Optoelectronic device, method of manufacturing the same, and display device

Abstract

This application discloses an optoelectronic device, its fabrication method, and a display device. The optoelectronic device includes a stacked anode, a light-emitting layer, a first electron transport layer, and a cathode. The first electron transport layer includes a first film layer and a second film layer stacked sequentially from the anode to the cathode. The material of the first film layer includes a first metal oxide, and the material of the second film layer includes a metal nitride. The optoelectronic device proposed in this application, by disposing a stable metal nitride on the side of the first electron transport layer near the cathode, can increase interface stability, prevent ion migration, suppress metal electrode electromigration, and contribute to improving the stability of the device.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to an optoelectronic device, its fabrication method, and a display apparatus. Background Technology

[0002] Optoelectronic devices emit light by releasing energy through the recombination of electrons and holes, converting electrical signals into optical signals, and are widely used in the lighting field. Optoelectronic devices typically have an anode, a cathode, and an electron transport layer located between the anode and the cathode.

[0003] Under the influence of high current and temperature, electrons in the metal electrode are prone to collision with metal atoms in the electron transport layer, causing metal atoms to migrate along the direction of electron flow, resulting in metal electromigration and affecting the stability of the device. Summary of the Invention

[0004] In view of this, this application provides an optoelectronic device, a method for fabricating the same, and a display device.

[0005] The embodiments of this application are implemented as follows:

[0006] In a first aspect, embodiments of this application provide an optoelectronic device, including a stacked anode, a light-emitting layer, a first electron transport layer, and a cathode. The first electron transport layer includes a first film layer and a second film layer stacked sequentially along the anode to the cathode. The material of the first film layer includes a first metal oxide, and the material of the second film layer includes a metal nitride.

[0007] Secondly, embodiments of this application provide a method for fabricating an optoelectronic device, comprising the following steps:

[0008] It provides a stacked anode and light-emitting layer;

[0009] A first electron transport layer is prepared on the side of the light-emitting layer opposite to the anode;

[0010] A cathode is disposed on the side of the first electron transport layer opposite to the light-emitting layer;

[0011] The fabrication of the first electron transport layer includes depositing a first metal oxide and a metal nitride on the side of the light-emitting layer away from the anode to obtain a stacked first film and a second film. The first film is disposed close to the light-emitting layer, and the material of the first film includes the first metal oxide, while the material of the second film includes the metal nitride.

[0012] Thirdly, embodiments of this application provide a display device, including the optoelectronic device described above, or the optoelectronic device prepared by the preparation method described above.

[0013] The optoelectronic device proposed in this application has a stable metal nitride disposed on the side of the first electron transport layer near the cathode, which can increase interface stability, prevent ion migration, suppress metal electrode electromigration, and help improve the stability of the device. Attached Figure Description

[0014] 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.

[0015] Figure 1 This is a schematic diagram of the structure of an optoelectronic device provided in an embodiment of this application;

[0016] Figure 2 This is a schematic diagram of the structure of an optoelectronic device provided in another embodiment of this application;

[0017] Reference numerals: Optoelectronic device 100; Anode 10; Cathode 20; Light-emitting layer 30; Hole transport layer 40; Hole injection layer 50; First electron transport layer 60; First metal oxide 61; Metal nitride 62; Metal nitride 63; Second electron transport layer 70. Detailed Implementation

[0018] The technical solutions in 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 in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, 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. In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. In addition, in the description of this application, the term "including" means "including but not limited to". 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 only for convenience and conciseness 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 values ​​within that range. For example, it should be assumed that the description of a range from 1 to 6 specifically discloses subranges 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., as well as 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 range referred to.

[0019] 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.

[0020] 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.

[0021] This application provides an optoelectronic device 100, which may be a quantum dot light-emitting device (QLED), an organic light-emitting device (OLED), etc. Figure 1As shown, the optoelectronic device 100 includes a stacked anode 10, a light-emitting layer 30, a first electron transport layer 60, and a cathode 20. Based on the distribution of materials in the film layers, the first electron transport layer 60 may include a first film layer and a second film layer sequentially stacked along the anode 10 to the cathode 20. The material of the first film layer includes a first metal oxide 61, and the material of the second film layer includes a metal nitride 63.

[0022] Metal nitride 63 refers to MN, where M is a metallic element. It's understandable that MN only indicates the composition of M and N (nitrogen) elements; if it represents the content of each element, it would correspond to M3N. a Where 'a' represents the valence of M, for example, when M is Zn, metal nitride 63 is Zn3N2. It should be noted that when M is composed of multiple metal elements, 'a' is the average valence calculated based on the respective proportions of each element. For example, when M is Zn and Mg, and their molar ratio is 3:1, 'a' is (3×2+2×1) / 4, which is 2. The metal nitride 63 exhibits good stability, and its work function is close to that of commonly used cathode 20 materials such as Ag and Al.

[0023] The optoelectronic device 100 proposed in this application has a stable metal nitride 63 disposed on the side of the first electron transport layer 60 near the cathode 20. This increases interface stability, prevents ion migration, suppresses electromigration of the metal electrode, and helps improve device stability. Simultaneously, since the work function of the metal nitride 63 is close to that of commonly used cathode 20 materials, in optoelectronic devices 100 based on these cathode 20 materials, the metal nitride 63 distributed on the side of the first electron transport layer 60 facing the cathode 20 can form a transition interface between the first metal oxide 61 and the cathode 20. This reduces the potential barrier and decreases interface carrier accumulation, thereby helping to improve the luminescent performance (e.g., external quantum efficiency EQE, brightness, etc.) of the optoelectronic device 100 and extend its lifetime.

[0024] The first metal oxide 61 can be a metal oxide commonly used in electron transport layers in the art, possessing electron transport properties. For example, it can be one or more of undoped oxides and doped oxides. Specifically, the undoped oxide can include, but is not limited to, one or more of ZnO, SnO2, and TiO2; the doped oxide includes oxides doped with dopant elements, wherein the oxide includes one or more of ZnO, SnO2, and TiO2, and the dopant element includes one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu. By incorporating dopant elements, the electron transport properties of the oxide can be modulated, making it more compatible with other films in the optoelectronic device 100. Furthermore, when the metal oxide is a doped metal oxide, the molar percentage of the dopant element in the doped metal oxide is greater than 0 and less than or equal to 20%; for example, it can be a value greater than 0 and less than 0.001%, 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 5%, 8%, 10%, 15%, 17%, 20%, or any two of the above values. By controlling it within this range, the electron transport properties of the doped metal oxide can be precisely controlled.

[0025] In some embodiments, in the first electron transport layer 60, the metal element contained in the first metal oxide 61 is the same as the metal element contained in the metal nitride 63; for example, when the first metal oxide 61 is zinc oxide (ZnO), the metal nitride 63 is zinc nitride (Zn3N2). It is understood that when the first metal oxide 61 is a doped metal oxide, the metal element in the metal nitride 63 also includes the dopant element found in the doped metal oxide. Specifically, taking the first metal oxide 61 listed above as an example, the nitride includes one or more of undoped nitride and doped nitride; the undoped oxide includes one or more of Zn3N2, Sn3N4, and Ti3N2; the doped nitride includes nitride doped with doping elements, the nitride includes one or more of Zn3N2, Sn3N4, and Ti3N2, and the doping element includes one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu, such as ZnAlN, ZnMgN, etc. It is understood that ZnAlN, ZnMgN, etc. only indicate that they are composed of Zn, Al (or Mg) and N elements, and do not involve the content of each element. In practical applications, the doping amount can be adjusted and the proportion of each element can be allocated as needed. This application does not impose any restrictions on this. By designing the metal elements contained in the first metal oxide 61 and the metal nitride 63 to be of the same type, the energy level of the metal nitride 63 can be better matched with the cathode 20 and the first metal oxide 61, forming a better transition interface. On the other hand, when the metal elements are the same, in actual fabrication, a metal oxide layer can be first deposited using the first metal oxide 61, and then the material of this film layer can be directly used as a metal source to deposit the metal nitride 63. This not only simplifies the operation but also increases the concentration of metal cation defects at the interface, which helps to further reduce the tunneling barrier at the interface and improve the device's luminescence performance and lifetime.

[0026] The thickness of the first electron transport layer 60 is 5–40 nm; for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, or any two of the above values. Controlling the thickness within this range helps to promote carrier transport and suppress ion migration.

[0027] In some embodiments, the material of the second film layer further includes metal nitride 62, wherein the metal nitride 62 contains the same metal element as the first metal oxide 61. This serves as a transition between the first metal oxide 61 and the metal nitride 63. The metal nitride 62 refers to MNO, where M is a metal element. As mentioned above, MNO only indicates that it is composed of M, N, and O elements; if it represents the content of each element, it corresponds to M. x N y O z ax = 3y + 2z, ​​where x, y, and z are all positive numbers, and a is the valence of M.

[0028] Furthermore, in some embodiments, the metal nitride 62 is distributed on the side of the second film layer facing the first film layer; in other embodiments, the metal nitride 63 is distributed on the side of the second film layer facing the cathode 20. Specifically, in the first electron transport layer 60, the first metal oxide 61, the metal nitride 62, and the metal nitride 63 are distributed sequentially along the direction from the anode 10 to the cathode 20.

[0029] In some embodiments, the nitrogen content in the first electron transport layer 60 gradually increases in the direction from the anode 10 to the cathode 20; in other embodiments, the oxygen content in the first electron transport layer 60 gradually decreases in the direction from the anode 10 to the cathode 20. The distribution of nitrogen closer to the cathode 20 helps to better suppress ion migration and reduce the accumulation of interfacial carriers.

[0030] In some embodiments, the molar ratio of metal element, nitrogen element and oxygen element in the first electron transport layer 60 is 1:(0.1~0.3):(0.7~0.9); for example, it can be 1:0.1:(0.7~0.9), 1:0.15:(0.7~0.9), 1:0.2:(0.7~0.9), 1:0.25:(0.7~0.9), 1:0.3:(0.7~0.9), 1:(0.1~0.3):0.7, 1:(0.1~0.3):0.75, 1:(0.1~0.3):0.8, 1:(0.1~0.3):0.85, 1:(0.1~0.3):0.9, etc. By controlling the element ratio within this range, the proportion of metal oxides and metal nitrides 63 in the first electron transport layer 60 can be well controlled. This not only improves the suppression of ion migration, the improvement of interfacial carrier accumulation, and the stability, but also ensures carrier transport in the device, further improving the device's luminescence performance and lifetime.

[0031] In the optoelectronic device 100, there may be a problem where electron injection exceeds hole injection, which can easily cause an imbalance in electron-hole injection within the device, making it easy for charge to accumulate between the light-emitting layer 30 and the first electron transport layer 60. Therefore, in some embodiments, the optoelectronic device 100 further includes a second electron transport layer 70. (See also...) Figure 2 The second electron transport layer 70 is disposed between the first electron transport layer 60 and the light-emitting layer 30, and the material of the second electron transport layer 70 includes a second metal oxide. An interface barrier can be established between the second electron transport layer 70 and the first electron transport layer 60, which effectively blocks excess electrons from reaching the surface of the light-emitting layer 30, improves the electron injection-hole injection balance of the device, reduces exciton quenching and efficiency roll-off caused by the charge on the light-emitting layer 30, and improves the light-emitting performance and lifetime of the device.

[0032] The second metal oxide may include one or more of undoped oxides and doped oxides; the undoped oxide may include, but is not limited to, one or more of ZnO, SnO2, and TiO2; the doped oxide may include, but is not limited to, oxides doped with a dopant element, wherein the oxide includes one or more of ZnO, SnO2, and TiO2, and the dopant element may include, but is not limited to, one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu. In some embodiments, the molar percentage of the dopant element in the doped metal oxide is greater than 0 and less than or equal to 20%. For example, it may be a value greater than 0 and less than 0.001%, 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 5%, 8%, 10%, 15%, 17%, 20%, and any range between any two of the above values.

[0033] The metal element contained in the second metal oxide may be the same as or different from the metal element contained in the first electron transport layer 60. In some embodiments, the second metal oxide may be a doped oxide, and the doping element may be selected from one or more of Al, Mg, Li, and Sn, which helps to slow down electron injection and better control the balance between electron injection and hole injection in the device.

[0034] In some embodiments, the thickness of each second electron transport layer 70 is 15 to 30 nm; for example, it can be 15 nm, 18 nm, 20 nm, 25 nm, 27 nm, 30 nm, or any two of the above values, which helps to better control the balance between electron injection and hole injection in the device.

[0035] The second electron transport layer 70 can be provided in one or more forms. When multiple second electron transport layers 70 are provided, the materials of the multiple second electron transport layers 70 can be the same or different. Furthermore, the material of the second electron transport layer 70 can be the same as or different from the material of the first electron transport layer 60. In some embodiments, the optoelectronic device 100 includes one or two layers of the second electron transport layer 70; this allows for better control of the balance between electron injection and hole injection in the device, improving the charging of the light-emitting layer 30 and enhancing its luminous performance.

[0036] In some embodiments, the total thickness of the first electron transport layer 60 and the second electron transport layer 70 is 25 to 40 nm; for example, 25 nm, 27 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, and any two of the above values. Regardless of how many layers of the second electron transport layer 70 are provided, controlling the total thickness of the first electron transport layer 60 and the second electron transport layer 70 within this range helps to better regulate the balance of electron injection and hole injection in the device and improve carrier transport.

[0037] The material of the light-emitting layer 30 may include organic light-emitting materials or quantum dots.

[0038] The organic light-emitting material is a material known in the art for use in the organic light-emitting layer 30. For example, the material may be selected from, but is not limited to, the light-emitting layer 30, including organic light-emitting materials or quantum dots. The organic light-emitting material includes at least one of diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, TBPe fluorescent material emitting blue light, TTPA fluorescent material emitting green light, TBRb fluorescent material emitting orange light, and DBP fluorescent material emitting red light.

[0039] The quantum dot is a quantum dot known in the art for use in the quantum dot emitting layer 30, such as one of red quantum dots, green quantum dots, and blue quantum dots. The quantum dot may be selected from, but is not limited to, at least one of single-structure quantum dots, core-shell quantum dots, and perovskite semiconductor materials. The shell of the core-shell quantum dot comprises one or more layers. 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 respectively include 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 include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, and CdSTe. At least one of the following: 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 include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, S At least one of nSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V compound includes at least one 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, and GaAlNP. At least one of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds include at least one of CuInS2, CuInSe2, and AgInS2; the perovskite semiconductor material includes 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. +Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of them.

[0040] As an example, the quantum dots of the core-shell structure may be selected from, but not limited to, at least one of CdZnSe / CdZnSe / ZnSe / CdZnS / ZnS, CdZnSe / CdZnSe / CdZnS / ZnS CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS and InP / ZnSe / ZnS. It should be noted that for the materials of the aforementioned single-structure quantum dots, or the core materials of the core-shell structure quantum dots, or the shell materials of the core-shell structure quantum dots, the chemical formulas provided only indicate the elemental composition and do not indicate the content of each element. For example, CdZnSe only represents that it is composed of three elements, Cd, Zn, and Se. If the content of each element is to be represented, it corresponds to Cd x Zn 1-x Se, where 0 < x < 1. It can be understood that the core material of the core-shell structure quantum dots and the materials of each shell layer are expressed by connecting with " / ", and the order from left to right is the types of materials of the quantum dots from the inside to the outside: core material / first shell layer material / Nth shell layer material, where N is an integer greater than or equal to 1. For example, CdSe / CdZnSeS / ZnS represents a core-shell structure quantum dot with two shell layers, whose core material is CdSe, the material of the first shell layer coated on the core is CdZnSeS, and the material of the second shell layer coated outside the first shell layer is ZnS.

[0041] The thickness of the light-emitting layer 30 may be 20 nm to 60 nm; for example, it may be 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, and the range between any two of the above values.

[0042] The anode 10 and the cathode 20 each independently include a doped metal oxide particle electrode, a metal and metal oxide composite electrode, a graphene electrode, a carbon nanotube electrode, or a metal electrode. The material of the doped metal oxide particle electrode is selected from 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 metal and metal oxide composite electrode is selected from 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, and ZnS / Al / ZnS. The material of the metal electrode is selected from one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg, and Ba. Wherein, " / " indicates a stacked structure. For example, the composite electrode AZO / Ag / AZO represents an electrode with a three-layer stacked structure consisting of an AZO layer, an Ag layer, and an AZO layer. The thickness of the anode 10 can be 50–120 nm, and the thickness of the cathode 20 can be 10–100 nm.

[0043] In some embodiments, the optoelectronic device 100 may further include a hole functional layer located between the light-emitting layer 30 and the anode 10. The hole functional layer includes one or both of a hole injection layer 50 and a hole transport layer 40. When the hole functional layer includes both a hole injection layer 50 and a hole transport layer 40, the hole injection layer 50 is located between the hole transport layer 40 and the anode 10. In one embodiment, the optoelectronic device 100 may include, from bottom to top, an anode 10, a hole injection layer 50, a hole transport layer 40, a light-emitting layer 30, an electron transport layer, and a cathode 20, stacked sequentially. In another embodiment, the optoelectronic device 100 may include, from bottom to top, a cathode 20, an electron transport layer, a light-emitting layer 30, a hole transport layer 40, a hole injection layer 50, and an anode 10, stacked sequentially.

[0044] The material of the hole transport layer 40 can be selected from organic materials with hole transport capabilities, including but not limited to 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), and N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine (α-NP). D), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro(spiro-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4”-tris(N-3-methylphenyl-N-phenylamino) The following are included in the list of poly(p-)phenylene oxide (m-MTDATA), poly(p-)phenylene vinylidene (PPV), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylidene] (MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylidene] (MOMO-PPV), 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS, poly(N-vinylcarbazole) (PVK), polymethacrylate, poly(9,9-octylfluorene), N,N'-di(naphthyl-1-yl)-N,N'-diphenylbenzidine (NPB), spiroNPB, doped graphene, undoped graphene, and one or more transition metal oxides, wherein the transition metal oxides include one or more of NiO, MoO2, WO3, and CuO. In some embodiments, the thickness of the hole transport layer 40 can be 20 to 60 nm, for example, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, or any value between any two of the above.

[0045] The hole injection layer 50 is made of materials known in the art that have hole injection capabilities, including but not limited to poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethylethane (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (HATCN), copper polyester carbonate (CuPc), transition metal oxides, and metal chalcogenides; wherein the transition metal oxides include one or more of NiO, MoO2, WO3, and CuO; and the metal chalcogenides include one or more of MoS2, MoSe2, WS3, WSe3, and CuS. In some embodiments, the thickness of the hole injection layer 50 can be 20 to 60 nm, for example, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, or any value between any two of the above.

[0046] It is understood that the optoelectronic device 100 may also be provided with some functional layers that are conventionally used in optoelectronic devices 100 and help to improve device performance, such as electron blocking layer, hole blocking layer, interface modification layer, etc.

[0047] It is understood that the materials of each layer of the optoelectronic device 100 can be adjusted according to the optoelectronic requirements of the optoelectronic device 100.

[0048] This application also discloses a method for fabricating an optoelectronic device 100. Using this method, the aforementioned optoelectronic device 100 can be fabricated. The fabrication method includes the following steps:

[0049] S10 provides a stacked anode 10 and a light-emitting layer 30.

[0050] S20, a first electron transport layer 60 is formed on the side of the light-emitting layer 30 opposite to the anode 10;

[0051] The fabrication of the first electron transport layer 60 includes depositing a first metal oxide 61 and a metal nitride 63 on the side of the light-emitting layer 30 away from the anode 10 to obtain a stacked first film and a second film. The first film is disposed close to the light-emitting layer 30, and the material of the first film includes the first metal oxide 61, while the material of the second film includes the metal nitride 63.

[0052] S30, a cathode 20 is disposed on the side of the first electron transport layer 60 away from the light-emitting layer 30.

[0053] The first metal oxide 61 may include one or more of undoped oxides and doped oxides. The undoped oxide may include, but is not limited to, one or more of ZnO, SnO2, and TiO2; the doped oxide includes oxides doped with a dopant element, which may include, but is not limited to, one or more of ZnO, SnO2, and TiO2, and the dopant element may include, but is not limited to, one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu. When the first metal oxide 61 is selected from doped metal oxides, the molar percentage of the dopant element in the doped metal oxide is greater than 0 and less than or equal to 20%.

[0054] In step S20, where a first metal oxide 61 and a metal nitride 63 are deposited on the side of the light-emitting layer 30 away from the anode 10 to obtain a stacked first and second film layer, various methods can be used to prepare the first and second film layers. For example, the first metal oxide 61 can be deposited first on the side of the light-emitting layer 30 away from the anode 10 to form the first film layer; then, the metal nitride 63 can be deposited on the side of the first film layer away from the light-emitting layer 30 to obtain the second film layer.

[0055] For example, it can be implemented by the following steps: providing a first metal oxide 61, depositing the first metal oxide 61 on the side of the light-emitting layer 30 away from the anode 10 to obtain a metal oxide layer; using chemical vapor deposition, processing the side of the metal oxide layer away from the light-emitting layer 30 to form a metal nitride 63, to obtain a stacked first film layer and a second film layer.

[0056] By treating the surface of the metal oxide layer through chemical vapor deposition to form metal nitride 63, the element ratio in the film can be well controlled, the film uniformity is good, and the resulting film has better electrical properties.

[0057] Furthermore, atomic layer deposition (ALD) can be used to treat the side of the metal oxide layer facing away from the light-emitting layer 30. This allows for more precise control of the elemental composition and improves the film formation effect.

[0058] Furthermore, the step of using chemical vapor deposition to process the side of the metal oxide layer away from the light-emitting layer 30 to form metal nitride 63, thereby obtaining a stacked first and second film layers, includes: providing a nitrogen source and depositing the nitrogen source on the side of the metal oxide layer away from the light-emitting layer 30 using atomic layer deposition, so that the metal oxide layer is partially transformed into the second film layer, and the remaining metal oxide layer constitutes the first film layer; wherein, the material of the second film layer includes the metal nitride 63 or the metal nitride 63 and metal nitride 62, and the metal nitride 62 contains the same metal element as the first metal oxide 61. In this method, the metal oxide in the metal oxide layer is used as the metal element source to form metal nitride 63, avoiding the introduction of an additional metal element source, eliminating the step of removing excess metal element source and byproducts after the chemical adsorption reaction of an additional metal element source, reducing byproducts, and having the advantages of simple operation, high product purity, and better controllability. In addition, since the metal element is derived from the metal oxide in the metal oxide layer, when metal nitride 63 is formed, the concentration of metal cation defects at the interface can be increased, forming a buffer interface to capture some charge carriers and effectively blocking excess electrons from reaching the surface of the light-emitting layer 30.

[0059] Specifically, the step of depositing the nitrogen source on the side of the metal oxide layer away from the light-emitting layer 30 by atomic layer deposition includes: ionizing the nitrogen source with plasma to obtain ionized nitrogen, and depositing the ionized nitrogen on the side of the first film layer away from the light-emitting layer 30.

[0060] The nitrogen source is used to provide nitrogen element and may include, but is not limited to, one or more of nitrogen gas, nitrogen oxides, nitrogen dioxide, and ammonia.

[0061] The atomic layer deposition method is performed in a vacuum environment with a vacuum level of 10. -2 ~10 -3 Pa; for example, it can be 10. -3 Pa, 2×10 -3 Pa, 5×10 -3 Pa, 7×10 -3 Pa, 10 -2 Pa and the range between any two of the above values. This provides stable reaction conditions, allows for better control of the reaction process, achieves more precise deposition control, and improves product purity.

[0062] During the ionization process, the discharge power is 5 to 80 W; for example, it can be 5 W, 10 W, 15 W, 20 W, 25 W, 30 W, 35 W, 40 W, 45 W, 50 W, 55 W, 60 W, 65 W, 70 W, 75 W, 80 W, or any two of the above values. This allows for more precise control of the element ratio in the first electron transport layer 60.

[0063] During the ionization process, the discharge time is 10 to 20 seconds; for example, it can be 10 seconds, 11 seconds, 12 seconds, 13 seconds, 14 seconds, 15 seconds, 16 seconds, 17 seconds, 18 seconds, 19 seconds, 20 seconds, or any two of the above values. This allows for more precise control of the element ratio in the first electron transport layer 60.

[0064] Furthermore, in some embodiments, the target optoelectronic device 100 further includes a second electron transport layer 70. Correspondingly, the step of fabricating the first electron transport layer 60 on the side of the light-emitting layer 30 opposite to the anode 10 can be implemented by: fabricating at least one second electron transport layer 70 on the side of the light-emitting layer 30 opposite to the anode 10, and then fabricating the first electron transport layer 60 on the side of the at least one second electron transport layer 70 opposite to the light-emitting layer 30. For example, this can specifically include: providing a first metal oxide 61 and a second metal oxide; depositing the second metal oxide on the side of the light-emitting layer 30 opposite to the anode 10 to obtain at least one second electron transport layer 70; and depositing the first metal oxide 61 on the side of the at least one second electron transport layer 70 opposite to the light-emitting layer 30 to obtain a first film layer.

[0065] The second metal oxide may include one or more of undoped oxides and doped oxides. The undoped oxide includes one or more of ZnO, SnO2, and TiO2; the doped oxide includes an oxide doped with a dopant element, wherein the oxide includes one or more of ZnO, SnO2, and TiO2, and the dopant element includes one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu. In the doped metal oxide, the molar percentage of the dopant element is greater than 0 and less than or equal to 20%.

[0066] The methods for forming the metal oxide layer, the second electron transport layer 70, the anode 10, the cathode 20, the light-emitting layer 30, the hole transport layer 40, and the hole injection layer 50 can be chemical or physical methods. Chemical methods can include chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, and co-precipitation. Physical methods can include physical deposition or solution processing. Physical deposition methods include thermal evaporation deposition (CVD), electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition (PVD), atomic layer deposition, and pulsed laser deposition. Solution processing methods include spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating. Those skilled in the art can prepare the various film layers of the optoelectronic device 100 of this application embodiment according to the conventional methods for preparing optoelectronic devices 100, which will not be elaborated further here.

[0067] Furthermore, embodiments of this application also relate to a display device, which includes the optoelectronic device 100 provided in this application, or the optoelectronic device 100 prepared by the method described above. The display device can be any electronic product with display functionality, 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. Smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0068] The present application will be specifically described below through specific embodiments. These embodiments are only some embodiments of the present application and are not intended to limit the present application. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products.

[0069] Example 1

[0070] This embodiment provides a QLED device with a structure of ITO (80nm) / PEDOT:PSS (20nm) / TFB (20nm) / QD (40nm) / ETL1 (ZnO)+ETL2 (ZnNO+ZnN) (total thickness 35nm) / Al (100nm). The fabrication method is as follows:

[0071] Step S1: First, ultrasonically clean the ITO-coated substrate with acetone and ethanol for 15 minutes, then clean it again with deionized water, dry it on a heating plate at 150°C for 10 minutes, and finally irradiate it with ultraviolet light (UV) for 20 minutes.

[0072] Step S2: Place the substrate treated in S1 into a glove box and spin-coat an aqueous solution of PEDOT:PSS (mass fraction of 2.8%) onto ITO. Then heat it on a 150°C heating plate for 20 minutes to obtain the hole injection layer (HIL).

[0073] Step S3: Spin-coat a chlorobenzene solution of TFB (concentration of 6.5 mg / mL) onto the hole injection layer, and then heat it on a 120°C heating plate for 20 min to obtain the hole transport layer.

[0074] Step S4: Spin-coat a hexane solution of quantum dots (QDs) (concentration of 10 mg / mL) onto the hole transport layer, and then heat it on a 100°C heating plate for 5 min to obtain the light-emitting layer.

[0075] Step S5: Spin-coat ZnO (concentration of 20 mg / mL) in ethanol colloid onto the luminescent layer, and then heat it on an 80°C heating plate for 10 min to obtain a metal oxide layer with a thickness of approximately 35 nm.

[0076] A substrate with a deposited metal oxide layer is placed in the reaction chamber of an atomic layer apparatus, and a vacuum is drawn to 10⁻⁵. -2 Pa, nitrogen gas is ionized by plasma with a discharge power of 20W and a discharge time of 15s; a first electron transport layer is obtained, which is composed of a first film layer (ETL1) and a second film layer (ETL2) sequentially stacked on the light-emitting layer.

[0077] Step S6: Through thermal evaporation, the vacuum level is no higher than 3x10. -4 Pa was used to vaporize Al at a speed of 1 angstrom / second for 100 seconds, resulting in a thickness of 100 nm, thus obtaining a positive quantum dot light-emitting diode.

[0078] Example 2

[0079] This embodiment is basically the same as Embodiment 1, except that the device structure in this embodiment is ITO (80nm) / PEDOT:PSS (20nm) / TFB (20nm) / QD (40nm) / ETL1 (ZnMgO)+ETL2 (ZnMgNO+ZnMgN) (total thickness 35nm) / Al (100nm). Correspondingly, in step S5, ZnMgO (concentration of 20mg / mL) in ethanol colloid is spin-coated onto the light-emitting layer.

[0080] Example 3

[0081] This embodiment is basically the same as Embodiment 2, except that the device structure in this embodiment is ITO (80nm) / PEDOT: PSS (20nm) / TFB (20nm) / QD (40nm) / ETL3 (15nm) / ETL1 (ZnMgO)+ETL2 (ZnMgNO+ZnMgN) (total thickness 20nm) / Al (100nm). Correspondingly, in step S5, before preparing the metal oxide layer, the following is also included:

[0082] ZnMgO (concentration 20 mg / mL) in ethanol colloid was spin-coated onto the luminescent layer, and then heated on an 80°C hot plate for 10 min to obtain a second electron transport layer (ETL3) with a thickness of approximately 15 nm. The side of the second electron transport layer facing away from the luminescent layer was used to prepare the metal oxide layer.

[0083] Example 4

[0084] This embodiment is basically the same as Embodiment 2, except that this embodiment also has two second electron transport layers, and its device structure is ITO (80nm) / PEDOT: PSS (20nm) / TFB (20nm) / QD (40nm) / ETL3-2 (15nm) / ETL3-1 (15nm) / ETL1 (ZnMgO)+ETL2 (ZnMgNO+ZnMgN) (total thickness 10nm) / Al (100nm). Correspondingly, step S5 further includes the following before preparing the metal oxide layer:

[0085] A ZnMgO (20 mg / mL) ethanol colloid was spin-coated onto the luminescent layer, followed by heating at 80°C for 10 min to obtain a second electron transport layer ETL3-2 with a thickness of approximately 15 nm. A ZnO (20 mg / mL) ethanol colloid was then spin-coated again, followed by heating at 80°C for 10 min to obtain a second electron transport layer ETL3-1 with a thickness of approximately 15 nm. The side of the second electron transport layer ETL3-1 facing away from ETL3-2 was used to prepare the metal oxide layer.

[0086] Example 5

[0087] This embodiment is basically the same as embodiment 3, except that in step S5 of the preparation method in this embodiment, the discharge power is changed to 5W.

[0088] Example 6

[0089] This embodiment is basically the same as embodiment 3, except that the discharge power is changed to 80W in step S5 of the preparation method in this embodiment.

[0090] Example 7

[0091] This embodiment is basically the same as embodiment 3, except that the discharge power is changed to 85W in step S5 of the preparation method in this embodiment.

[0092] Example 8

[0093] This embodiment is basically the same as embodiment 3, except that in step S5 of this embodiment, the nitrogen source is changed to ammonia.

[0094] Example 9

[0095] This embodiment is basically the same as Embodiment 3, except that in step S5 of this embodiment, the ethanol colloid of ZnMgO (concentration of 20 mg / mL) is replaced with the ethanol colloid of TiO2 (concentration of 20 mg / mL). Accordingly, the device structure obtained is ITO (80 nm) / PEDOT:PSS (20 nm) / TFB (20 nm) / QD (40 nm) / ETL3 (TiO2, 15 nm) / ETL1 (TiO2)+ETL2 (TiNO+TiN) (total thickness 20 nm) / Al (100 nm).

[0096] Example 10

[0097] This embodiment is basically the same as Embodiment 3, except that in step S5 of this embodiment, the ethanol colloid of ZnMgO (concentration of 20 mg / mL) is replaced with the ethanol colloid of SnO2 (concentration of 20 mg / mL). Accordingly, the device structure obtained is ITO (80 nm) / PEDOT:PSS (20 nm) / TFB (20 nm) / QD (40 nm) / ETL3 (SnO2, 15 nm) / ETL1 (SnO2)+ETL2 (SnNO+SnN) (total thickness 20 nm) / Al (100 nm).

[0098] Example 11

[0099] This embodiment is basically the same as Embodiment 3, except that in this embodiment, a zinc source is added separately to prepare the second film layer ETL2 when preparing the metal nitride layer. Accordingly, step S5 is changed to:

[0100] ZnMgO (concentration of 20 mg / mL) in ethanol colloid was spin-coated onto the luminescent layer, and then heated on a heating plate at 80 °C for 10 min to obtain a first film layer with a thickness of about 15 nm.

[0101] The substrate with the first film deposited is placed in the reaction chamber of the atomic layer apparatus, and a vacuum is drawn to 10. -2 Pa was introduced, diethylzinc and diethylmagnesium were introduced, and nitrogen was ionized by plasma with a discharge power of 20W and a discharge time of 15s; a second film layer (ETL2) with a thickness of about 20nm was obtained.

[0102] Comparative Example 1

[0103] This comparative example is basically the same as Example 1, except that the step "placing the substrate with the deposited metal oxide layer into the reaction chamber of the atomic layer apparatus and evacuating to 10" is omitted in this comparative example. -2 Pa, nitrogen gas is ionized by plasma, with a discharge power of 20W and a discharge time of 15s; a first film layer (ETL1) and a second film layer (ETL2) are sequentially stacked on the light-emitting layer. The corresponding device structure is ITO (80nm) / PEDOT:PSS (20nm) / TFB (20nm) / QD (40nm) / ZnO (35nm) / Al (100nm).

[0104] Comparative Example 2

[0105] This comparative example is basically the same as Example 2, except that the step "placing the substrate with the deposited metal oxide layer into the reaction chamber of the atomic layer apparatus and evacuating to 10" is omitted in this comparative example. -2 Pa, nitrogen gas is ionized by plasma, with a discharge power of 20W and a discharge time of 15s; a first film layer (ETL1) and a second film layer (ETL2) are sequentially stacked on the light-emitting layer. The corresponding device structure is ITO (80nm) / PEDOT:PSS (20nm) / TFB (20nm) / QD (40nm) / ZnMgO (35nm) / Al (100nm).

[0106] Comparative Example 3

[0107] This comparative example is basically the same as Example 3, except that the step "placing the substrate with the deposited metal oxide layer into the reaction chamber of the atomic layer apparatus and evacuating to 10" is omitted in this comparative example. -2 Pa, nitrogen gas is ionized by plasma, with a discharge power of 20W and a discharge time of 15s; a first film layer (ETL1) and a second film layer (ETL2) are sequentially stacked on the light-emitting layer. The corresponding device structure is ITO (80nm) / PEDOT: PSS (20nm) / TFB (20nm) / QD (40nm) / ZnMgO (15nm) / ZnMgO (20nm) / Al (100nm).

[0108] Comparative Example 4

[0109] This comparative example is basically the same as Example 9, except that the step "placing the substrate with the deposited metal oxide layer into the reaction chamber of the atomic layer apparatus and evacuating to 10" is omitted in this comparative example. -2Pa, nitrogen gas is ionized by plasma, with a discharge power of 20W and a discharge time of 15s; a first film layer (ETL1) and a second film layer (ETL2) are sequentially stacked on the light-emitting layer. The corresponding device structure is ITO (80nm) / PEDOT: PSS (20nm) / TFB (20nm) / QD (40nm) / TiO2 (15nm) / TiO2 (thickness 20nm) / Al (100nm).

[0110] Comparative Example 5

[0111] This comparative example is basically the same as Example 10, except that the step "placing the substrate with the deposited metal oxide layer in the reaction chamber of the atomic layer apparatus and evacuating to 10" is omitted in this comparative example. -2 Pa, nitrogen gas is ionized by plasma, with a discharge power of 20W and a discharge time of 15s; a first film layer (ETL1) and a second film layer (ETL2) are sequentially stacked on the light-emitting layer. The corresponding device structure is ITO (80nm) / PEDOT: PSS (20nm) / TFB (20nm) / QD (40nm) / SnO2 (15nm) / SnO2 (20nm) / Al (100nm).

[0112] Experimental Example

[0113] (i) Following the method in step S5 of the above embodiments, a thin film composed of a first film layer and a second film layer was prepared on a glass substrate. The molar ratio of elements in the thin film was then detected by TEM-EDS, and the results are recorded in Table 1. Here, M represents a metal element; for example, in Example 1, M is Zn; in Examples 2 to 8 and Example 11, M is Zn and Mg; in Example 9, M is Ti; and in Example 10, M is Sn.

[0114] Table 1

[0115]

[0116]

[0117] (II) Performance tests were conducted on the QLED devices prepared in the above embodiments and comparative examples. The results are shown in Table 2. The testing methods are as follows:

[0118] (1) External quantum dot efficiency:

[0119] The ratio of electron-hole pairs injected into a quantum dot to emitted photons, expressed as a percentage (%), is an important parameter for evaluating the quality of electroluminescent devices. It can be measured using an EQE optical testing instrument. The specific calculation formula is as follows:

[0120]

[0121] Where ηe is the optical output coupling efficiency, ηr is the ratio of recombination carriers to injected carriers, χ is the ratio of the number of excitons generating photons to the total number of excitons, and K R K is the radiation process rate. NR This represents the rate of a non-radiative process.

[0122] Test conditions: Conducted at room temperature with an air humidity of 30-60%.

[0123] (2) Lifetime: The time required for the brightness of a device to decrease to a certain percentage of its maximum brightness under constant current or voltage driving. The time for the brightness to decrease to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. To shorten the testing cycle, device lifetime testing is usually performed by accelerating device aging under high brightness, referencing OLED device testing, and the lifetime under high brightness is obtained by fitting the extended exponential decay brightness decay fitting formula. For example, the lifetime at 1000 nits is measured as T95. 1000nit The specific calculation formula is as follows:

[0124]

[0125] In the formula, T95 L For longer lifespan at low brightness, T95 H For the measured lifetime under high brightness, L H To accelerate the device to its maximum brightness, L L The value is 1000 nits, and A is the acceleration factor. For OLEDs, this value is usually 1.6 to 2. In this experiment, the lifetime of several groups of QLED devices under rated brightness was measured, and the value of A was found to be 1.7.

[0126] The life test system was used to test the life of the corresponding devices. The test conditions were: room temperature and air humidity of 30-60%.

[0127] (3) Brightness and stability: The brightness of the device was measured and recorded as L. 0h The device was then operated at 8V for 50 hours and tested again, denoted as L. 50h Calculate the rate of change for each test item. Rate of change = (L) 0h -L 50h ) / L 50h *100%. The brightness L was measured using the following method: Under a test environment of 25℃ and 60% RH, the QLED devices prepared in each embodiment and comparative example were driven with a constant voltage of 8V, and a silicon photonics system was used to test the QLED devices at a current density of 10mA / m². 2 The brightness.

[0128] Table 2

[0129]

[0130]

[0131] As can be seen from the table above:

[0132] Examples 1 to 11 all exhibited low L change rates and high EQE and T95. 1000nit L 0h This demonstrates that the optoelectronic device proposed in this application has better stability, luminous performance, and lifespan;

[0133] Furthermore, Example 1 has higher EQE and T95 than Comparative Example 1. 1000nit L 0h Examples 2 through 8 and 11 have higher EQE and T95 values ​​than Comparative Examples 2 and 3, with a lower rate of change than Comparative Example 1. 1000nit L 0h The rate of change was lower than that of Comparative Examples 2 and 3, and Example 9 had a higher EQE and T95 than Comparative Example 4. 1000nit L 0h The rate of change was lower than that of Comparative Example 4, and Example 10 had a higher EQE and T95 than Comparative Example 5. 1000nit L 0h The rate of change was lower than that of Comparative Example 5, indicating that the addition of a metal nitride film layer helps to improve device stability, luminescence performance, and lifetime.

[0134] Furthermore, the performance of Example 3 is better than that of Example 11. This may be because Example 3 uses pre-deposited ZnMgO directly as a metal source, which increases the defect concentration, forms a buffer interface to capture some charge carriers, further promotes charge carrier balance, and reduces charge accumulation.

[0135] 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 a stacked anode, a light-emitting layer, a first electron transport layer, and a cathode. The first electron transport layer includes a first film layer and a second film layer stacked sequentially from the anode to the cathode. The material of the first film layer includes a first metal oxide, and the material of the second film layer includes a metal nitride.

2. The optoelectronic device according to claim 1, characterized in that, The first metal oxide comprises one or more of undoped oxides and doped oxides; the undoped oxide comprises one or more of ZnO, SnO2, and TiO2; the doped oxide comprises an oxide doped with a dopant element, wherein the oxide comprises one or more of ZnO, SnO2, and TiO2, and the dopant element comprises one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu; optionally, in the doped metal oxide, the molar percentage of the dopant element is greater than 0 and less than or equal to 20%; and / or, In the first electron transport layer, the metal element contained in the first metal oxide is the same as the metal element contained in the metal nitride; and / or, The thickness of the first electron transport layer is 5–40 nm; and / or, The material of the second film layer also includes metal nitride, wherein the metal nitride contains the same metal element as the first metal oxide.

3. The optoelectronic device according to claim 2, characterized in that, The metal nitride is distributed on the side of the second film layer facing the first film layer; and / or, The metal nitride is distributed on the side of the second film layer facing the cathode; and / or, In the direction from the anode to the cathode, the nitrogen content in the first electron transport layer gradually increases; and / or, In the direction from the anode to the cathode, the oxygen content in the first electron transport layer gradually decreases; and / or, In the first electron transport layer, the molar ratio of metal, nitrogen, and oxygen is 1:(0.1-0.3):(0.7-0.9).

4. The optoelectronic device according to claim 1, characterized in that, The optoelectronic device further includes at least one second electron transport layer disposed between the first electron transport layer and the light-emitting layer, wherein the material of each of the at least one second electron transport layer independently includes a second metal oxide.

5. The optoelectronic device according to claim 4, characterized in that, The thickness of the second electron transport layer is 15–30 nm; and / or, The optoelectronic device includes one or two layers of the second electron transport layer; and / or, The total thickness of the first electron transport layer and the second electron transport layer is 25–40 nm; and / or, The second metal oxide includes one or more of undoped oxides and doped oxides; the undoped oxide includes one or more of ZnO, SnO2, and TiO2; the doped oxide includes an oxide doped with a dopant element, wherein the oxide includes one or more of ZnO, SnO2, and TiO2, and the dopant element includes one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu; optionally, in the doped metal oxide, the molar percentage of the dopant element is greater than 0 and less than or equal to 20%.

6. The optoelectronic device according to claim 1, characterized in that, The material of the light-emitting layer includes organic light-emitting materials or quantum dots. The organic light-emitting materials include at least one of the following: diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, blue-emitting TBPe fluorescent materials, green-emitting TTPA fluorescent materials, orange-emitting TBRb fluorescent materials, and red-emitting DBP fluorescent materials. The quantum dots include at least one of the following: single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials. The shell of the core-shell structure quantum dots comprises one or more layers. The material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots respectively include group II-VI compounds and group IV-VI compounds. At least one of group II-V compounds and group I-III-VI compounds; said group II-VI compounds include 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, CdHgSeS, CdHgSeSe At least one of Te, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI compounds include at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V compounds include at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, and Ga At least one of NAs, 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 include at least one of CuInS2, CuInSe2, and AgInS2;The perovskite semiconductor material includes 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; + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of them; and / or, The anode and the cathode each independently include a doped metal oxide particle electrode, a metal and metal oxide composite electrode, a graphene electrode, a carbon nanotube electrode, or a metal electrode. The material of the doped metal oxide particle electrode is selected from 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 metal and metal oxide composite electrode is selected from 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, and ZnS / Al / ZnS. The material of the metal electrode is selected from one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg, and Ba.

7. A method for fabricating an optoelectronic device, characterized in that, Includes the following steps: It provides a stacked anode and light-emitting layer; A first electron transport layer is prepared on the side of the light-emitting layer opposite to the anode; A cathode is disposed on the side of the first electron transport layer opposite to the light-emitting layer; The fabrication of the first electron transport layer includes depositing a first metal oxide and a metal nitride on the side of the light-emitting layer away from the anode to obtain a stacked first film and a second film. The first film is disposed close to the light-emitting layer, and the material of the first film includes the first metal oxide, while the material of the second film includes the metal nitride.

8. The preparation method according to claim 7, characterized in that, The first metal oxide includes one or more of undoped oxides and doped oxides; the undoped oxide includes one or more of ZnO, SnO2, and TiO2; the doped oxide includes an oxide doped with a dopant element, wherein the oxide includes one or more of ZnO, SnO2, and TiO2, and the dopant element includes one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu; optionally, in the doped metal oxide, the molar percentage of the dopant element is greater than 0 and less than or equal to 20%; And / or, The step of depositing a first metal oxide and a metal nitride on the side of the light-emitting layer opposite to the anode to obtain a stacked first film layer and a second film layer includes: A first metal oxide is provided, and the first metal oxide is deposited on the side of the light-emitting layer opposite to the anode to obtain a metal oxide layer; Chemical vapor deposition is used to process the side of the metal oxide layer away from the light-emitting layer to form a metal nitride, resulting in a stacked first film layer and a second film layer.

9. The preparation method according to claim 8, characterized in that, The step of using chemical vapor deposition to process the side of the metal oxide layer away from the light-emitting layer to form a metal nitride, thereby obtaining a stacked first film and a second film, includes: providing a nitrogen source and depositing the nitrogen source on the side of the metal oxide layer away from the light-emitting layer using atomic layer deposition, so that a portion of the metal oxide layer is converted into the second film, and the remaining metal oxide layer constitutes the first film; wherein the material of the second film includes the metal nitride, or the material of the second film includes the metal nitride and metal oxynitride, wherein the metal oxynitride contains the same metal element as the first metal oxide.

10. The preparation method according to claim 9, characterized in that, The nitrogen source includes one or more of nitrogen gas, nitrogen oxides, nitrogen dioxide, and ammonia; and / or, The step of depositing the nitrogen source on the side of the metal oxide layer away from the light-emitting layer by atomic layer deposition includes: ionizing the nitrogen source with plasma to obtain ionized nitrogen, and depositing the ionized nitrogen on the side of the first film layer away from the light-emitting layer.

11. The preparation method according to claim 10, characterized in that, The atomic layer deposition method is performed in a vacuum environment with a vacuum level of 10. -2 ~10 -3 Pa; and / or, During the ionization treatment, the discharge power is 5–80 W; and / or, During the ionization treatment, the discharge time is 10 to 20 seconds.

12. The preparation method according to claim 7, characterized in that, In the step of fabricating a first electron transport layer on the side of the light-emitting layer opposite to the anode, the method further includes, before fabricating the first electron transport layer: The second metal oxide is deposited on the side of the light-emitting layer away from the anode to obtain at least one second electron transport layer, wherein the first electron transport layer is disposed on the side of the at least one second electron transport layer away from the light-emitting layer.

13. The preparation method according to claim 12, characterized in that, The second metal oxide includes one or more of undoped oxides and doped oxides; the undoped oxide includes one or more of ZnO, SnO2, and TiO2; the doped oxide includes an oxide doped with a dopant element, wherein the oxide includes one or more of ZnO, SnO2, and TiO2, and the dopant element includes one or more of Al, Mg, Li, In, Ga, Ti, Mn, Sn, Ag, and Cu; optionally, in the doped metal oxide, the molar percentage of the dopant element is greater than 0 and less than or equal to 20%.

14. A display device, characterized in that, It includes the optoelectronic device according to any one of claims 1 to 6, or the optoelectronic device prepared by the preparation method according to any one of claims 7 to 13.

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