility, and low dimension P type black phosphorus is from cubic to the lamina, and its tension also can follow and change. Therefore, adjusting the thickness of the hole injection layer can adjust the stress between the hole transport layer 200 and the hole injection layer 100, thereby improving the contact performance between the hole transport layer 200 and the hole injection layer 100 and improving the connection between different film interfaces. The additional material with lipophilicity is arranged on the outer surface of the low-dimensional P-type black phosphorus, so that the additional material is combined with the material of the light-emitting layer 300, the deposition of the light-emitting layer 300 is facilitated, and the light-emitting uniformity of the light-emitting device 10 is improved.

In the present application, the P-type black phosphorus is a low-dimensional P-type black phosphorus, and the low-dimensional P-type black phosphorus has an adjustable band gap property, so that the low-dimensional P-type black phosphorus has good current saturation performance, high carrier mobility, and current modulation capability, and thus the light emitting device 10 can be effectively protected, and the light emitting device 10 is prevented from being inactivated, that is, the performance of the light emitting device 10 is improved.

In the present application, the first protection portion 291 is formed by using P-type black phosphorus, and the low-dimensional P-type black phosphorus can reduce the surface energy, thereby reducing the stress at the interface between the hole transport layer 200 and the hole injection layer 100, so as to improve the spreading degree of the film layer of the light emitting device 10 and improve the interface contact between the hole transport layer 200 and the hole injection layer 100.

In one embodiment, the material of the hole transport layer 200 includes Poly (9,9-dioctylfluorene-CO-N- (4-butylphenyl) diphenylamine) (TFB), polyvinylcarbazole (PVK), poly (N, N 'bis (4-butylphenyl) -N, N' -bis (phenyl) benzidine) (Poly-TPD), poly (9,9-dioctylfluorene-CO-bis-N,N-phenyl-1,4-Phenylenediamine) (PFB), 4,4',4 "-tris (carbazol-9-yl) triphenylamine (TCTA), 4,4' -bis (9-Carbazol) Biphenyl (CBP), N '-diphenyl-N, N' -bis (3-methylphenyl) -1,1 '-biphenyl-4,4' -diamine (TPD), N '-diphenyl-N, N' - (1-naphthyl) -1,1 '-biphenyl-4,4' -diamine (NPB), doped graphene, undoped graphene and C ₆₀ One or a combination of several of them.

In one embodiment, the thickness H of the hole transport layer 200 is 10 nm-150 nm. Specifically, the thickness H of the hole transport layer 200 may be 10 nm, 20 nm, 40 nm, 60 nm, 80 nm, 100 nm, 140 nm, 150 nm, or the like.

In the present application, the thickness H of the hole transport layer 200 is set between 10 nm and 150 nm, so as to ensure the transport efficiency of the hole transport layer 200, enable the light emitting device 10 to display normally, and avoid the display performance of the light emitting device 10 from being affected.

The light emitting layer 300 is disposed on the hole transport layer 200. The material of the light emitting layer 300 is selected from group ii-iv semiconductor nanocrystals, group iii-v semiconductor nanocrystals, group ii-v semiconductor nanocrystals, group iii-vi semiconductor nanocrystals, and group iv-vi semiconductor nanocrystals.

In an embodiment, the light emitting device 10 further comprises an electron transport layer 600. The electron transport layer 600 is disposed on the light emitting layer 300.

In one embodiment, the material of the electron transport layer 600 includes ZnO, tiO ₂ 、Alq ₃ SnO, zrO, alZnO, znSnO, 2,9-dimethyl-4,7-biphenyl-1, 10-phenanthroline (BCP), 3- (biphenyl-4-yl) -5- (4-tert-butylphenyl) -4-phenyl-4H-1,2,4-Triazole (TAZ), 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 1,3,5-tris (1-phenyl-1H-benzimidazol-2-yl) benzene (TPBI), 4,7-diphenyl-1, 10-phenanthroline (Bphen), and CsCO ₃ One or a combination of several of them.

In one embodiment, the thickness h of the electron transport layer 600 is 10 nm to 100 nm. Specifically, the thickness h of the electron transport layer 600 may be 10 nm, 24 nm, 44 nm, 58 nm, 80 nm, 90 nm, 94 nm, 100 nm, or the like.

In the present application, the thickness h of the electron transport layer 600 is set to 10 nm to 100 nm, so as to ensure the electron transport performance of the electron transport layer 600, and further ensure the normal display of the light emitting device 10.

In an embodiment, the light emitting device 10 further includes a second electrode 700. The second electrode 700 is disposed on the electron transport layer 600.

In one embodiment, the material of the second electrode 700 includes one or more of magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, cesium, barium, lithium fluoride, lithium dioxide, barium fluoride, and 8-hydroxyquinoline-lithium. In this embodiment, the second electrode 700 is a cathode made of silver.

In one embodiment, the second electrode 700 may be one or more layers.

Referring to fig. 2, fig. 2 is a schematic view of a second structure of a light emitting device according to an embodiment of the present disclosure. It should be noted that the second structure is different from the first structure in that:

the protective layer 290 includes a second protective portion 292. The first protective portion is not provided between the hole injection layer 100 and the hole transport layer 200. The hole transport layer 200 is disposed on the hole injection layer 100, and the second protection portion 292 is disposed on the hole transport layer 200. The material of the second protection portion 292 is the same as that of the first protection portion. That is, the material of the second protection portion 292 also includes P-type black phosphorus.

In one embodiment, the material of the second guard portion 292 further includes additional material. The additional material coats the P-type black phosphorus to form the core-shell material. The additional material is selected from one or more of dodecyl benzene sulfonate, polyvinylpyrrolidone, oleylamine, oleic acid, trioctylphosphine oxide, octadecyl phosphonic acid, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,4-benzenedithiol, 1,2-hexadecanediol, 1,7-diaminopentane, 1,4-diaminobenzene and tetradecylphosphonic acid.

In an embodiment, the second protection portion 292 is formed by coating P-type black phosphorus with an additional material to form a core-shell material, and the additional material has lipophilicity, so that PEDOT: in the PSS, the PSS unit easily absorbs water, which results in degradation of the light emitting layer 300 and influence on other film layers, thereby improving the light emitting efficiency, uniformity, stability and lifetime of the light emitting device 10. The second protection portion 292 is disposed between the hole transport layer 200 and the light emitting layer 300, so that a new energy level gradient is introduced between the hole transport layer 200 and the light emitting layer 300, and thus the barrier between the light emitting layer 300 and the hole transport layer 200 can be effectively reduced, thereby improving the light emitting efficiency of the light emitting device 10.

In this embodiment, the P-type black phosphorus is a low-dimensional P-type black phosphorus, which has a large specific surface area and flexibility, and the tension of the low-dimensional P-type black phosphorus changes from a block to a thin layer. Therefore, the stress between the hole transport layer 200 and the light emitting layer 300 can be adjusted by adjusting the thickness of the hole transport layer, so that the contact performance between the hole transport layer 200 and the light emitting layer 300 is improved, and the connection between different film interfaces can be improved. Meanwhile, the lipophilic additional material is arranged on the surface of the low-dimensional P-type black phosphorus, so that the combination of the lipophilic additional material and the material of the light-emitting layer is facilitated, the deposition of the light-emitting layer 300 is further facilitated, and the light-emitting uniformity of the light-emitting device 10 is improved.

In this embodiment, the second protection portion 292 is formed by using P-type black phosphorus, and the low-dimensional P-type black phosphorus can reduce the surface energy, thereby reducing the stress at the interface between the hole transport layer 200 and the light emitting layer 300, so as to improve the spreading degree of the device film and improve the interface contact between the light emitting layer 300 and the hole transport layer 200.

Referring to fig. 3, fig. 3 is a schematic view illustrating a third structure of a light emitting device according to an embodiment of the present disclosure. It should be noted that the third structure is different from the first structure in that:

the protective layer 290 includes a first protective portion 291 and a second protective portion 292. The first protective portion 291, the hole transport layer 200, and the second protective portion 292 are stacked in this order on the hole injection layer 100. The material of the first protective portion 291 and the material of the second protective portion 292 each include P-type black phosphorus.

In one embodiment, the number of layers and the lateral size of the P-type black phosphorus of the second protection portion 292 may be the same as those of the first protection portion 291.

In one embodiment, the number of layers and the lateral dimension of the P-type black phosphorus of the second protection portion 292 may be different from those of the first protection portion 291.

In one embodiment, the material of the first protection portion 291 and the material of the second protection portion 292 each further include additional material. The additional material coats the P-type black phosphorus to form the core-shell material. The additional material is selected from one or more of dodecyl benzene sulfonate, polyvinylpyrrolidone, oleylamine, oleic acid, trioctylphosphine oxide, octadecyl phosphonic acid, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,4-benzenedithiol, 1,2-hexadecanediol, 1,7-diaminopentane, 1,4-diaminobenzene and tetradecylphosphonic acid.

In an embodiment, the additional material of the second protection portion 292 may be the same as the additional material of the first protection portion 291.

In an embodiment, the additional material of the second protection portion 292 may be different from the additional material of the first protection portion 291.

In this embodiment, the first protection portion 291 and the second protection portion 292 are formed by coating P-type black phosphorus with an additional material to form a core-shell material, and the additional material has lipophilicity, so that PEDOT: in the PSS, the degradation of the hole transport layer 200 and the light emitting layer 300 and the influence on other film layers are caused because the PSS unit easily absorbs water, thereby improving the light emitting efficiency, uniformity, stability and lifetime of the light emitting device 10. When the number of the P-type black phosphorus layers is more than 10, the band gap is less than or equal to 0.3eV, and when the number of the P-type black phosphorus layers is between 1 and 10, the band gap is between 0.3eV and 2.5eV, namely the material of the P-type black phosphorus can adjust the band gap by adjusting the thickness. The first protection portion 291 and the second protection portion 292 are formed by using P-type black phosphorus, the first protection portion 291 is disposed between the hole injection layer 100 and the hole transport layer 200, and the second protection portion 292 is disposed between the hole transport layer 200 and the light emitting layer 300, so that a new energy level gradient is introduced between the hole injection layer 100 and the hole transport layer 200 and between the hole transport layer 200 and the light emitting layer 300, and further potential barriers between the light emitting layer 300 and the hole transport layer 200 and between the hole injection layer 100 and the hole transport layer 200 can be effectively reduced, and the light emitting efficiency of the light emitting device 10 is improved.

In this embodiment, the P-type black phosphorus is a low-dimensional P-type black phosphorus, which has a large specific surface area and flexibility, and the tension of the low-dimensional P-type black phosphorus changes from a block to a thin layer. Therefore, adjusting the thickness thereof can adjust the stress between the hole injection layer 100 and the hole transport layer 200 and between the hole transport layer 200 and the light emitting layer 300, thereby improving the contact performance between the hole injection layer 100 and the hole transport layer 200 and between the hole transport layer 200 and the light emitting layer 300, and improving the connection between different film interfaces. Meanwhile, the lipophilic additional material is arranged on the surface of the low-dimensional P-type black phosphorus, so that the additional material can be combined with the luminescent material, deposition of the luminescent layer 300 is facilitated, and the luminescent uniformity of the luminescent device 10 is improved.

In this embodiment, the first protection portion 291 and the second protection portion 292 are formed by using P-type black phosphorus, and the low-dimensional P-type black phosphorus can reduce the surface energy, thereby reducing the stress at the interface between the hole transport layer 200 and the light emitting layer 300, so as to improve the spreading degree of the device film and improve the interface contact between the light emitting layer 300 and the hole transport layer 200.

Referring to fig. 4, fig. 4 is a schematic view illustrating a fourth structure of a light emitting device according to an embodiment of the present disclosure. It should be noted that the fourth structure is different from the first structure in that: the light emitting device 10 is an inverted light emitting device, i.e., the first electrode 500 is a cathode and the second electrode 700 is an anode.

The present application provides a light emitting device 10, the protective layer 290 includes a first protective portion 291 and a second protective portion 292 by forming the protective layer 290 using P-type black phosphor. Since the P-type black phosphorus can adjust its band gap by adjusting its thickness, the first protection portion 291 is disposed between the hole injection layer 100 and the light emitting layer and/or the second protection portion 292 is disposed between the hole transport layer 200 and the light emitting layer 300, so that a new energy level gradient is introduced between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light emitting layer, and further, the barrier between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light emitting layer can be effectively reduced, thereby improving the light emitting efficiency of the light emitting device 10.

Further, by forming the protection layer 290 by using P-type black phosphorus, the band gap of the P-type black phosphorus can be adjusted by adjusting the thickness, the protection layer 290 includes a first protection portion 291 and a second protection portion 292, and the first protection portion 291 is disposed between the hole injection layer 100 and the hole transport layer 200 and/or the second protection portion 292 is disposed between the hole transport layer 200 and the light emitting layer 300, so that a new energy level gradient is introduced between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light emitting layer 300, and further, the barrier between the light emitting layer 300 and the hole transport layer 200 and/or between the hole injection layer 100 and the hole transport layer 200 can be effectively reduced, and the light emitting efficiency of the light emitting device 10 can be improved.

Further, the first protection portion 291 and the second protection portion 292 are formed by coating P-type black phosphorus with an additional material to form a core-shell material, and the additional material has lipophilicity, so that PEDOT: in the PSS, the PSS unit is prone to absorb water, so that the degradation of the hole transport layer 200 and/or the light emitting layer 300 and the influence on other film layers are caused, and the light emitting efficiency, uniformity, stability and service life of the light emitting device 10 are improved; the P-type black phosphorus is low-dimensional P-type black phosphorus, the low-dimensional P-type black phosphorus has large specific surface area and flexibility, the tension of the low-dimensional P-type black phosphorus is changed from a block to a thin layer, and therefore the thickness of the low-dimensional P-type black phosphorus can be adjusted to adjust the stress between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light emitting layer 300, further the contact performance between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light emitting layer 300 is improved, the connection between different film interfaces can be improved, meanwhile, the surface of the low-dimensional P-type black phosphorus is provided with a lipophilic additional material, the deposition of the quantum dot light emitting layer 300 with a ligand is facilitated, and the light emitting uniformity of the light emitting device 10 is improved.

Further, the first protection portion 291 and the second protection portion 292 are formed by using P-type black phosphorus, and the low-dimensional P-type black phosphorus can reduce surface energy, thereby reducing stress at an interface between the hole injection layer 100 and the hole transport layer 200 and/or an interface between the hole transport layer 200 and the light emitting layer 300, thereby increasing a spreading degree of a film layer of the light emitting device 10 and improving interface contact between the light emitting layer 300 and the hole transport layer 200.

Referring to fig. 1 and 5, fig. 5 is a flowchart of a method for manufacturing a light emitting device according to an embodiment of the present disclosure. The present application further provides a method for manufacturing the light emitting device 10, which is specifically described as follows:

example 1:

b11, providing a substrate.

In an embodiment, after step B11, the method further includes:

a first electrode 500 is disposed on the substrate 400. The first electrode 500 is an anode. The material of the first electrode 500 is indium tin oxide.

And B12, forming a hole injection layer on the substrate.

Specifically, poly (3,4-ethylenedioxythiophene) is spin coated, ink jet printed, or coated on the first electrode 500: polystyrene sulfonic acid (PEDOT: PSS) forms the hole injection layer 100. In this embodiment, spin coating is used as an example for explanation.

And B13, sequentially laminating a protective layer and a hole transport layer on the hole injection layer, wherein the material of the protective layer comprises P-type black phosphorus.

Specifically, a material solution of the protective layer 290 is spin-coated, ink-jet printed, or coated on the hole injection layer 100 to form the first protective portion 291 of the protective layer 290. The thickness of the first protection portion 291 is 30 nm. In this embodiment, spin coating is used as an example for explanation.

Then, the hole transport layer 200 having a thickness of 30 nm was formed on the first protective portion 291 by spin coating, inkjet printing, or coating PVK. In this embodiment, spin coating is used as an example for explanation.

In one embodiment, the spin speed is 5000 rpm to 6200 rpm. Specifically, the spin coating speed may be 5000 rpm, 5200 rpm, 5600 rpm, 6000 rpm, 6200 rpm, or the like. In the present example, the spin speed was 6000 rpm.

In one embodiment, the spin coating time is 15 seconds to 25 seconds. Specifically, the spin coating time may be 15 seconds, 18 seconds, 20 seconds, 23 seconds, 25 seconds, or the like. In this example, the spin coating time was 20 seconds.

In one embodiment, the concentration of the material solution of the protective layer 290 is between 8 milligrams per liter and 12 milligrams per liter. Specifically, the concentration of the material solution of the protective layer 290 is 8 mg per liter, 9 mg per liter, 10 mg per liter, or 12 mg per liter, etc. In this embodiment, the concentration of the material solution of the protective layer 290 is 8 mg per liter.

In the application, the spin-coating rotation speed is set to 5000 rpm to 6200 rpm, the spin-coating time is set to 15 seconds to 25 seconds, the concentration of the material solution of the protective layer 290 is set to 8 milligrams per liter to 12 milligrams per liter, the film-forming quality of the protective layer 290 can be controlled, and the performance of the light-emitting device 10 is further ensured.

In an embodiment, the material of the first protection portion 291 further includes an additional material. The additional material coats the outer surface of the P-type black phosphorus to form the nuclear shell material through Van der Waals force, electrostatic interaction or coordination. The additional material is selected from one or more of dodecyl benzene sulfonate, polyvinylpyrrolidone, oleylamine, oleic acid, trioctylphosphine oxide, octadecyl phosphonic acid, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,4-benzenedithiol, 1,2-hexadecanediol, 1,7-diaminopentane, 1,4-diaminobenzene and tetradecylphosphonic acid. In this embodiment, a core-shell material is described as an example of the material of the first protective portion 291.

Preparation of the core-shell material:

grinding the blocky P-type black phosphorus crystal into powder, adding N-methyl pyrrolidone (NMP) and NaOH, violently stirring for 2-8 hours at the temperature of 15-60 ℃, centrifuging for 10-20 minutes at the rotating speed of 3000-8000 rpm, and taking supernatant to obtain a solution containing P-type black phosphorus; wherein, the number of the P-type black phosphorus layers is 10-20, and the transverse dimension of the P-type black phosphorus is 10-100 microns. In this example, the stirring temperature is 40 degrees centigrade, the stirring time is 7 hours, the centrifugal rotation speed is 5000 rpm, the centrifugal time is 19 minutes, the number of layers of the P-type black phosphorus is 11, and the transverse dimension of the P-type black phosphorus is 10 micrometers.

Specifically, grinding the blocky P-type black phosphorus crystal into powder, adding N-methyl pyrrolidone (NMP) and NaOH, violently stirring for 7 hours at the temperature of 40 ℃, centrifuging for 19 minutes per minute at the rotating speed of 5000 rpm, and taking supernatant to obtain a solution containing 11 layers of P-type black phosphorus and 10 micrometers of transverse dimension.

Then, 10 mg of P-type black phosphorus having 11 layers and a lateral size of 10 μm was redispersed in NMP solvent; then, 1 mg to 10 mg of oleylamine/trioctylphosphine/polyvinylpyrrolidone is added; performing ultrasonic treatment for 1 hour, and stirring for 5 hours; then, the core-shell material was centrifuged and redispersed in a chloroform solvent to obtain a core-shell material.

In one embodiment, the stirring temperature is 15-60 degrees Celsius. Specifically, the stirring temperature may be 15 degrees celsius, 20 degrees celsius, 30 degrees celsius, 40 degrees celsius, 50 degrees celsius, 60 degrees celsius, or the like.

In one embodiment, the stirring time is from 2 hours to 8 hours. Specifically, the stirring time may be 2 hours, 2.6 hours, 3 hours, 5 hours, 7 hours, 8 hours, or the like.

In one embodiment, the centrifugal speed is 3000 rpm to 8000 rpm. Specifically, the centrifugal rotation speed may be 3000 rpm, 5500 rpm, 7000 rpm, 8000 rpm, or the like. In one embodiment, the centrifugation time is 10 minutes to 20 minutes. Specifically, the centrifugation time may be 10 minutes, 12 minutes, 15 minutes, 17 minutes, 20 minutes, or the like.

In the application, the stirring temperature is set to be 15-60 ℃, the stirring time is set to be 2-8 hours, the centrifugal rotating speed is set to be 3000-8000 rpm, and the centrifugal time is set to be 10-20 minutes, so that the number of the obtained P-type black phosphorus layers is 10-20, and the transverse size of the P-type black phosphorus is 10-100 micrometers.

And B14, forming a light-emitting layer on the hole transport layer.

The group ii-v semiconductor nanocrystal form light emitting layer 300 is spin coated, ink jet printed, or coated on the hole transport layer 200. In this embodiment, spin coating is used as an example for description.

In an embodiment, after step B14, the method further includes:

the electron transport layer 600 is formed on the light emitting layer 300 by spin coating, ink jet printing, or coating ZnO. In this embodiment, spin coating is used as an example for explanation.

After the step of disposing the electron transport layer 600 on the light emitting layer 300, further comprising:

magnesium is disposed on the electron transport layer 600 to form the second electrode 700.

Example 2:

please continue to refer to fig. 1. The P-type black phosphorus with 11 layers and a lateral size of 10 micrometers in example 1 was changed to P-type black phosphorus with 10 layers and a lateral size of 500 nm to 10 micrometers. The stirring temperature of 40 ℃, the stirring time of 7 hours, the centrifugal speed of 5000 rpm and the centrifugal time of 19 minutes were changed to 60 ℃, the stirring time of 8 hours, the centrifugal speed of 8000 rpm and the centrifugal time of 20 minutes.

In this application, set up stirring temperature to 60 degrees centigrade, the churning time sets up to 8 hours, and the centrifugation rotational speed sets up to 8000 revolutions per minute, and the centrifugation time sets up to 20 minutes for the number of layers of the black phosphorus of P type that obtains is 10 layers, and the to size of the black phosphorus of P type is 500 nanometers-10 microns.

Example 3:

please continue to refer to fig. 1. The P-type black phosphorus with 10-20 layers and the transverse dimension of 10-100 microns in the example 1 is changed into the P-type black phosphorus with 1-10 layers and the transverse dimension of 1 nanometer-10 microns. The stirring temperature is 15-60 ℃, the stirring time is 2-8 hours, the centrifugal speed is 3000-8000 rpm, and the centrifugal time is 10-20 minutes, the stirring temperature is 60-200 ℃, the stirring time is 8-1000 hours, the centrifugal speed is 8000-15000 rpm, and the centrifugal time is 20-100 minutes. In this example, the stirring temperature is 200 degrees centigrade, the stirring time is 1000 hours, the centrifugal rotation speed is 15000 rpm, the centrifugal time is 100 minutes, the number of layers of the P-type black phosphorus is 1-2, and the transverse dimension of the P-type black phosphorus is 1 nm.

In one embodiment, the stirring temperature is 60-200 degrees Celsius. Specifically, the stirring temperature may be 60 degrees celsius, 90 degrees celsius, 110 degrees celsius, 150 degrees celsius, 190 degrees celsius, or 200 degrees celsius, or the like.

In one embodiment, the stirring time is from 8 hours to 1000 hours. Specifically, the stirring time may be 8 hours, 50 hours, 250 hours, 750 hours, 900 hours, 1000 hours, or the like.

In one embodiment, the centrifuge speed is 8000 rpm to 15000 rpm. Specifically, the centrifugal rotation speed may be 8000 rpm, 9000 rpm, 12000 rpm, 15000 rpm, or the like.

In one embodiment, the centrifugation time is 20 minutes to 100 minutes. Specifically, the centrifugation time may be 20 minutes, 50 minutes, 60 minutes, 80 minutes, 100 minutes, or the like. In this example, the centrifugation time was 20 minutes.

In the application, the stirring temperature is set to be 60-200 ℃, the stirring time is set to be 8-1000 hours, the centrifugal rotating speed is set to be 8000-15000 rpm, and the centrifugal time is set to be 20-100 minutes, so that the number of layers of the obtained P-type black phosphorus is 1-10 layers, and the transverse size of the P-type black phosphorus is 1 nanometer-10 micrometers.

Example 4:

please continue to refer to fig. 2. The difference from example 1 is that: instead of providing the first protective portion between the hole injection layer 100 and the hole transport layer 200, a second protective portion 292 is provided on the hole transport layer 200 after the step of providing the hole transport layer 200 in embodiment 1.

Example 5:

please continue with fig. 2. The difference from example 2 is that: instead of providing the first protective portion between the hole injection layer 100 and the hole transport layer 200, a second protective portion 292 is provided on the hole transport layer 200 after the step of providing the hole transport layer 200 in embodiment 2.

Example 6:

please continue with fig. 2. The difference from example 3 is that: instead of providing the first protective portion between the hole injection layer 100 and the hole transport layer 200, the step of providing the hole transport layer 200 in embodiment 3 is followed by providing the second protective portion 292 on the hole transport layer 200.

Example 7:

please continue to refer to fig. 3. After the step of sequentially stacking and disposing the first protective portion 291 and the hole transport layer 200 on the hole injection layer 100 in embodiment 1, the second protective portion 292 is further disposed on the hole transport layer 200. A core-shell material containing P-type black phosphorus having 15 layers and a lateral size of 10 to 100 micrometers is used as the material of the first protective portion 291. The core-shell material containing 5 layers of P-type black phosphorus with a transverse dimension of 5 nm to 20 nm is used as the material of the second protection portion 292.

The core-shell material containing the P-type black phosphorus with 15 layers and the transverse size of 10-100 micrometers is prepared by the following steps:

grinding the blocky P-type black phosphorus crystal into powder; then, adding N-methyl pyrrolidone (NMP) and NaOH; then, vigorously stirring for 2.5 hours at the temperature of 17 ℃, centrifuging for 11 minutes at the rotating speed of 4500 rpm, and taking supernatant to obtain a solution containing P-type black phosphorus; namely, the number of the P-type black phosphorus layers is 15, and the transverse dimension of the P-type black phosphorus is 10-100 microns. Then, 10 mg of P-type black phosphorus having 15 layers and a lateral size of 10 to 100 μm was re-dispersed in the NMP solvent; then, 3 mg of polyvinylpyrrolidone was added thereto; then, carrying out ultrasonic treatment for 1 hour, and stirring for 5 hours; then, centrifuged and redispersed in chloroform solvent.

The core-shell material containing the P-type black phosphorus with 5 layers and the transverse dimension of 5-20 nanometers is prepared as follows:

grinding the blocky P-type black phosphorus crystal into powder; then, adding N-methyl pyrrolidone (NMP) and NaOH; then, vigorously stirring for 500 hours at the temperature of 150 ℃, centrifuging for 60 minutes at the rotating speed of 10000 rpm, and taking supernatant to obtain a solution containing P-type black phosphorus; namely, the number of the P-type black phosphorus layers is 5, and the transverse dimension of the P-type black phosphorus is 5-20 nanometers. Then, 10 mg of P-type black phosphorus with 5 layers and a transverse dimension of 5-20 nm is re-dispersed into the NMP solvent; then, 3 mg of polyvinylpyrrolidone was added thereto; then, carrying out ultrasonic treatment for 1 hour, and stirring for 5 hours; then, it was centrifuged and redispersed in a chloroform solvent.

Other steps are as described in embodiment 1, and are not described herein again.

In this application, the stirring temperature is set to 17 degrees celsius, the stirring time is set to 2.5 hours, the centrifugal rotation speed is set to 45 revolutions per minute, and the centrifugal time is set to 11 minutes, so that the number of layers of the obtained P-type black phosphorus is 15, and the transverse dimension of the P-type black phosphorus is 10-100 micrometers. The stirring temperature is set to 150 ℃, the stirring time is set to 500 hours, the centrifugal rotating speed is set to 10000 rpm, and the centrifugal time is set to 50 minutes, so that the number of layers of the obtained P-type black phosphorus is 5, and the transverse dimension of the P-type black phosphorus is 5-20 nanometers.

Example 8:

please continue to refer to fig. 1. Example 8 differs from example 1 in that: after the step of forming the hole injection layer 100, the substrate 400, the first electrode 500, and the hole injection layer 100 are ultrasonically cleaned with acetone, deionized water, and isopropyl alcohol, and then dried for later use.

Then, grinding the blocky P-type black phosphorus into powder, adding NMP and NaOH, violently stirring for 500 hours at 40 ℃, centrifuging for 50 minutes at 10000 rpm, and taking supernatant fluid to obtain solution containing 5 layers of P-type black phosphorus with the transverse dimension of 20 nanometers.

Then, mixing the obtained P-type black phosphorus solution with oleylamine/trioctylphosphine/polyvinylpyrrolidone, and then carrying out ultrasonic treatment for 1 hour and stirring for 5 hours; then, it was centrifuged and redispersed in a chloroform solvent. And spin-coated on the hole injection layer 100 at a spin-coating speed of 2000 rpm, and then placed in a nitrogen glove box to be dried to obtain a protective layer. The rest is as described in embodiment 1, and is not described herein again.

Comparative example 1:

the protective layer 290 is not provided in the light-emitting device 10 of embodiment 1. Other steps are as described in embodiment 1, and are not described herein again.

Comparative example 2:

comparative example 2 differs from example 8 in that: the first protective portion 291 is not formed using P-type black phosphorus, but P-type black phosphorus is doped in the hole transport layer 200.

Specifically, in the formation of hole injectionAfter the step of forming the layer 100, the substrate 400, the first electrode 500, and the hole injection layer 100 are ultrasonically cleaned with acetone, deionized water, and isopropyl alcohol, and then dried for use. Then, grinding the blocky P-type black phosphorus into powder, adding NMP and NaOH, violently stirring for 500 hours at 40 ℃, centrifuging for 50 minutes at 10000 rpm, and taking supernatant to obtain a solution containing 5 layers of P-type black phosphorus with the transverse dimension of 20 nanometers. Then, WO of nanometer order is added ₃ Placing in isopropanol, centrifuging at 1000 rpm for 40 min, removing large particles, and removing supernatant to obtain nanometer WO ₃ And (3) solution. Then, the obtained solution of the P-type black phosphorus is mixed with the nano-scale WO ₃ Mixing the solutions, reacting at 70 deg.C for 30 min to obtain mixed solution, adding WO ₃ The mass ratio of the P-type black phosphorus to the P-type black phosphorus is 10; then, the obtained mixed solution was spin-coated on the hole injection layer 100 at a spin speed of 2000 rpm, and then placed in a nitrogen glove box to be dried to obtain a hole transport layer. Other steps are as described in embodiment 8, and are not described herein again.

Referring to fig. 6, fig. 6 is a current density-voltage curve of the light emitting device 10 according to the embodiment of the present disclosure. It can be seen that the light-emitting device 10 using the additional material to cover the outer surface of the P-type black phosphorus to form the protection layer 290 has the current density of 80mA/cm at the maximum in the light-emitting device 10 of example 1 when a voltage of 6 v is input ² The current density of the light-emitting device 10 of embodiment 2 can reach up to 70mA/cm ² The current density of the light-emitting device 10 of example 3 can reach 73mA/cm at the maximum ² The current density of the light-emitting device 10 of example 4 can reach 50mA/cm at the maximum ² The light-emitting device 10 of example 5 can have a current density of up to 27mA/cm ² The current density of the light-emitting device 10 of example 1 can be up to 104mA/cm ² The current density of the light-emitting device 10 of example 7 can reach 175mA/cm at the maximum ² The current density of the light-emitting device 10 of example 8 can reach up to 67mA/cm ² B, carrying out the following steps of; in the prior art, the P-type black phosphorus is not used in the light-emitting device to form the protective layer, and when the light-emitting device inputs 6 volts, the current density can only reach 23 mA-cm ² . Or, the P-type black phosphorus is doped in the hole transport layer, and the current density of the light-emitting device can only reach 60mA/cm at the maximum when the light-emitting device inputs 6 volts ² . Therefore, in the light emitting device 10 of the present application, the protective layer 290 is formed by coating the outer surface of the P-type black phosphorus with the additional material, so that the mobility of carriers is improved, and the performance of the light emitting device 10 is improved.

Referring to fig. 7-9, fig. 7 is a bar graph illustrating external quantum efficiency of a light emitting device according to an embodiment of the present disclosure over time. Fig. 8 is a bar graph of external quantum efficiency over time for a first prior art light emitting device. Fig. 9 is a bar graph of external quantum efficiency over time for a second prior art light emitting device. From this, it is understood that the light emitting device 10 in which the additional material is coated on the outer surface of the P-type black phosphorus to form the protective layer 290 has a small change in external quantum efficiency with time, that is, the light emitting device 10 in which the core-shell material is applied can improve the stability of the light emitting device 10. In the light emitting device without the protective layer in the prior art, the external quantum efficiency gradually decreases with time, that is, the light emitting device in the prior art is unstable. Therefore, in the present application, applying the core-shell material to the light emitting device 10 may improve the stability of the light emitting device 10.

It should be noted that "T" in the drawings indicates one day. For example, "T1" is 1 day, and "T20" is 20 days.

The application also provides a display panel, which comprises the light-emitting device provided by the application. The performance of the display panel is improved.

The embodiment of the application discloses a light-emitting device, a preparation method thereof and a display panel, wherein a protective layer 290 is formed by adopting P-type black phosphorus, and because the P-type black phosphorus can adjust the material of the band gap thereof by adjusting the thickness, when the protective layer 290 is arranged between a hole injection layer 100 and a hole transport layer 200 and/or between the hole transport layer 200 and a light-emitting layer 300, a new energy level gradient can be introduced between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light-emitting layer 300, so that the potential barrier between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light-emitting layer 300 can be effectively reduced, and the light-emitting efficiency of the light-emitting device 10 is further improved.

Furthermore, the protective layer 290 is formed by using P-type black phosphorus, which is low-dimensional P-type black phosphorus, the low-dimensional P-type black phosphorus has large specific surface area and flexibility, and the tension of the low-dimensional P-type black phosphorus changes from a block to a thin layer, so that the stress between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light-emitting layer 300 can be adjusted by adjusting the thickness of the low-dimensional P-type black phosphorus, thereby improving the contact performance inside the hole transport layer 200 and between the hole injection layer 100 and the hole transport layer 200 and/or between the hole transport layer 200 and the light-emitting layer 300, and improving the connection among different film interfaces. The protective layer 290 is formed by using P-type black phosphorus, which is low-dimensional P-type black phosphorus, and the low-dimensional P-type black phosphorus has a unique band gap property, so that the low-dimensional P-type black phosphorus has good current saturation performance, high carrier mobility and current modulation capability, and has a very high circuit leakage current modulation rate, thereby effectively protecting the light emitting device 10, avoiding the light emitting device 10 from being inactivated, i.e., improving the performance of the light emitting device 10. The protective layer 290 is formed by adopting P-type black phosphorus, the P-type black phosphorus is low-dimensional P-type black phosphorus, and the low-dimensional P-type black phosphorus can reduce the surface energy, so that the stress of the interface of the hole injection layer 100 and the hole transport layer 200 and/or the interface of the hole transport layer 200 and the light-emitting layer 300 is reduced, the spreading degree of a device film layer is improved, and the interface contact between the light-emitting layer 300 and the hole transport layer 200 is improved.

Further, a core-shell material formed by arranging an additional material on the outer surface of the low-dimensional P-type black phosphorus is used as the material of the protection layer 290, the additional material is lipophilic, and the additional material is combined with the material of the light-emitting layer 300, so that the deposition of the light-emitting layer 300 is facilitated, and the light-emitting uniformity of the light-emitting device 10 is improved. The core-shell material formed by arranging the additional material on the outer surface of the low-dimensional P-type black phosphorus is used as the material of the protective layer 290, the additional material is lipophilic, and the situation that the hole injection layer 100 adopts PEDOT: when the PSS is formed, the PSS unit easily absorbs water, which causes degradation of the hole transport layer 200 and influence on other film layers, thereby improving the light emitting efficiency, uniformity, stability, and lifespan of the light emitting device 10.

The light emitting device, the manufacturing method thereof, and the display panel provided in the embodiments of the present application are described in detail above, and the principles and embodiments of the present application are explained in the present application by applying specific examples, and the description of the above embodiments is only used to help understanding the method and the core concept of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and the application scope may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A light-emitting device is characterized by comprising a protective layer, a hole injection layer and a hole transport layer, wherein the protective layer and the hole transport layer are arranged on the hole injection layer, and the material of the protective layer comprises P-type black phosphorus.

2. The light-emitting device according to claim 1, wherein the material of the protective layer further comprises an additional material, the additional material coats the P-type black phosphorus to form a core-shell material, and the additional material is selected from one or more of dodecylbenzene sulfonate, polyvinylpyrrolidone, oleylamine, oleic acid, trioctylphosphine oxide, octadecylphosphonic acid, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,4-benzenedithiol, 1,2-hexadecanediol, 1,7-diaminopentane, 1,4-diaminobenzene, and tetradecylphosphonic acid.

3. The light-emitting device according to claim 1, wherein the protective layer comprises a first protective portion, and wherein the first protective portion and the hole-transporting layer are sequentially stacked and disposed on the hole-injecting layer.

4. The light-emitting device according to claim 1, wherein the protective layer comprises a second protective portion, and wherein the hole-transporting layer and the second protective portion are sequentially stacked over the hole-injecting layer.

5. The light-emitting device according to claim 1, wherein the protective layer comprises a first protective portion and a second protective portion, and wherein the first protective portion, the hole-transport layer, and the second protective portion are stacked in this order on the hole-injection layer.

6. The light-emitting device according to claim 1, wherein the number of the layers of the P-type black phosphorus is 1 to 10, and the lateral dimension of the P-type black phosphorus is 1 nm to 10 μm.

7. The light-emitting device according to claim 1, wherein the number of layers of the P-type black phosphorus is 10-20, and the lateral dimension of the P-type black phosphorus is 10-100 μm.

8. The light-emitting device according to claim 1, further comprising a light-emitting layer, a first electrode, and a second electrode, wherein the hole injection layer is provided on the first electrode, the protective layer and the hole transport layer are both provided between the light-emitting layer and the hole injection layer, and the second electrode is provided on the light-emitting layer.

9. A preparation method of a light-emitting device is characterized by comprising a step of forming a protective layer, a step of forming a hole injection layer and a step of forming a hole transport layer, wherein the protective layer is made of P-type black phosphorus.

10. A display panel comprising the light-emitting device according to any one of claims 1 to 8 or the light-emitting device manufactured by the manufacturing method according to claim 9.