Light emitting device and method of fabricating the same

Abstract

The application relates to a light-emitting device and a manufacturing method thereof. The light-emitting device comprises an anode layer, a light-emitting layer and a cathode layer which are sequentially stacked. The light-emitting layer contains quantum dot light-emitting material, the electron transport layer contains electron transport material and a first additive, and the hole injection layer contains hole injection material and a second additive. The molecular structure of the first additive and the second additive is that the additive can reduce the LUMO energy level of the electron transport material, hinder the electron injection from the cathode layer to the electron transport layer, and establish an interface dipole at the interface between the electron transport layer and the light-emitting layer, so that the injection of the electron from the electron transport layer to the light-emitting layer is further hindered, thereby reducing the imbalance between the number of holes and electrons in the light-emitting layer and improving the device efficiency and stability. The additive can reduce the HOMO energy level of the hole injection material, promote the injection of the hole, thereby reducing the imbalance between the number of holes and electrons in the light-emitting layer and improving the device efficiency and stability.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic technology, and in particular to a light-emitting device and its fabrication method. Background Technology

[0002] Display technology has achieved several qualitative leaps, from early cathode ray tube (CRT) displays to liquid crystal displays (LCD) and plasma flat panel displays (PDP) in the 1980s, and now to mainstream organic light-emitting diode (OLED) and quantum dot light-emitting diode (QLED) displays.

[0003] OLED devices have become the mainstream technology in the display field due to their advantages such as self-emission, simple structure, thinness, fast response, wide viewing angle, low power consumption, and flexible display. QLED devices, with their advantages of saturated emitted light color, tunable wavelength, and high luminous quantum yield, have become a strong competitor to OLED in recent years.

[0004] In traditional QLED devices, carrier functional layers such as a hole injection layer (HIL), a hole transport layer (HTL), and an electron transport layer (ETL) are typically placed on both sides of the quantum dot light-emitting layer to control the transport of holes and electrons. For example, the structure of a QLED device is: anode / hole injection layer / hole transport layer / quantum dot light-emitting layer / electron transport layer / cathode.

[0005] The electron transport layer of QLED devices typically uses inorganic nanoparticle oxides, such as ZnO, BaO, and TiO2, with a LUMO energy level generally around 4 eV, which is very close to the LUMO energy level of quantum dot luminescent materials. Therefore, the energy level barrier that electrons need to overcome to travel from the electron transport layer to the quantum dot luminescent layer is very small. However, the hole mobility in the hole transport layer is several orders of magnitude lower than that in the electron transport layer, leading to an imbalance in the number of holes and electrons transported to the quantum dot luminescent layer. This results in the quantum dot material becoming charged, causing Auger recombination and other non-radiative luminescence, thus reducing device efficiency and stability. Summary of the Invention

[0006] Therefore, it is necessary to provide a light-emitting device and its fabrication method to solve the problem of the imbalance between the number of holes and electrons transmitted to the quantum dot light-emitting layer.

[0007] One object of the present invention is to provide a light-emitting device, the solution of which is as follows:

[0008] A light-emitting device, characterized in that it comprises an anode layer, a light-emitting layer and a cathode layer stacked sequentially, wherein the light-emitting layer contains quantum dot light-emitting material;

[0009] The light-emitting device further includes an electron transport layer disposed between the light-emitting layer and the cathode layer, the electron transport layer containing an electron transport material and a first additive; and / or

[0010] The light-emitting device further includes a hole injection layer disposed between the light-emitting layer and the anode layer, the hole injection layer containing a hole injection material and a second additive;

[0011] The first additive and the second additive are each independently selected from at least one of the following compounds:

[0012]

[0013] R11 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C18 heteroaryl.

[0014] R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1 to C20 alkyl groups;

[0015] R21 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C20 alkyl;

[0016] R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1 to C20 alkyl groups;

[0017] The substituents are independently selected from one or more of the following: C1-C10 ester group, C1-C10 amide group, C1-C10 alkoxy group, C1-C10 alkylthio group, C1-C10 alkyl group, C6-C10 aryl group, carboxyl group, mercapto group, phosphono group, phosphonic acid group, amino group, nitro group, cyano group, halogen group, hydroxyl group, and vinyl group.

[0018] In one embodiment, R11 is selected from: substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C18 heteroaryl, preferably substituted or unsubstituted C6-C10 aryl, such as phenyl, naphthyl, 2-methylphenyl, 2-methylnaphthyl.

[0019] R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1 to C10 alkyl, preferably C1 to C10 alkyl, such as methyl, ethyl, n-propyl, isopropyl;

[0020] R21 is selected from: substituted or unsubstituted C6-C18 aryl groups, substituted or unsubstituted C1-C10 alkyl groups, preferably substituted or unsubstituted C6-C10 aryl groups, such as phenyl, naphthyl, 2-methylphenyl, 2-methylnaphthyl.

[0021] R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1 to C10 alkyl groups, preferably carboxyl.

[0022] In one embodiment, the first additive and the second additive are each independently selected from at least one of the following compounds:

[0023]

[0024]

[0025] In one embodiment, the electron transport material is selected from at least one of metal oxides or doped metal oxides, preferably, the metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2.

[0026] In one embodiment, the doped metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2, and the doping element is selected from at least one of Al, Mg and Li.

[0027] In one embodiment, the electron transport material has a mass fraction of 90-99% in the electron transport layer, and the first additive has a mass fraction of 1%-10% in the electron transport layer.

[0028] Preferably, the electron transport material has a mass fraction of 93%-97% in the electron transport layer, and the first additive has a mass fraction of 3%-7% in the electron transport layer.

[0029] In one embodiment, the material of the hole injection layer is selected from at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tin compounds, doped graphene, undoped graphene, and C60.

[0030] In one embodiment, the hole injection material has a mass fraction of 60%-99% in the hole injection layer, and the second additive has a mass fraction of 1%-40% in the hole injection layer;

[0031] Preferably, the mass fraction of the hole injection material in the hole injection layer is 65% to 90%, and the mass fraction of the second additive in the hole injection layer is 10% to 35%.

[0032] In one embodiment, the light-emitting device further includes a hole transport layer disposed between the hole injection layer and the light-emitting layer, wherein the material of the hole transport layer is selected from one or more of TPD, poly-TPD, PVK, CBP, NPB, TCTA, mCP, TAPC, and TFB.

[0033] In one embodiment, the quantum dot luminescent material is selected from at least one of single-structure quantum dots and core-shell structure quantum dots. The single-structure quantum dot material is selected from at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdSe ... The group IV-VI compound is selected from at least one of dZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and SnPbTe. At least one of SnPbSSe, SnPbSeTe, and SnPbSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, G At least one of aInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb, wherein the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot includes any one of the above-mentioned single-structure quantum dots, and the shell material of the core-shell quantum dot includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS, and the above-mentioned single-structure quantum dots.

[0034] One object of the present invention is to provide a method for manufacturing a light-emitting device, the solution of which is as follows:

[0035] A method for manufacturing a light-emitting device includes the following steps:

[0036] A method for manufacturing a light-emitting device includes the following steps:

[0037] A cathode layer is fabricated on the substrate;

[0038] An electron transport layer is fabricated on the cathode layer;

[0039] A light-emitting layer is fabricated on the electron transport layer;

[0040] A hole injection layer is fabricated on the light-emitting layer;

[0041] A light-emitting layer is prepared on the hole injection layer;

[0042] An anode layer is fabricated on the light-emitting layer to obtain the light-emitting device;

[0043] or,

[0044] An anode layer is fabricated on the substrate;

[0045] A hole injection layer is fabricated on the anode layer;

[0046] A light-emitting layer is fabricated on the hole injection layer;

[0047] An electron transport layer is fabricated on the light-emitting layer;

[0048] A cathode layer is fabricated on the electron transport layer to obtain the light-emitting device;

[0049] The light-emitting layer contains quantum dot light-emitting material;

[0050] Preferably, the electron transport layer contains an electron transport material and a first additive.

[0051] And / or, the hole injection layer contains a hole injection material and a second additive;

[0052] The first additive and the second additive are each independently selected from at least one of the following compounds:

[0053]

[0054] R11 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C18 heteroaryl.

[0055] R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1 to C20 alkyl groups;

[0056] R21 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C20 alkyl;

[0057] R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1 to C20 alkyl groups;

[0058] The substituents are independently selected from one or more of the following: C1-C10 ester group, C1-C10 amide group, C1-C10 alkoxy group, C1-C10 alkylthio group, C1-C10 alkyl group, C6-C10 aryl group, carboxyl group, mercapto group, phosphono group, phosphonic acid group, amino group, nitro group, cyano group, halogen group, hydroxyl group, and vinyl group.

[0059] In one embodiment, the electron transport material is selected from at least one of metal oxides or doped metal oxides, preferably, the metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2;

[0060] Preferably, the metal oxide in the doped metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2, and the doping element is selected from at least one of Al, Mg and Li.

[0061] Preferably, the electron transport material has a mass fraction of 90-99% in the electron transport layer, and the first additive has a mass fraction of 1%-10% in the electron transport layer;

[0062] More preferably, the electron transport material has a mass fraction of 93%-97% in the electron transport layer, and the first additive has a mass fraction of 3%-7% in the electron transport layer.

[0063] In one embodiment, the material of the hole injection layer is selected from at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tin compounds, doped graphene, undoped graphene, and C60.

[0064] Preferably, the mass fraction of the hole injection material in the hole injection layer is 60%-99%, and the mass fraction of the second additive in the hole injection layer is 1%-40%.

[0065] More preferably, the hole injection material has a mass fraction of 65% to 90% in the hole injection layer, and the second additive has a mass fraction of 10% to 35% in the hole injection layer.

[0066] In one embodiment, the light-emitting device further includes a hole transport layer disposed between the hole injection layer and the light-emitting layer, wherein the material of the hole transport layer is selected from one or more of TPD, poly-TPD, PVK, CBP, NPB, TCTA, mCP, TAPC, and TFB.

[0067] In one embodiment, the quantum dot luminescent material is selected from at least one of single-structure quantum dots and core-shell structure quantum dots. The single-structure quantum dot material is selected from at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdSe ... The group IV-VI compound is selected from at least one of dZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and SnPbTe. At least one of SnPbSSe, SnPbSeTe, and SnPbSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, G At least one of aInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb, wherein the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot includes any one of the above-mentioned single-structure quantum dots, and the shell material of the core-shell quantum dot includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS, and the above-mentioned single-structure quantum dots.

[0068] Compared with traditional methods, the above-mentioned light-emitting devices and their fabrication methods have the following advantages:

[0069] The aforementioned light-emitting device includes an electron transport layer and / or a hole injection layer. The electron transport layer contains an electron transport material and a first additive. The additive has -NH2 and -COOH groups in its molecular structure. When the electron transport material and the additive are mixed, the -COOH groups in the additive molecules bond with metal atoms in the metal oxide and / or doped metal oxide, lowering the LUMO level of the electron transport material and hindering electron injection from the cathode layer to the electron transport layer. Simultaneously, the presence of the -NH2 groups establishes an interfacial dipole at the interface between the electron transport layer and the light-emitting layer. This interfacial dipole further hinders electron injection from the electron transport layer to the light-emitting layer, forming an electron accumulation in the electron transport layer. This reduces the imbalance between the number of holes and electrons in the light-emitting layer, improving device efficiency and stability.

[0070] The hole injection layer contains a hole injection material and a second additive. The molecular structure of the additive has multiple electrophilic groups (-NH2) and multiple proton-philic groups (-C=O). When the hole injection material is mixed with the additive, it can lower the HOMO energy level of the hole injection material, promote hole injection, thereby reducing the imbalance between the number of holes and electrons in the light-emitting layer and improving device efficiency and stability. Attached Figure Description

[0071] Figure 1 This is a schematic diagram of the structure of a light-emitting device according to an embodiment;

[0072] Figure 2 The diagrams show the energy level structure of the light-emitting layer and the electron transport layer. (a) shows the energy level structure of the electron transport layer without additives, and (b) shows the energy level structure of the electron transport layer with additives.

[0073] Figure 3 The diagrams show the energy level structure of the hole injection layer and the hole transport layer, where (a) is the energy level structure of the hole injection layer without additives, and (b) is the energy level structure of the hole injection layer with additives.

[0074] Explanation of reference numerals in the attached figures:

[0075] 100, Light-emitting device; 110, Anode layer; 120, Light-emitting layer; 130, Electron transport layer; 140, Cathode layer; 150, Hole injection layer; 160, Hole transport layer; 170, Substrate. Detailed Implementation

[0076] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0077] It should be noted that when a component is said to be "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0078] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0079] This invention provides a light-emitting device.

[0080] like Figure 1 As shown, a light-emitting device 100 in one embodiment includes an anode layer 110, a light-emitting layer 120, and a cathode layer 140 stacked sequentially. The light-emitting layer 120 contains quantum dot light-emitting material.

[0081] The light-emitting device 100 also includes an electron transport layer 130 and / or a hole injection layer 150.

[0082] The electron transport layer 130 contains an electron transport material and a first additive.

[0083] Hole injection layer 150 contains hole injection material and a second additive.

[0084] The first additive and the second additive are each independently selected from at least one of the following compounds:

[0085]

[0086] R11 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C18 heteroaryl.

[0087] R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1 to C20 alkyl groups;

[0088] R21 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C20 alkyl;

[0089] R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1 to C20 alkyl groups.

[0090] The substituents in R11, R12, R13, R21, and R22 are independently selected from one or more of the following: C1-C10 ester group, C1-C10 amide group, C1-C10 alkoxy group, C1-C10 alkylthio group, C1-C10 alkyl group, C6-C10 aryl group, carboxyl group, mercapto group, phosphono group, phosphonic acid group, amino group, nitro group, cyano group, halogen group, hydroxyl group, and vinyl group.

[0091] The first additive and the second additive can be the same or different.

[0092] In one example, the first additive and the second additive are each independently selected from at least one of ampicillin, amoxicillin, cephalexin and cefaclor, with the following molecular structure.

[0093]

[0094] The aforementioned light-emitting device 100 includes an electron transport layer 130 and / or a hole injection layer 150. The electron transport layer 130 contains an electron transport material and a first additive. The additive has -NH2 and -COOH groups in its molecular structure. When the electron transport material and the additive are mixed, the -COOH groups in the additive molecules bond with metal atoms in the metal oxide and / or doped metal oxide, thereby lowering the LUMO energy level of the electron transport material and hindering electron injection from the cathode layer 140 to the electron transport layer 130. Simultaneously, as... Figure 2 As shown, the presence of the -NH2 group will establish an interfacial dipole at the interface between the electron transport layer 130 and the light-emitting layer 120. The interfacial dipole can further hinder the injection of electrons from the electron transport layer 130 to the light-emitting layer 120, forming an electron accumulation in the electron transport layer 130, thereby reducing the imbalance between the number of holes and electrons in the light-emitting layer 120 and improving the device efficiency and stability.

[0095] Hole injection layer 150 contains hole injection material and a second additive. The molecular structure of the additive has multiple electrophilic groups (-NH2) and multiple proton-philic groups (-C=O). When the hole injection material is mixed with the additive, the HOMO energy level of the hole injection material can be reduced, promoting hole injection, thereby alleviating the imbalance between the number of holes and electrons in the light-emitting layer 120 and improving device efficiency and stability.

[0096] In one example, the electron transport layer 130 has an electron transport material mass fraction of 90%–99% and an additive mass fraction of 1%–10%. In another example, the electron transport layer 130 has an electron transport material mass fraction of 93%–97% and an additive mass fraction of 3%–7%.

[0097] The electron transport material is selected from at least one of metal oxides or doped metal oxides. Optionally, the metal oxide may be, but is not limited to, at least one of ZnO, BaO, TiO2, and SnO2. The doped metal oxide may be, but is not limited to, at least one of ZnO, BaO, TiO2, and SnO2, and the doping element may be, but is not limited to, at least one of Al, Mg, and Li.

[0098] The -COOH group in the additive molecule can bond with metal atoms in metal oxides and / or doped metal oxides, which can reduce the LUMO energy level of the electron transport material and hinder electron injection from the cathode layer to the electron transport layer.

[0099] When the electron transport material and the above-mentioned additives are dissolved together in solvents such as ethanol, the -NH2 groups that are not bonded to the electron transport material will make the mixed solution weakly alkaline, for example, with a pH of 7-7.5, because -COOH is bonded to the metal atoms in the metal oxide and / or the doped metal oxide.

[0100] In one example, the thickness of the electron transport layer 130 is 20nm-80nm.

[0101] In one example, the material of the hole injection layer is selected from at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tin compounds, doped graphene, undoped graphene, and C60.

[0102] Taking PEDOT:PSS as an example, when the hole injection material is mixed with the second additive mentioned above, the electrophilic groups in the second additive molecule will bond with the -SO3 groups in PEDOT:PSS. The addition of the above additive to PEDOT:PSS can reduce the HOMO energy level of PEDOT:PSS, promote hole injection, thereby reducing the imbalance between the number of holes and electrons in the light-emitting layer 120, improving device efficiency and stability. At the same time, the above additive can also effectively reduce the acidity of PEDOT:PSS, thereby improving the lifespan of the device.

[0103] When the hole injection material and the above-mentioned additives are dissolved together in a solvent such as water, the protophilic groups that are not bonded to the hole injection material will make the mixed solution acidic, for example, with a pH value of 3.5-4.5.

[0104] In one example, the mass fraction of the hole injection material in the hole injection layer 150 is 60%-99%, and the mass fraction of the second additive in the hole injection layer is 1%-40%. More preferably, the mass fraction of the hole injection material in the hole injection layer 150 is 65%-90%, and the mass fraction of the second additive in the hole injection layer is 10%-35%.

[0105] In one example, the hole injection layer 150 has a thickness of 10nm-100nm.

[0106] The anode layer 110 is made of conductive materials, such as high work function metals and metal oxides like ITO, IZO, and Au.

[0107] In one example, the thickness of the anode layer 110 is 10nm-200nm.

[0108] The cathode layer 140 is made of conductive materials, such as Al, Ag, MgAg alloys, etc.

[0109] In one example, the thickness of the cathode layer 140 is 10nm-200nm.

[0110] The quantum dot luminescent material is selected from at least one of single-structure quantum dots and core-shell structure quantum dots. The single-structure quantum dot material is selected from at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. Specifically, the group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, and CdZnSe. At least one of the following groups: nTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the group IV-VI compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and SnPbSS. e, SnPbSeTe, and SnPbSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaIn The quantum dot contains at least one of NAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb, wherein the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot includes any one of the above-mentioned single-structure quantum dots, and the shell material of the core-shell quantum dot includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS, and the above-mentioned single-structure quantum dots.

[0111] Understandably, organic ligands can also be bound to quantum dot luminescent materials. The organic ligands can be selected from, but are not limited to, at least one of OA (oleic acid), OAM (oleylamine), and TOP (trioctylphosphine).

[0112] In one example, the thickness of the light-emitting layer 120 is 10nm-50nm.

[0113] In one example, the light-emitting device 100 also includes a hole transport layer 160 disposed between the hole injection layer 150 and the light-emitting layer 120.

[0114] Among the above-mentioned additive molecules, such as Figure 3 As shown, the presence of proton-loving groups establishes an interface dipole at the interface between the hole injection layer 150 and the hole transport layer 160. The interface dipole promotes hole injection and forms a hole accumulation in the hole injection layer 150, thereby reducing the imbalance between the number of holes and electrons in the light-emitting layer 120 and improving device efficiency and stability.

[0115] Optionally, the material of the hole transport layer 160 may be any one or a mixture of TPD, poly-TPD, PVK, CBP, NPB, TCTA, mCP, TAPC, and TFB.

[0116] In one example, the hole transport layer 160 has a thickness of 10nm-100nm.

[0117] Understandably, the display device also includes a substrate 170. Figure 1 The light-emitting device 100 shown is a positively positioned device, with an anode layer 110 disposed on a substrate 170. Specifically, the light-emitting device 100 includes a substrate 170, an anode layer 110, a hole injection layer 150, a hole transport layer 160, a light-emitting layer 120, an electron transport layer 130, and a cathode layer 140 stacked sequentially. For an inverted device, the cathode layer 140 is disposed on the substrate 170, and the device structure, for example, includes a substrate 170, a cathode layer 140, an electron transport layer 130, a light-emitting layer 120, a hole transport layer 160, a hole injection layer 150, and an anode layer 110 stacked sequentially.

[0118] The substrate 170 includes a substrate and a TFT driving array disposed on the substrate. The substrate can be a rigid substrate, such as a glass substrate, preferably a silicon-based substrate with good thermal conductivity, or a flexible substrate, such as a PI (polyimide) substrate.

[0119] The present invention provides a method for manufacturing a light-emitting device 100 according to any of the above examples.

[0120] A method for manufacturing a light-emitting device 100 according to one embodiment includes the following steps:

[0121] A cathode layer is fabricated on the substrate;

[0122] An electron transport layer is fabricated on the cathode layer;

[0123] A light-emitting layer is fabricated on the electron transport layer;

[0124] A hole injection layer is fabricated on the light-emitting layer;

[0125] A light-emitting layer is prepared on the hole injection layer;

[0126] An anode layer is fabricated on the light-emitting layer to obtain the light-emitting device.

[0127] or,

[0128] An anode layer is fabricated on the substrate;

[0129] A hole injection layer is fabricated on the anode layer;

[0130] A light-emitting layer is fabricated on the hole injection layer;

[0131] An electron transport layer is fabricated on the light-emitting layer;

[0132] A cathode layer is fabricated on the electron transport layer to obtain the light-emitting device;

[0133] The light-emitting layer contains quantum dot light-emitting material;

[0134] Preferably, the electron transport layer contains an electron transport material and a first additive.

[0135] And / or, the hole injection layer contains a hole injection material and a second additive.

[0136] In one example, the steps to create the electron transport layer include:

[0137] The electron transport material and the above-mentioned additives are mixed and dissolved in a solvent to obtain ink;

[0138] The ink is coated onto the cathode layer or the light-emitting layer and then dried to form a film.

[0139] The solvent may be one or more of ethanol, ethylene glycol, and 3-methoxybutanol, but is not limited to.

[0140] The coating method can be, but is not limited to, spraying, spin coating, scraping, and inkjet printing.

[0141] Similarly, the hole injection layer can also be fabricated using the same method as the electron transport layer described above.

[0142] Specific embodiments are provided below to illustrate the present invention, but the present invention is not limited to the following embodiments. It should be understood that the appended claims summarize the scope of the present invention, and those skilled in the art, guided by the inventive concept, should realize that any changes made to the various embodiments of the present invention will be covered by the spirit and scope of the claims.

[0143] Example 1

[0144] The light-emitting device in this embodiment includes a substrate, an anode layer, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode layer stacked sequentially.

[0145] The method for manufacturing a light-emitting device includes the following steps:

[0146] Step 1: Provide a glass substrate and deposit ITO on the glass substrate to form an anode layer.

[0147] Step 2: Fabricate a hole injection layer on the anode layer. Spin-coat an ink containing PEDOT:PSS onto the anode layer, dry it to form a film, and then anneal it at 150°C for 15 minutes to form a hole injection layer with a thickness of 45 nm.

[0148] Step 3: Fabricate a hole transport layer on the hole injection layer. Spin-coat the hole injection layer with TFB-containing ink, dry it to form a film, and then anneal it at 230°C for 30 min to form a hole transport layer with a thickness of 20 nm.

[0149] Step 4: Fabricate the luminescent layer on the hole transport layer. Using CdSe / ZnS red quantum dots with OA (oleic acid) as the organic ligand, spin-coat the red quantum dot ink onto the hole transport layer. After drying to form a film, anneal at 100°C for 10 min to form a luminescent layer with a thickness of 15 nm.

[0150] Step 5: Fabricate an electron transport layer on the aforementioned luminescent layer. Dissolve ZnO and ampicillin in ethanol at a mass ratio of 95:5 to prepare an ink with a pH of 7.3. Spin-coat the ink onto the luminescent layer, dry it to form a film, and then anneal it at 100°C for 10 minutes to form an electron transport layer with a thickness of 30 nm.

[0151] Step 6: An Ag layer is deposited on the electron transport layer to form a cathode layer with a thickness of 150 nm.

[0152] Step 7: Encapsulation to obtain the light-emitting device.

[0153] The entire process was carried out in a glove box under nitrogen protection.

[0154] Example 2

[0155] This embodiment is basically the same as the steps in Embodiment 1, except that in step 5, amoxicillin is used instead of ampicillin in Embodiment 1.

[0156] Example 3

[0157] This embodiment is basically the same as the steps in Embodiment 1, except that in step 5, cephalexin is used instead of ampicillin in Embodiment 1 as the additive.

[0158] Example 4

[0159] This embodiment is basically the same as the steps in Embodiment 1, except that in step 5, cefaclor is used instead of ampicillin in Embodiment 1 as the additive.

[0160] Example 5

[0161] This embodiment is basically the same as the steps in Embodiment 1, except that: in step 2, the additive ampicillin is used, and the mass ratio of PEDOT:PSS to ampicillin is 8:2; and in step 5, no additive is used.

[0162] Example 6

[0163] This embodiment is basically the same as the steps in Embodiment 1, except that: in step 2, the additive amoxicillin is used, and the mass ratio of PEDOT:PSS to amoxicillin is 8:2; and in step 5, no additive is used.

[0164] Example 7

[0165] This embodiment is basically the same as the steps in Embodiment 1, except that: in step 2, cefalexin is used as an additive, and the mass ratio of PEDOT:PSS to cefalexin is 8:2; in step 5, no additive is used.

[0166] Example 8

[0167] This embodiment is basically the same as the steps in Embodiment 1, except that: in step 2, cefaclor is used as an additive, and the mass ratio of PEDOT:PSS to cefaclor is 8:2; in step 5, no additive is used.

[0168] Example 9

[0169] This embodiment is basically the same as the steps in Embodiment 1, except that: in step 2, the additive ampicillin is used, and the mass ratio of PEDOT:PSS to ampicillin is 8:2.

[0170] Comparative Example 1

[0171] This embodiment is basically the same as the steps in Embodiment 1, except that no additives are used in step 5.

[0172] The entire process was carried out in a glove box under nitrogen protection.

[0173] The light-emitting devices fabricated in Examples 1-4 and Comparative Example 1 were subjected to performance tests, including external quantum efficiency, current efficiency, and lifetime (T95@1000nit). The test results are shown in Table 1.

[0174] Table 1 Performance test results of light-emitting devices

[0175]

[0176]

[0177] The devices in Examples 1-4 had additives added to the electron transport layer, the devices in Examples 5-8 had additives added to the hole injection layer, and the device in Example 9 had additives added to both the electron transport layer and the hole injection layer. As shown in Table 1, the comparison of external quantum efficiency and current efficiency is: Example 9 > Examples 1-4 > Examples 5-8 > Comparative Example. Since current efficiency and lifetime are generally positively correlated, higher current efficiency is better, and longer lifetime is better; the comparison of device lifetime is also basically the same as above.

[0178] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0179] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A light-emitting device, characterized in that, It includes an anode layer, a light-emitting layer, and a cathode layer stacked sequentially, wherein the light-emitting layer contains quantum dot light-emitting material; The light-emitting device further includes an electron transport layer disposed between the light-emitting layer and the cathode layer. The electron transport layer contains an electron transport material and a first additive. The first additive hinders electron injection from the cathode layer to the electron transport layer. The electron transport material is selected from at least one of metal oxides or doped metal oxides. The first additive is selected from at least one of the following compounds: or , R11 is selected from: substituted or unsubstituted C6-C18 aryl groups, substituted or unsubstituted C1-C10 alkyl groups; R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1~C10 alkyl groups; R21 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C10 alkyl; R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1~C10 alkyl groups; The substituents are independently selected from one or more of the following: C1-C10 ester group, C1-C10 amide group, C1-C10 alkoxy group, C1-C10 alkylthio group, C1-C10 alkyl group, C6-C10 aryl group, carboxyl group, mercapto group, phosphono group, phosphonic acid group, amino group, nitro group, cyano group, halogen group, hydroxyl group, and vinyl group.

2. The light-emitting device as described in claim 1, characterized in that, The light-emitting device further includes a hole injection layer disposed between the light-emitting layer and the anode layer, the hole injection layer containing a hole injection material and a second additive, the second additive promoting hole injection, the second additive being selected from at least one of the following compounds: or , R11 is selected from: substituted or unsubstituted C6-C18 aryl groups, substituted or unsubstituted C1-C10 alkyl groups; R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1~C10 alkyl groups; R21 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C10 alkyl; R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1~C10 alkyl groups; The substituents are independently selected from one or more of the following: C1-C10 ester group, C1-C10 amide group, C1-C10 alkoxy group, C1-C10 alkylthio group, C1-C10 alkyl group, C6-C10 aryl group, carboxyl group, mercapto group, phosphono group, phosphonic acid group, amino group, nitro group, cyano group, halogen group, hydroxyl group, and vinyl group.

3. The light-emitting device as described in claim 1 or 2, characterized in that, R11 is selected from: substituted or unsubstituted C6-C10 aryl groups; R12 and R13 are each independently selected from: substituted or unsubstituted C1~C10 alkyl groups; R21 is selected from: substituted or unsubstituted C6-C10 aryl groups; R22 is selected from: halogen, carboxyl, hydroxyl, substituted or unsubstituted C1~C10 alkyl.

4. The light-emitting device as described in claim 3, characterized in that, R11 is selected from: phenyl, naphthyl, 2-methylphenyl, 2-methylnaphthyl; R12 and R13 are independently selected from: methyl, ethyl, n-propyl, and isopropyl, respectively; R21 is selected from: phenyl, naphthyl, 2-methylphenyl, 2-methylnaphthyl; R22 is selected from: halogen, carboxyl, hydroxyl, substituted or unsubstituted C1~C10 alkyl.

5. The light-emitting device as described in claim 1, characterized in that, The first additive is selected from at least one of the following compounds: 、 、 、 。 6. The light-emitting device as described in claim 2, characterized in that, The second additive is selected from at least one of the following compounds: 、 、 、 。 7. The light-emitting device as described in any one of claims 1, 2, and 4, characterized in that, The metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2.

8. The light-emitting device as described in claim 7, characterized in that, The metal oxide in the doped metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2, and the doping element is selected from at least one of Al, Mg and Li.

9. The light-emitting device as described in any one of claims 1, 2, and 4, characterized in that, The electron transport material has a mass fraction of 90% to 99% in the electron transport layer, and the first additive has a mass fraction of 1% to 10% in the electron transport layer.

10. The light-emitting device as described in claim 9, characterized in that, The electron transport material has a mass fraction of 93%-97% in the electron transport layer, and the first additive has a mass fraction of 3%-7% in the electron transport layer.

11. The light-emitting device as described in claim 2, characterized in that, The material of the hole injection layer is selected from at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tin compounds, doped graphene, undoped graphene, and C60.

12. The light-emitting device as described in claim 2, characterized in that, The hole injection material has a mass fraction of 60%-99% in the hole injection layer, and the second additive has a mass fraction of 1%-40% in the hole injection layer.

13. The light-emitting device as described in claim 12, characterized in that, The hole injection material has a mass fraction of 65% to 90% in the hole injection layer, and the second additive has a mass fraction of 10% to 35% in the hole injection layer.

14. The light-emitting device as described in claim 2, characterized in that, The light-emitting device further includes a hole transport layer disposed between the hole injection layer and the light-emitting layer, wherein the material of the hole transport layer is selected from one or more of TPD, poly-TPD, PVK, CBP, NPB, TCTA, mCP, TAPC and TFB; The quantum dot luminescent material is selected from at least one of single-structure quantum dots and core-shell structure quantum dots. The single-structure quantum dot material is selected from at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. Specifically, the group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, and Cd... ZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the IV-VI compound is selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbS At least one of Se, SnPbSeTe, and SnPbSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaIn The quantum dot contains at least one of NAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb, wherein the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot includes any one of the above-mentioned single-structure quantum dots, and the shell material of the core-shell quantum dot includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS, and the above-mentioned single-structure quantum dots.

15. A method for manufacturing a light-emitting device, characterized in that, Includes the following steps: A cathode layer is fabricated on the substrate; An electron transport layer is fabricated on the cathode layer; A light-emitting layer is fabricated on the electron transport layer; A hole injection layer is fabricated on the light-emitting layer; An anode layer is fabricated on the hole injection layer to obtain the light-emitting device; or, An anode layer is fabricated on the substrate; A hole injection layer is fabricated on the anode layer; A light-emitting layer is fabricated on the hole injection layer; An electron transport layer is fabricated on the light-emitting layer; A cathode layer is fabricated on the electron transport layer to obtain the light-emitting device; The light-emitting layer contains quantum dot light-emitting material; The electron transport layer contains an electron transport material and a first additive, wherein the electron transport material is selected from at least one of metal oxides or doped metal oxides, and the first additive hinders electron injection from the cathode layer to the electron transport layer. The first additive is selected from at least one of the following compounds: or , R11 is selected from: substituted or unsubstituted C6-C18 aryl groups, substituted or unsubstituted C1-C10 alkyl groups; R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1~C10 alkyl groups; R21 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C10 alkyl; R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1~C10 alkyl groups; The substituents are independently selected from one or more of the following: C1-C10 ester group, C1-C10 amide group, C1-C10 alkoxy group, C1-C10 alkylthio group, C1-C10 alkyl group, C6-C10 aryl group, carboxyl group, mercapto group, phosphono group, phosphonic acid group, amino group, nitro group, cyano group, halogen group, hydroxyl group, and vinyl group.

16. The method for manufacturing a light-emitting device as described in claim 15, characterized in that, The hole injection layer contains a hole injection material and a second additive, the second additive promoting hole injection, and the second additive is selected from at least one of the following compounds: or , R11 is selected from: substituted or unsubstituted C6-C18 aryl groups, substituted or unsubstituted C1-C10 alkyl groups; R12 and R13 are each independently selected from: hydrogen, halogen, substituted or unsubstituted C1~C10 alkyl groups; R21 is selected from: hydrogen, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C1-C10 alkyl; R22 is selected from: hydrogen, halogen, carboxyl, hydroxyl, substituted or unsubstituted C1~C10 alkyl groups; The substituents are independently selected from one or more of the following: C1-C10 ester group, C1-C10 amide group, C1-C10 alkoxy group, C1-C10 alkylthio group, C1-C10 alkyl group, C6-C10 aryl group, carboxyl group, mercapto group, phosphono group, phosphonic acid group, amino group, nitro group, cyano group, halogen group, hydroxyl group, and vinyl group.

17. The method for manufacturing a light-emitting device as described in claim 15 or 16, characterized in that, The metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2.

18. The method for manufacturing a light-emitting device as described in claim 17, characterized in that, The metal oxide in the doped metal oxide is selected from at least one of ZnO, BaO, TiO2 and SnO2, and the doping element is selected from at least one of Al, Mg and Li.

19. The method for manufacturing a light-emitting device as described in claim 18, characterized in that, The electron transport material has a mass fraction of 90-99% in the electron transport layer, and the first additive has a mass fraction of 1%-10% in the electron transport layer.

20. The method for manufacturing a light-emitting device as described in claim 19, characterized in that, The electron transport material has a mass fraction of 93%-97% in the electron transport layer, and the first additive has a mass fraction of 3%-7% in the electron transport layer.

21. The method for manufacturing a light-emitting device as described in claim 16, characterized in that, The material of the hole injection layer is selected from at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tin compounds, doped graphene, undoped graphene, and C60.

22. The method for manufacturing a light-emitting device as described in claim 21, characterized in that, The hole injection material has a mass fraction of 60%-99% in the hole injection layer, and the second additive has a mass fraction of 1%-40% in the hole injection layer.

23. The method for manufacturing a light-emitting device as described in claim 22, characterized in that, The hole injection material has a mass fraction of 65% to 90% in the hole injection layer, and the second additive has a mass fraction of 10% to 35% in the hole injection layer.

24. The method for manufacturing a light-emitting device as described in claim 16, characterized in that, The light-emitting device further includes a hole transport layer disposed between the hole injection layer and the light-emitting layer, wherein the material of the hole transport layer is selected from one or more of TPD, poly-TPD, PVK, CBP, NPB, TCTA, mCP, TAPC and TFB; The quantum dot luminescent material is selected from at least one of single-structure quantum dots and core-shell structure quantum dots. The single-structure quantum dot material is selected from at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. Specifically, the group II-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, and Cd... ZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the IV-VI compound is selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbS At least one of Se, SnPbSeTe, and SnPbSTe, wherein the III-V compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaIn The quantum dot contains at least one of NAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb, wherein the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2, and AgInS2; the core of the core-shell quantum dot includes any one of the above-mentioned single-structure quantum dots, and the shell material of the core-shell quantum dot includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS, and the above-mentioned single-structure quantum dots.

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