Photoelectric device, preparation method thereof and display device

Abstract

The invention discloses a photoelectric device and a preparation method thereof and a display device, the photoelectric device comprises an anode, a hole function layer, a transition layer, an optical function layer and a cathode which are stacked in sequence, the hole transmission layer comprises a first P-type semiconductor material, and the transition layer comprises a second P-type semiconductor material and a first quantum dot. According to the photoelectric device, the transition layer comprising the second P-type semiconductor material and the first quantum dots is arranged between the hole transmission layer and the optical function layer, and the transition layer is used as a buffer interface between the hole transmission layer and the optical function layer, so that the service life of the photoelectric device can be effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a photoelectric device, a preparation method thereof and a display device. BACKGROUND

[0002] The photoelectric devices widely used at present are organic photoelectric devices (OLED) and quantum dot photoelectric devices (QLED). OLED has become the mainstream technology in the field of display technology due to its excellent display performance such as self-luminous, simple structure, ultra-thin, fast response, wide viewing angle, low power consumption, flexible display and the like. QLED has the advantages of saturated color, adjustable wavelength, low turn-on voltage, good solution processing, easy fine control of quantum dots, high photoelectric and electroluminescent quantum yield, and has become a strong competitor of OLED in recent years.

[0003] The traditional OLED and QLED device structure generally includes an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode. Under the action of an electric field, the holes generated by the anode and the electrons generated by the cathode move and are injected into the hole transport layer and the electron transport layer, respectively, and finally migrate to the light-emitting layer. When the two meet in the light-emitting layer, an energy excitation is generated, thereby exciting the light-emitting molecules to finally produce visible light.

[0004] The service life of the existing photoelectric device is short and needs to be further improved. SUMMARY

[0005] In view of this, the present application provides a photoelectric device, aiming at improving the problem of short service life of the existing photoelectric device.

[0006] In a first aspect, the present application provides a photoelectric device, comprising an anode, a hole functional layer, a transition layer, a light functional layer and a cathode which are stacked in sequence, wherein the hole functional layer comprises a first P-type semiconductor material, and the transition layer comprises a second P-type semiconductor material and a first quantum dot.

[0007] Optionally, in some embodiments, the hole functional layer is a hole transport layer; and / or

[0008] The light functional layer comprises a second quantum dot.

[0009] Optionally, in some embodiments, the LUMO energy level of the second P-type semiconductor material is greater than or equal to the LUMO energy level of the first P-type semiconductor material; and / or

[0010] The absolute value of the HOMO energy level of the first P-type semiconductor material is greater than or equal to 2.5 eV; and / or

[0011] the HOMO energy level of the first P-type semiconductor material is -4.8 to -5.5 eV; and / or

[0012] the HOMO energy level of the second P-type semiconductor material ranges from the HOMO energy level of the first P-type semiconductor material to -6.0 eV.

[0013] Optionally, in some embodiments, the total thickness of the hole functional layer and the transition layer is 10 to 50 nm; and / or

[0014] the thickness of the transition layer is 5 to 15 nm; and / or

[0015] the thickness of the light functional layer is 10 to 50 nm; and / or

[0016] the content of the first quantum dots in the transition layer is 1 to 10 wt%; and / or

[0017] the average particle size of the first quantum dots is 2 to 15 nm; and / or

[0018] the average particle size of the second quantum dots is 7 to 15 nm; and / or

[0019] the surface of the first quantum dots is connected with ligands, and the ligands are selected from fluorine-containing ligands, and the fluorine-containing ligands include one or more of trifluoroacetic acid, fluorine-containing mercaptoacetic acid, and fluorine-containing thiol; and / or

[0020] the surface of the second quantum dots is connected with ligands, and the ligands are selected from fluorine-containing ligands, and the fluorine-containing ligands include one or more of trifluoroacetic acid, fluorine-containing mercaptoacetic acid, and fluorine-containing thiol.

[0021] Optionally, in some embodiments, the first P-type semiconductor material includes one or more of a first P-type organic semiconductor material and a first P-type inorganic semiconductor material, and the second P-type semiconductor material includes one or more of a second P-type organic semiconductor material and a second P-type inorganic semiconductor material.

[0022] Optionally, in some embodiments, the first P-type organic semiconductor material and the second P-type organic semiconductor material comprise one or more of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(N,N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec- butylphenyl)benzidine)], poly(N-vinylcarbazole) and its derivatives, poly(phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene], polyaniline, polythiophene, polypyrrole, fluorene-aniline copolymer, polyfluorene, poly(p-phenylenevinylene), PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, PEDOT, PEDOT:PSS, derivatives of PEDOT:PSS doped with s-MoO3; and / or

[0023] The first P-type inorganic semiconductor material and the second P-type inorganic semiconductor material comprise one or more of first doped metal oxide particles, first non-doped metal oxide particles, metal sulfides, and metal nitrides, wherein the metal oxide in the first doped metal oxide particles and the metal oxide in the first non-doped metal oxide particles each independently comprise one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the first doped metal oxide particles comprises one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfides comprise one or more of CuS, MoS3, WS3, and the metal nitrides comprise P-type gallium nitride; and / or

[0024] The first P-type semiconductor material is the same as or different from the second P-type semiconductor material.

[0025] Optionally, in some embodiments, each of the first and second quantum dots is independently selected from one or more of a single-structure quantum dot, a core-shell quantum dot having one or more shell layers, and a perovskite quantum dot, each of the material of the single-structure quantum dot, the core material of the core-shell quantum dot, and the shell material of the core-shell quantum dot independently comprising one or more of a II-VI compound, a IV-VI compound, a III-V compound, and a I-III-VI compound, the II-VI compound comprising one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, the IV-VI compound comprising one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, the III-V compound comprising one or more of 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, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, the I-III-VI compound comprising one or more of CuInS2, CuInSe2, and AgInS2, the perovskite quantum dot comprising a doped or undoped inorganic perovskite semiconductor or an organic-inorganic hybrid perovskite semiconductor, the inorganic perovskite semiconductor having a general structure of AMX3, where A is cesium, M comprises one or more of lead, tin, copper, nickel, cadmium, cadmium, manganese, cobalt, iron, chromium, ytterbium, europium, and X is a halogen.one or more of iodine, wherein B comprises CH3(CH2), n-2 NH3or [NH3(CH2) n NH3], wherein n > 2, M' comprises one or more of lead, tin, copper, nickel, cadmium, cadmium, manganese, cobalt, iron, chromium, ytterbium, europium, and X' is a halogen comprising one or more of chlorine, bromine, iodine; and / or

[0026] The first quantum dot is the same as or different from the second quantum dot.

[0027] Optionally, in some embodiments, the anode and the cathode independently comprise a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal element electrode, or an alloy electrode, the doped metal oxide particle electrode comprises one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, and aluminum-doped magnesium oxide, the composite electrode comprises one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, or ZnS / Al / ZnS, the metal element electrode comprises one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg, and Ba; and / or

[0028] The optoelectronic device further comprises a hole injection layer between the anode and the hole functional layer, the hole injection layer comprises one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s-MoO3, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide;

[0029] The optoelectronic device further includes an electron transport layer located between the optical functional layer and the cathode. The electron transport layer is made of one or more inorganic and organic electron transport materials. The inorganic electron transport material includes one or more of a second-doped metal oxide particle, a second-undoped metal oxide particle, a group IIB-VIA semiconductor material, a group IIIA-VA semiconductor material, and a group IB-IIIA-VIA semiconductor material. The second-undoped metal oxide particle is made of one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxide in the second-doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping element in the second-doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The group IIB-VIA semiconductor material includes one or more of ZnS, ZnSe, and CdS. The group IIIA-VA semiconductor material includes InP and GaP. One or more of the following, wherein the IB-IIIA-VIA group semiconductor materials include one or more of CuInS and CuGaS; the organic electron transport materials include 8-hydroxyquinoline aluminum, diphenyl[4-(triphenylsilyl)phenyl]phosphine, 1,3,5-tris((3-pyridyl)-3-phenyl)benzene, 2-(4-biphenyl)-5-phenyloxadiazole, bis(10-hydroxybenzo[h]quinoline)beryllium, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, and 2,7-bis(diphenylphosphine)-9,9 One or more of the following: '-spirobis[fluorene], 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 4,6-bis(3,5-di(3-pyridinylphenyl)-2-methylpyrimidine, 4,7-diphenyl-1,10-phenanthroline, 2-(4'-tert-butylphenyl)-5-(4'-biphenyl)-1,3,4-oxadiazole, 2,9-dimethyl-4,7-diphenyl-1,10-o-diazaphenanthroline, 4,7-diphenyl-1,10-o-diazaphenanthroline, and bis(2-methyl-8-hydroxyquinoline-N1,O8)-1,1'-biphenyl-4-hydroxy)aluminum.

[0030] Secondly, embodiments of this application also provide a method for fabricating an optoelectronic device, comprising the following steps:

[0031] Provide a photoelectric device preform, the photoelectric device preform including an anode;

[0032] A first P-type semiconductor material is provided, and the first P-type semiconductor material is disposed on the anode to obtain a hole functional layer;

[0033] A second P-type semiconductor material, quantum dots, and a solvent are provided and mixed to obtain a mixed solution. The mixed solution is then placed on the hole functional layer and subjected to heat treatment to obtain a transition layer and an optical functional layer sequentially stacked on the hole functional layer. The transition layer includes a second P-type semiconductor material and a first quantum dot, and the optical functional layer includes a second quantum dot.

[0034] A cathode is placed on the optical functional layer to obtain an optoelectronic device.

[0035] Optionally, in some embodiments, the hole functional layer is a hole transport layer; and / or

[0036] The heat treatment temperature is 50–150°C; and / or

[0037] The heat treatment time is 5 to 30 minutes; and / or

[0038] The quantum dots are surface-attached with ligands selected from fluorinated ligands, including one or more of trifluoroacetic acid, fluorinated thioglycolic acid, and fluorinated thiols; and / or

[0039] The solvent includes one or more of toluene, benzene, chlorobenzene, xylene, chloroform, acetone, n-octane, isooctane, cyclohexane, n-hexane, n-pentane, and isopentane.

[0040] Thirdly, embodiments of this application also provide a display device, including the aforementioned optoelectronic device.

[0041] The optoelectronic device described in this application has a transition layer comprising a second P-type semiconductor material and a first quantum dot between the hole functional layer and the optical functional layer. Using the transition layer as a buffer interface between the hole functional layer and the optical functional layer can improve the lifetime of the optoelectronic device. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of an optoelectronic device provided in an embodiment of this application;

[0044] Figure 2 This is a schematic diagram of another optoelectronic device provided in an embodiment of this application;

[0045] Figure 3This is a schematic diagram of the structure of another optoelectronic device provided in the embodiments of this application;

[0046] Figure 4 This is a flowchart of a method for fabricating an optoelectronic device according to an embodiment of this application.

[0047] Figure label:

[0048] Optoelectronic device 100; anode 10; hole functional layer 20; transition layer 30; optical functional layer 40; cathode 50; hole injection layer 60; electron transport layer 70. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0050] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0051] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0052] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0053] In this application, the term "on" forming another layer on a certain layer is a broad concept. It can mean that the formed other layer is adjacent to a certain layer, or it can mean that there are other spacer structures between the other layer and the certain layer. For example, when a first cathode is formed "on" a first carrier functional layer, the term "on" can mean that the formed first cathode is adjacent to the first carrier functional layer, or it can mean that there are other spacer structures between the first cathode and the first carrier functional layer, such as an optical functional layer.

[0054] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0055] Optoelectronic devices require the injection of electrons and holes to operate. The simplest optoelectronic device consists of a cathode, an electron transport layer, an optical functional layer, a hole transport layer, and an anode. In an optoelectronic device, the optical functional layer is sandwiched between the charge transport layers. When a forward bias is applied to both ends of the optoelectronic device, electrons and holes enter the optical functional layer through the electron transport layer and hole transport layer, respectively, and recombine to emit light in the optical functional layer. High-performance optoelectronic devices are organic-inorganic composite devices, meaning that the hole injection layer material and the hole transport layer material are organic materials, while the electron injection layer material and the electron transport layer material are inorganic materials. A key characteristic is that the electron mobility of inorganic nanoparticles is much greater than that of holes. This leads to the accumulation of charge at the interface between the hole transport layer and the optical functional layer, forming a built-in electric field. Furthermore, some electrons may jump to the hole transport layer, causing degradation of the hole transport layer material and consequently, a decrease in device performance.

[0056] The technical solution of this application is as follows:

[0057] Firstly, please refer to Figure 1 This application provides an optoelectronic device 100, comprising an anode 10, a hole functional layer 20, a transition layer 30, a light functional layer 40, and a cathode 50 stacked sequentially. The hole functional layer 20 includes a first P-type semiconductor material, the transition layer 30 includes a second P-type semiconductor material and a first quantum dot, and the light functional layer 40 includes a second quantum dot.

[0058] In some embodiments, the hole functional layer is a hole transport layer.

[0059] The optoelectronic device 100 described in this application has a transition layer 30 comprising a second P-type semiconductor material and a first quantum dot disposed between the hole functional layer 20 and the optical functional layer 40. This transition layer 30 serves as a buffer interface between the hole functional layer 20 and the optical functional layer 40. Thus, leakage electrons that jump over the optical functional layer 40 first enter the transition layer 30 and recombine with holes in the transition layer 30 to form excitons, and then transfer to the quantum dot optical functional layer via energy resonance transfer. This effectively reduces the damage to the first P-type semiconductor material in the hole functional layer 20 caused by leakage electrons. Therefore, the hole transport efficiency of the optoelectronic device 100 can be effectively improved, hole-electron balance in the optical functional layer 40 can be promoted, and the accumulation of electrons between the hole functional layer 20 and the optical functional layer 40 can be prevented from forming a built-in electric field. This also prevents the degradation of the hole functional material caused by electrons jumping to the hole functional layer 20, thereby effectively improving the luminous efficiency and lifetime of the optoelectronic device 100.

[0060] The LUMO energy level of the second P-type semiconductor material is greater than or equal to the LUMO energy level of the first P-type semiconductor material, that is, LUMO 第二P型半导体材料 ≥LUMO 第一P型半导体材料 Thus, the LUMO energy level of the second P-type semiconductor material in the transition layer 30 is shallower, which can more effectively block electrons from being transported to the hole functional layer 20, further reducing the damage of leakage electrons to the first P-type semiconductor material in the hole functional layer 20, and further improving the stability of the device.

[0061] In some embodiments, the absolute value of the HOMO energy level of the first p-type semiconductor material is greater than or equal to 2.5 eV, that is, |HOMO 第一P型半导体材料 |≥2.5eV. In this way, the HOMO energy level of the second P-type semiconductor material can be between the HOMO energy level of the first P-type semiconductor material and the HOMO energy level of the quantum dot, which is beneficial for hole injection into the optical functional layer 40, thereby improving the hole injection efficiency of the device and improving the device's efficiency and lifetime performance.

[0062] In some embodiments, the HOMO energy level of the first P-type semiconductor material is -4.8 to -5.5 eV, such as -4.8 eV, -4.9 eV, -5.0 eV, -5.1 eV, -5.2 eV, -5.3 eV, -5.4 eV, -5.5 eV, etc.

[0063] In some embodiments, the HOMO energy level range of the second P-type semiconductor material is from the HOMO energy level of the first P-type semiconductor material to -6.0 eV. For example, when the HOMO energy level of the first P-type semiconductor material is -5.0 eV, the HOMO energy level range of the second P-type semiconductor material can be from -5.0 eV to -6.0 eV. This can more effectively improve the hole injection efficiency of the device and block electron transport to the hole functional layer 20, further reducing the damage of leakage electrons to the first P-type semiconductor material in the hole functional layer 20, and further improving the stability and lifetime of the device.

[0064] It should be noted that the determination method for the HOMO and LUMO energy levels in this application is as follows: Using TD-DFT (time-dependent density functional theory) via Gaussian 09W (Gaussian Inc.), the molecular geometry is first optimized using the semi-empirical method "Ground State / Semi-empirical / Default Spin / AM1" (Charge 0 / Spin Singlet). Then, the energy structure of the organic molecule is calculated using TD-DFT (time-dependent density functional theory) to obtain "TD-SCF / DFT / DefaultSpin / B3PW91" and the basis set "6-31G(d)" (Charge 0 / Spin Singlet). The HOMO and LUMO energy levels are calculated according to the following calibration formula:

[0065] HOMO(eV)=((HOMO(G)×27.212)-0.9899) / 1.1206;

[0066] LUMO(eV)=((LUMO(G)×27.212)-2.0041) / 1.385.

[0067] The first P-type semiconductor material can be one or more of a first P-type organic semiconductor material and a first P-type inorganic semiconductor material, and the second P-type semiconductor material can be one or more of a second P-type organic semiconductor material and a second P-type inorganic semiconductor material.

[0068] The first P-type organic semiconductor material and the second P-type organic semiconductor material can each be independently selected from, but not limited to, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(N,N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (Poly-TPD), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), poly(N-vinylcarbazole) (PVK) and its derivatives, poly(phenylenevinylene) (PPV), and poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene] The following are included in the list of poly[MEH-PPV], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MOMO-PPV), polyaniline, polythiophene, polypyrrole, fluorene-aniline copolymer, polyfluorene, poly(p)phenylenevinylene, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, PEDOT (poly3,4-ethylenedioxythiophene), PEDOT:PSS, and PEDOT:PSS derivatives doped with s-MoO3 (PEDOT:PSS:s-MoO3).

[0069] The first P-type inorganic semiconductor material and the second P-type inorganic semiconductor material may each be independently selected from, but not limited to, one or more of the following: first doped metal oxide particles, first undoped metal oxide particles, metal sulfides, and metal nitrides. Specifically, the metal oxides in the first doped metal oxide particles and the metal oxides in the first undoped metal oxide particles may each independently include, but are not limited to, one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5; the doping elements in the first doped metal oxide particles may include, but are not limited to, one or more of Mo, W, Ni, Cr, Cu, and V; the metal sulfides may include, but are not limited to, one or more of CuS, MoS3, and WS3; and the metal nitrides may include, but are not limited to, P-type gallium nitride.

[0070] It is understood that the first P-type semiconductor material and the second P-type semiconductor material may be the same or different. In at least one embodiment, the first P-type semiconductor material and the second P-type semiconductor material are the same.

[0071] In some embodiments, the total thickness of the hole functional layer 20 and the transition layer 30 is 10–50 nm, for example, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc. In some embodiments, the thickness of the transition layer 30 is 5–15 nm, for example, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 13 nm, 15 nm, etc. Within this thickness range, leakage current can be effectively avoided, which helps to balance the charge carriers of the device.

[0072] In some embodiments, the content of the first quantum dot in the transition layer 30 is 1–10 wt%, for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, etc. Within this content range, hole carrier injection and energy transfer can be effectively carried out, while leakage current damage to the hole functional layer 20 can be effectively avoided, thus fully utilizing the role of the buffer interface.

[0073] In some embodiments, the average particle size of the first quantum dot is 2 to 15 nm, and in at least one embodiment, the average particle size of the first quantum dot is 7 to 15 nm.

[0074] In some embodiments, the average particle size of the second quantum dot is 7–15 nm.

[0075] In some embodiments, the thickness of the optical functional layer 40 is 10-50 nm, for example, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc. Within this thickness range, the synergistic effect between the materials and thicknesses of the optical functional layer and other layers is beneficial for the optoelectronic device to have high luminous efficiency and long lifespan.

[0076] The first quantum dot and the second quantum dot can each be independently selected from, but not limited to, one or more of the following: single-structure quantum dots, core-shell structure quantum dots, and perovskite quantum dots.

[0077] The materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots are independently including, but are not limited to, one or more of the following: group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds may include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds may include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The group III-V compounds may include, but are not limited to, one or more of 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, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The group I-III-VI compounds may include, but are not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0078] As an example, the core-shell structured quantum dots may include, but are not limited to, one or more of CdSe / ZnS, CdZnSe / CdS, CdSe / CdS / ZnS, CdZnSe / ZnSe / ZnS, CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS.

[0079] It is understood that the shell of the core-shell structured quantum dot can be one or more layers.

[0080] The perovskite quantum dots can be, but are not limited to, doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors. The general structural formula of the inorganic perovskite semiconductor is AMX3, where A is Cs, M includes one or more of Pb, Sn, Cu, Ni, Cd, Cr, Mn, Co, Fe, Ge, Yb, and Eu, and X is a halogen, including one or more of Cl, Br, and I. The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BM'X'3, where B includes CH3(CH2). n-2 NH3 or [NH3(CH2)] n [NH3], where n≥2, M' includes one or more of Pb, Sn, Cu, Ni, Cd, Cr, Mn, Co, Fe, Ge, Yb, and Eu, and X' is a halogen, including one or more of Cl, Br, and I.

[0081] It is understood that the first quantum dot and the second quantum dot can each be independently one or more of red, green, and blue quantum dots. In at least one embodiment, the first quantum dot and the second quantum dot emit the same color light.

[0082] In some embodiments, the peak emission wavelength of the red quantum dot is 615–625 nm. In some embodiments, the peak emission wavelength of the green quantum dot is 535–555 nm. In some embodiments, the peak emission wavelength of the blue quantum dot is 465–480 nm.

[0083] It is understood that the first quantum dot and the second quantum dot may be the same or different. In at least one embodiment, the first quantum dot and the second quantum dot are the same.

[0084] In some embodiments, the surfaces of the first quantum dot and / or the second quantum dot may also be connected to ligands, which may be selected from, but are not limited to, fluorinated ligands. In some embodiments, the fluorinated ligands include, but are not limited to, one or more of trifluoroacetic acid, fluorinated mercaptoacetic acid, and fluorinated thiols. The fluorinated ligands can effectively reduce the surface energy of the quantum dots. During the preparation of the photofunctional layer 40 and the transition layer 30, the quantum dots with fluorinated ligands can migrate upwards, forming a stack with the photofunctional layer 40 as the upper layer and the transition layer 30 as the lower layer through phase separation.

[0085] Please see Figure 2 In some embodiments, the optoelectronic device 100 further includes a hole injection layer 60 located between the anode 10 and the hole functional layer 20.

[0086] Please see Figure 3 In some embodiments, the optoelectronic device 100 further includes an electron transport layer 70 located between the optical functional layer 40 and the cathode 50.

[0087] The anode 10 and the cathode 50 are electrodes known in the art for use in optoelectronic devices. For example, they can be, independently, but not limited to, doped metal oxide electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, elemental metal electrodes, or alloy electrodes. The material of the doped metal oxide electrode can be, but not limited to, one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), aluminum-doped magnesium oxide (AMO), and cadmium-doped zinc oxide. The composite electrode is an electrode formed by stacking two or more layers of conductive materials, such as AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc., where " / " indicates a stacked structure. For example, AZO / Ag / AZO represents a composite electrode comprising sequentially stacked AZO, Ag, and AZO layers. The material of the elemental metal electrode may include, but is not limited to, one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba. The alloy electrodes include, but are not limited to, Au:Mg alloy electrodes and Ag:Mg alloy electrodes.

[0088] In some embodiments, the anode 10 is an electrode with a relatively high work function, such as, but not limited to, a doped metal oxide electrode with a relatively high work function, a metal element electrode with a relatively high work function, and a carbon nanotube electrode. The metal element electrode with a high work function can be selected from, but is not limited to, Ni, Pt, Au, Ag, Ir, etc.

[0089] In some embodiments, the cathode 50 is an electrode with a relatively low work function, such as, but not limited to, a metallic elemental electrode, a composite electrode, and an alloy electrode with a relatively low work function. The metallic elemental electrode with a relatively low work function can be Ca, Ba, Al, Mg, etc. The composite electrode with a relatively low work function can be Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. The alloy electrode with a relatively low work function can be Au:Mg and Ag:Mg, etc.

[0090] The material of the hole injection layer 60 can be any material known in the art for hole injection layers, such as, but not limited to, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzphenanthrene (HAT-CN), PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s-MoO3 (PEDOT:PSS:s-MoO3), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), tetracyanoquinone dimethyl ether (F4-TCQN), copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide.

[0091] The material of the electron transport layer 70 can be any material known in the art for use in electron transport layers, for example, including but not limited to one or more of inorganic and organic electron transport materials. The inorganic electron transport material includes, but is not limited to, one or more of second-doped metal oxide particles, second-undoped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The material of the second undoped metal oxide particle includes, but is not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxide in the second doped metal oxide particle includes, but is not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping element in the second doped metal oxide particle includes, but is not limited to, one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The IIB-VIA group semiconductor material includes, but is not limited to, one or more of ZnS, ZnSe, and CdS. The IIIA-VA group semiconductor material includes, but is not limited to, one or more of InP and GaP. The IB-IIIA-VIA group semiconductor material includes, but is not limited to, one or more of CuInS and CuGaS. The organic electron transport materials include, but are not limited to, 8-hydroxyquinoline aluminum (Alq3), diphenyl[4-(triphenylsilyl)phenyl]oxyphosphine (TSPO1), 1,3,5-tris((3-pyridyl)-3-phenyl)benzene (TmPyPB), 2-(4-biphenyl)-5-phenyloxadiazole (PBD), bis(10-hydroxybenzo[h]quinoline)beryllium (Bebq2) (CAS: 148896-39-3), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), and 2,7-bis(diphenyloxyphosphine)-9,9'-spirobib[fluorene](S One or more of the following: PPO13), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)phenyl (TPBI), 4,6-bis(3,5-di(3-pyridylphenyl)-2-methylpyrimidine (B3PYMPM), 4,7-diphenyl-1,10-phenanthroline (BPhen), 2-(4'-tert-butylphenyl)-5-(4'-biphenyl)-1,3,4-oxadiazole, 2,9-dimethyl-4,7-diphenyl-1,10-o-diazaphenanthrene, 4,7-diphenyl-1,10-o-diazaphenanthrene, and bis(2-methyl-8-hydroxyquinoline-N1,O8)-1,1'-biphenyl-4-hydroxy)aluminum.

[0092] It is understood that the optoelectronic device 100 may also be provided with some functional layers that are conventionally used in optoelectronic devices and help to improve the performance of optoelectronic devices, such as electron blocking layer, hole blocking layer, electron injection layer, interface modification layer, etc.

[0093] It is understood that the materials of each layer of the optoelectronic device 100 can be adjusted according to the light emission requirements of the optoelectronic device 100.

[0094] In some embodiments, the optoelectronic device 100 further includes a substrate disposed on the side of the anode 10 away from the optical functional layer 40, or the substrate disposed on the side of the cathode 50 away from the optical functional layer 40.

[0095] The substrate can be a rigid substrate or a flexible substrate. In some embodiments, the substrate material may include, but is not limited to, one or more of glass, silicon wafer, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyethersulfone.

[0096] It is understood that the optoelectronic device 100 can be a quantum dot optoelectronic device (QLED) or an organic optoelectronic device (OLED).

[0097] Secondly, please refer to Figure 1 and Figure 4 This application also provides a method for fabricating a light-emitting device, comprising the following steps:

[0098] Step S11: Provide a photoelectric device preform, the photoelectric device preform including an anode 10;

[0099] Step S12: Provide a first P-type semiconductor material and place the first P-type semiconductor material on the anode 10 to obtain a hole functional layer 20;

[0100] Step S13: Provide a second P-type semiconductor material, quantum dots and solvent, mix them to obtain a mixed solution, place the mixed solution on the hole functional layer 20, heat treat it to obtain a transition layer 30 and an optical functional layer 40 sequentially stacked on the hole functional layer 20;

[0101] Step S14: A cathode 50 is disposed on the optical functional layer 40 to obtain an optoelectronic device 100.

[0102] The transition layer 30 includes a second P-type semiconductor material and a first quantum dot, and the optical functional layer 40 includes a second quantum dot. It is understood that the first quantum dot and the second quantum dot are the same.

[0103] In some embodiments, the hole functional layer 20 is a hole transport layer.

[0104] The preparation method involves placing a mixed solution comprising a second P-type semiconductor material, quantum dots, and a solvent on the hole functional layer 20. During the heat treatment process, due to the presence of fluorine-containing ligands on the surface of the quantum dots, the fluorine-containing ligands can effectively reduce the surface energy of the quantum dots. During the heat treatment process, the quantum dots with fluorine-containing ligands can migrate upwards, forming a layered structure through phase separation. The upper layer comprises a light functional layer 40 containing quantum dots, and the lower layer comprises a transition layer 30 containing quantum dots and the second P-type semiconductor material. This creates a buffering transition layer 30 between the hole functional layer 20 and the light functional layer 40.

[0105] Please see Figure 2 In some embodiments, the optoelectronic device preform includes a stacked anode 10 and a hole injection layer 60. Correspondingly, in step S12, the hole functional layer 20 is disposed on the hole injection layer 60.

[0106] Please see Figure 3 In some embodiments, the provision of a cathode 50 on the optical functional layer 40 includes: sequentially providing an electron transport layer 70 and a cathode 50 on the optical functional layer 40.

[0107] The anode 10, hole functional layer 20, transition layer 30, photofunctional layer 40, cathode 50, hole injection layer 60, and electron transport layer 70 are as described above and will not be repeated here.

[0108] The first P-type semiconductor material and the second P-type semiconductor material are as described above and will not be repeated here.

[0109] The quantum dot is one or more of the single-structure quantum dot, core-shell structure quantum dot, and perovskite quantum dot mentioned above.

[0110] The solvents include, but are not limited to, one or more of toluene, benzene, chlorobenzene, xylene, chloroform, acetone, n-octane, isooctane, cyclohexane, n-hexane, n-pentane, and isopentane.

[0111] It is understood that there is no limit to the amount of solvent added, as long as it can fully dissolve and disperse the second P-type semiconductor material and the quantum dots.

[0112] In some embodiments, the heat treatment temperature is 50–150°C, for example, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.; the heat treatment time is 5–30 min, for example, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc. Within the temperature and time range, the second P-type semiconductor material can be effectively cured, the solvent can be fully removed, and the damage to the quantum dots caused by excessively high temperatures can be avoided. This is beneficial for preparing a transition layer 30 with good leakage electron blocking ability and high hole transport ability, and for preparing an optical functional layer 40 with good conductivity and light emission performance.

[0113] The methods for depositing the first P-type semiconductor material on the anode 10, depositing the mixed solution on the hole functional layer 20, forming the hole injection layer 60, and forming the electron transport layer 70 can be implemented using conventional techniques in the art, such as chemical or physical methods. Chemical methods include chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, and co-precipitation. Physical methods include physical deposition and solution methods. Physical deposition methods include thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; solution methods include spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating, etc.

[0114] In at least one embodiment, the method of placing the mixed solution on the cavitation functional layer 20 can be the solution method described above.

[0115] It is understood that when the optoelectronic device 100 further includes functional layers that are conventionally used in optoelectronic devices to help improve the performance of the optoelectronic device, such as electron blocking layers, hole blocking layers, electron injection layers, interface modification layers, etc., the method of fabricating the optoelectronic device 100 may also include the step of fabricating the above-mentioned functional layers using conventional techniques in the art.

[0116] Thirdly, this application also relates to a display device, which includes the optoelectronic device 100.

[0117] The display device can be any electronic product with display function, including but not limited to smartphones, tablets, laptops, digital cameras, digital camcorders, smart wearable devices, smart weighing scales, in-vehicle displays, televisions, or e-book readers. Among them, smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0118] The present application will be specifically described below through specific embodiments. The following embodiments are only some embodiments of the present application and are not intended to limit the present application.

[0119] Example 1

[0120] The device structure in this embodiment is: ITO / TFB / quantum dot & PVK / quantum dot / Zn 0.9 Mg 0.1 O / Ag.

[0121] The method for fabricating the optoelectronic device in this embodiment is as follows:

[0122] A glass substrate with an ITO anode 10 having a thickness of 75nm is provided. The ITO conductive glass is cleaned with a cleaning agent to initially remove the stains on the surface. Then, it is ultrasonically cleaned in deionized water, isopropanol, acetone and deionized water for 20 minutes each to remove the impurities on the surface. Finally, it is dried with high-purity nitrogen and then irradiated with UV to improve the work function of the substrate.

[0123] Polyaniline material was spin-coated onto the ITO anode 10 and heated at 200°C for 30 min to obtain a hole injection layer 60 with a thickness of 30 nm.

[0124] TFB material was spin-coated onto the hole injection layer 60 and heated at 150°C for 10 min to obtain a hole functional layer 20 with a thickness of 25 nm.

[0125] CdZnSe / ZnSe / ZnS red quantum dots with an emission peak wavelength of 625nm, PVK, and toluene are provided and mixed to obtain a mixed solution. The mixed solution is spin-coated onto the hole functional layer 20 and heated at 100°C for 5 minutes to obtain a transition layer 30 with a thickness of 10nm and an optical functional layer 40 with a thickness of 20nm, which are sequentially stacked on the hole transport layer. The transition layer 30 includes a second P-type semiconductor material and a first quantum dot, and the optical functional layer 40 includes a second quantum dot. The content of the first quantum dot in the transition layer 30 is 5wt%.

[0126] Zn is spin-coated on the optical functional layer 40 0.9 Mg 0.1An ethanol solution of O was annealed at 100°C for 5 min to obtain an electron transport layer 70 with a thickness of 30 nm.

[0127] Ag is deposited on the electron transport layer 70 to obtain a cathode 50 with a thickness of 80 nm;

[0128] The optoelectronic device 100 was obtained by encapsulating it with epoxy resin in an environment where both oxygen and water content were below 0.1 ppm.

[0129] Example 2

[0130] This embodiment is basically the same as Embodiment 1, except that the content of the first quantum dot in the transition layer 30 is 1 wt% in this embodiment.

[0131] Example 3

[0132] This embodiment is basically the same as Embodiment 1, except that the content of the first quantum dot in the transition layer 30 is 10wt% in this embodiment.

[0133] Example 4

[0134] This embodiment is basically the same as Embodiment 1, except that the thickness of the transition layer 30 in this embodiment is 5nm.

[0135] Example 5

[0136] This embodiment is basically the same as Embodiment 1, except that the thickness of the transition layer 30 in this embodiment is 15nm.

[0137] Example 6

[0138] This embodiment is basically the same as Embodiment 1, except that the heating temperature after the mixed solution is spin-coated onto the cavity functional layer 20 is 50°C.

[0139] Example 7

[0140] This embodiment is basically the same as Embodiment 1, except that the heating temperature after the mixed solution is spin-coated onto the cavity functional layer 20 is 150°C.

[0141] Example 8

[0142] This embodiment is basically the same as that of Embodiment 1, except that in this embodiment, fluorene-aniline copolymer is used instead of TFB in Embodiment 1.

[0143] Example 9

[0144] This embodiment is basically the same as Embodiment 1, except that polyfluorene is used to replace PVK in Embodiment 1.

[0145] Example 10

[0146] This embodiment is basically the same as that of Embodiment 1, except that in this embodiment, polyaniline is used to replace TFB in Embodiment 1, and polyfluorene is used to replace PVK in Embodiment 1.

[0147] Example 11

[0148] This embodiment is basically the same as Embodiment 1, except that in this embodiment, CdZnSe / ZnSe / ZnS green quantum dots with an emission peak wavelength of 540nm are used to replace the CdZnSe / ZnSe / ZnS red quantum dots in Embodiment 1.

[0149] Example 12

[0150] This embodiment is basically the same as Embodiment 1, except that in this embodiment, CdZnSe / ZnSe / ZnS blue quantum dots with an emission peak wavelength of 475nm are used to replace the CdZnSe / ZnSe / ZnS red quantum dots in Embodiment 1.

[0151] Comparative Example 1

[0152] This comparative example is basically the same as Example 1, except that it does not include the transition layer in Example 1. That is, the device structure of this comparative example is ITO / TFB / quantum dot / Zn. 0.9 Mg 0.1 O / Ag.

[0153] The fabrication method of the optoelectronic device in this comparative example is as follows:

[0154] A glass substrate with an ITO anode 10 having a thickness of 75nm is provided. The ITO conductive glass is cleaned with a cleaning agent to initially remove the stains on the surface. Then, it is ultrasonically cleaned in deionized water, isopropanol, acetone and deionized water for 20 minutes each to remove the impurities on the surface. Finally, it is dried with high-purity nitrogen and then irradiated with UV to improve the work function of the substrate.

[0155] Polyaniline material was spin-coated onto the ITO anode 10 and heated at 200°C for 30 min to obtain a hole injection layer 60 with a thickness of 30 nm.

[0156] TFB material was spin-coated onto the hole injection layer 60 and heated at 150°C for 10 min to obtain a hole functional layer 20 with a thickness of 25 nm.

[0157] CdZnSe / ZnSe / ZnS red quantum dots with an emission peak wavelength of 625nm and toluene are provided, mixed to obtain a mixed solution, and the mixed solution is spin-coated onto the hole functional layer 20 and heated at 100°C for 5 minutes to obtain a light functional layer 40 with a thickness of 20nm.

[0158] Zn is spin-coated on the optical functional layer 40 0.9 Mg 0.1 An ethanol solution of O was annealed at 100°C for 5 min to obtain an electron transport layer 70 with a thickness of 30 nm.

[0159] Ag is deposited on the electron transport layer 70 to obtain a cathode 50 with a thickness of 80 nm;

[0160] The optoelectronic device 100 was obtained by encapsulating it with epoxy resin in an environment where both oxygen and water content were below 0.1 ppm.

[0161] Comparative Examples 2-3

[0162] Comparative Examples 2 and 3 are basically the same as Comparative Example 1, except that Comparative Examples 2 and 3 use CdZnSe / ZnSe / ZnS green quantum dots with an emission peak wavelength of 540nm and CdZnSe / ZnSe / ZnS blue quantum dots with an emission peak wavelength of 475nm, respectively, to replace the CdZnSe / ZnSe / ZnS red quantum dots in Comparative Example 1.

[0163] The current efficiency of the optoelectronic devices in Examples 1-12 and Comparative Examples 1-3 was tested at lifetimes of T95@1000nit and 1000nits. The test results are shown in Table 1.

[0164] The lifetime test method T95@1000nit is as follows: In CDA gas, under constant current drive, the time it takes for the device brightness to decay to a certain percentage of its maximum brightness is measured. The time for the brightness to decay to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. To shorten the lifetime testing cycle, device lifetime testing is usually performed at high brightness by accelerating device aging, and the lifetime at low brightness is obtained by fitting the decay fitting formula. For example, the lifetime at 1000 nits is denoted as T95@1000nits, and the calculation formula is as follows:

[0165]

[0166] Among them, T95 L The lifespan at low brightness is typically taken as the lifespan at 1000 nits, T95. H The lifetime at high brightness, i.e., the measured lifetime, L H L is the maximum brightness that the device accelerates to. L The typical value is 1000 nits, where A is the acceleration factor, taken as 1.7. The constant current is 2 mA.

[0167] All the above tests were conducted at room temperature with an air humidity of 30-60%.

[0168] The current efficiency at 1000 nits was measured using a Fostar FPD optical characteristic measurement device. An efficiency testing system was built by controlling a QEPRO spectrometer, Keithley 2400, and Keithley 6485 via LabVIEW to measure parameters such as voltage, current, brightness, and emission spectrum, and the current efficiency was calculated.

[0169] Table 1:

[0170] T95@1000 nit (h) Current efficiency (cd / A) at 1000 nits Example 1 2200 23 Example 2 2000 22 Example 3 2100 21 Example 4 1900 22 Example 5 2100 21 Example 6 2100 23 Example 7 2200 23 Example 8 2500 25 Example 9 1900 22 Example 10 2000 22 Example 11 4200 72 Example 12 75 8 Comparative Example 1 1800 21 Comparative Example 2 3500 70 Comparative Example 3 60 8

[0171] As shown in Table 1:

[0172] Compared to the red light optoelectronic device of Comparative Example 1, the optoelectronic devices of Examples 1-11 have a longer lifetime and higher current efficiency. It can be seen that setting the transition layer described in this application between the hole transport layer and the optical functional layer can effectively improve the lifetime and current efficiency of the optoelectronic device. The reason may be that the transition layer described in this application serves as a buffer interface between the hole transport layer and the optical functional layer. In this way, the leakage electrons that jump over the optical functional layer first enter the transition layer and recombine with the holes in the transition layer to form excitons. Then, they are transferred to the quantum dot optical functional layer through energy resonance transfer. This can effectively reduce the damage of leakage electrons to the first P-type semiconductor material in the hole transport layer.

[0173] Compared to the green optoelectronic device of Comparative Example 2, the green optoelectronic device of Example 11 has a longer lifetime and higher current efficiency. It can be seen that setting the transition layer described in this application between the hole transport layer and the optical functional layer can effectively improve the lifetime and current efficiency of the optoelectronic device. The reason may be that the transition layer described in this application serves as a buffer interface between the hole transport layer and the optical functional layer. In this way, the leakage electrons that jump over the optical functional layer first enter the transition layer and recombine with the holes in the transition layer to form excitons. Then, they are transferred to the quantum dot optical functional layer through energy resonance transfer. This can effectively reduce the damage of leakage electrons to the first P-type semiconductor material in the hole transport layer.

[0174] Compared to the blue light optoelectronic device of Comparative Example 3, the blue light optoelectronic device of Example 12 has a longer lifespan. It can be seen that setting the transition layer described in this application between the hole transport layer and the optical functional layer can effectively improve the lifespan of the blue light optoelectronic device. The reason may be that the transition layer described in this application serves as a buffer interface between the hole transport layer and the optical functional layer. In this way, the leakage electrons that jump over the optical functional layer first enter the transition layer and recombine with the holes in the transition layer to form excitons, and then transfer to the quantum dot optical functional layer through energy resonance transfer. This can effectively reduce the damage of leakage electrons to the first P-type semiconductor material in the hole transport layer.

[0175] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An optoelectronic device, characterized in that, It includes an anode, a hole-functional layer, a transition layer, a photofunctional layer, and a cathode stacked in sequence, wherein the hole-functional layer includes a first P-type semiconductor material, and the transition layer includes a second P-type semiconductor material and a first quantum dot.

2. The optoelectronic device as described in claim 1, characterized in that, The hole functional layer is a hole transport layer; and / or The optical functional layer includes a second quantum dot.

3. The optoelectronic device as described in claim 1, characterized in that, The LUMO energy level of the second P-type semiconductor material is greater than or equal to the LUMO energy level of the first P-type semiconductor material; and / or The absolute value of the HOMO energy level of the first P-type semiconductor material is greater than or equal to 2.5 eV; and / or The HOMO energy level of the first p-type semiconductor material is -4.8 to -5.5 eV; and / or The HOMO energy level range of the second P-type semiconductor material is the same as that of the first P-type semiconductor material up to -6.0 eV.

4. The optoelectronic device as described in claim 2, characterized in that, The total thickness of the hole functional layer and the transition layer is 10–50 nm; and / or The thickness of the transition layer is 5–15 nm; and / or The thickness of the optical functional layer is 10–50 nm; and / or In the transition layer, the content of the first quantum dot is 1–10 wt%; and / or The average particle size of the first quantum dot is 2–15 nm; and / or The average particle size of the second quantum dot is 7–15 nm; and / or The surface of the first quantum dot is attached with a ligand selected from fluorinated ligands, including one or more of trifluoroacetic acid, fluorinated thioglycolic acid, and fluorinated thiols; and / or The surface of the second quantum dot is attached with a ligand, which is selected from fluorinated ligands, including one or more of trifluoroacetic acid, fluorinated mercaptoacetic acid, and fluorinated thiols.

5. The optoelectronic device as described in claim 1, characterized in that, The first P-type semiconductor material includes one or more of a first P-type organic semiconductor material and a first P-type inorganic semiconductor material, and the second P-type semiconductor material includes one or more of a second P-type organic semiconductor material and a second P-type inorganic semiconductor material.

6. The optoelectronic device as described in claim 5, characterized in that, The first and second P-type organic semiconductor materials include poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(N,N'bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, poly(phenylenevinylene), and poly[2-methoxy-5-(2-ethylhexoxy)-1,4- [Phenylidene vinylidene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylidene], polyaniline, polythiophene, polypyrrole, fluorene-aniline copolymer, polyfluorene, poly(p-)phenylenevinylidene, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, PEDOT, PEDOT:PSS, PEDOT:PSS derivatives doped with s-MoO3, or one or more of these; and / or The first P-type inorganic semiconductor material and the second P-type inorganic semiconductor material comprise one or more of the following: first doped metal oxide particles, first undoped metal oxide particles, metal sulfides, and metal nitrides. The metal oxides in the first doped metal oxide particles and the first undoped metal oxide particles each independently comprise one or more of the following: MoO3, WO3, NiO, CrO3, CuO, Cu2O, and V2O5. The doping element in the first doped metal oxide particles comprises one or more of the following: Mo, W, Ni, Cr, Cu, and V. The metal sulfide comprises one or more of the following: CuS, MoS3, and WS3. The metal nitride comprises P-type gallium nitride; and / or The first P-type semiconductor material may be the same as or different from the second P-type semiconductor material.

7. The optoelectronic device as described in claim 2, characterized in that, The first quantum dot and the second quantum dot are each independently selected from one or more of the following: single-structure quantum dots, core-shell quantum dots, and perovskite quantum dots. The core-shell quantum dots have one or more shells. The materials of the single-structure quantum dots, the core materials of the core-shell quantum dots, and the shell materials of the core-shell quantum dots each independently include one or more of the following: group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, and ZnS. The compounds are one or more of the following: SnS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe, wherein the group IV-VI compounds include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, and PbSe. Te, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, and the III-V compound includes one or more of 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, and G. The perovskite quantum dots are one or more of the following: aAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The group I-III-VI compounds include one or more of CuInS2, CuInSe2, and AgInS2. The perovskite quantum dots include doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors. The inorganic perovskite semiconductor has the general structural formula AMX3, where A is cesium, M includes one or more of lead, tin, copper, nickel, cadmium, manganese, cobalt, iron, chromium, ytterbium, and europium, and X is a halogen.The organic-inorganic hybrid perovskite semiconductor comprises one or more of chlorine, bromine, and iodine, and has the general structural formula BM'X'3, wherein B includes CH3(CH2). n-2 NH3 or [NH3(CH2)] n [NH3], where n≥2, M' includes one or more of lead, tin, copper, nickel, cadmium, manganese, cobalt, iron, chromium, ytterbium, and europium, and X' is a halogen, including one or more of chlorine, bromine, and iodine; and / or The first quantum dot may be the same as or different from the second quantum dot.

8. The optoelectronic device as described in claim 2, characterized in that, The anode and the cathode each independently comprise a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal element electrode, or an alloy electrode. The doped metal oxide particle electrode is made of one or more of the following materials: indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, and aluminum-doped magnesium oxide. The composite electrode comprises one or more of the following: AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, or ZnS / Al / ZnS. The metal element electrode is made of one or more of the following: Ag, Al, Cu, Mo, Au, Pt, Ca, Mg, and Ba; and / or The optoelectronic device further includes a hole injection layer located between the anode and the hole transport layer. The hole injection layer is made of one or more of the following materials: 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, PEDOT, PEDOT:PSS, PEDOT:PSS-doped s-MoO3 derivatives, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinone dimethylamine, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide; and / or The optoelectronic device further includes an electron transport layer located between the optical functional layer and the cathode. The electron transport layer is made of one or more inorganic and organic electron transport materials. The inorganic electron transport material includes one or more of a second-doped metal oxide particle, a second-undoped metal oxide particle, a group IIB-VIA semiconductor material, a group IIIA-VA semiconductor material, and a group IB-IIIA-VIA semiconductor material. The second-undoped metal oxide particle is made of one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxide in the second-doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping element in the second-doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The group IIB-VIA semiconductor material includes one or more of ZnS, ZnSe, and CdS. The group IIIA-VA semiconductor material includes InP and GaP. One or more of the following, wherein the IB-IIIA-VIA group semiconductor materials include one or more of CuInS and CuGaS; the organic electron transport materials include 8-hydroxyquinoline aluminum, diphenyl[4-(triphenylsilyl)phenyl]phosphine, 1,3,5-tris((3-pyridyl)-3-phenyl)benzene, 2-(4-biphenyl)-5-phenyloxadiazole, bis(10-hydroxybenzo[h]quinoline)beryllium, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, and 2,7-bis(diphenylphosphine)-9,9 One or more of the following: '-spirobis[fluorene], 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 4,6-bis(3,5-di(3-pyridinylphenyl)-2-methylpyrimidine, 4,7-diphenyl-1,10-phenanthroline, 2-(4'-tert-butylphenyl)-5-(4'-biphenyl)-1,3,4-oxadiazole, 2,9-dimethyl-4,7-diphenyl-1,10-o-diazaphenanthroline, 4,7-diphenyl-1,10-o-diazaphenanthroline, and bis(2-methyl-8-hydroxyquinoline-N1,O8)-1,1'-biphenyl-4-hydroxy)aluminum.

9. A method for fabricating an optoelectronic device, characterized in that, Includes the following steps: Provide a photoelectric device preform, the photoelectric device preform including an anode; A first P-type semiconductor material is provided, and the first P-type semiconductor material is disposed on the anode to obtain a hole functional layer; A second P-type semiconductor material, quantum dots, and a solvent are provided and mixed to obtain a mixed solution. The mixed solution is then placed on the hole functional layer and subjected to heat treatment to obtain a transition layer and an optical functional layer sequentially stacked on the hole functional layer. The transition layer includes a second P-type semiconductor material and a first quantum dot, and the optical functional layer includes a second quantum dot. A cathode is placed on the optical functional layer to obtain an optoelectronic device.

10. The preparation method according to claim 9, characterized in that, The hole functional layer is a hole transport layer; and / or The heat treatment temperature is 50–150°C; and / or The heat treatment time is 5 to 30 minutes; and / or The quantum dots are surface-attached with ligands selected from fluorinated ligands, including one or more of trifluoroacetic acid, fluorinated thioglycolic acid, and fluorinated thiols; and / or The solvent includes one or more of toluene, benzene, chlorobenzene, xylene, chloroform, acetone, n-octane, isooctane, cyclohexane, n-hexane, n-pentane, and isopentane.

11. A display device, characterized in that, It includes the optoelectronic device according to any one of claims 1 to 8, or the optoelectronic device prepared by the preparation method according to any one of claims 9 to 10.

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