Photoelectric device and preparation method thereof

Abstract

The invention discloses a photoelectric device and a preparation method thereof, the photoelectric device comprises an anode, a cathode and a functional layer, the anode and the cathode are oppositely arranged, the functional layer is arranged between the anode and the cathode, the functional layer comprises a first active layer and an auxiliary layer, the first active layer and the auxiliary layer are sequentially stacked, and the service life of the photoelectric device is prolonged through the auxiliary layer.

Description

Technical Field

[0001] This application relates to the field of optoelectronic technology, specifically to an optoelectronic device and its fabrication method. Background Technology

[0002] Optoelectronic devices refer to a class of devices made using the photoelectric effect of semiconductors, including but not limited to light-emitting devices, solar cells, or photodetectors. Taking light-emitting devices as an example, they include, but are not limited to, organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs). OLEDs / QLEDs have a "sandwich" structure, which includes an anode, a cathode, and a light-emitting layer. The anode and cathode are positioned opposite each other, and the light-emitting layer is positioned between the anode and cathode. The light-emitting principle of OLEDs / QLEDs is as follows: electrons are injected from the cathode into the light-emitting region, and holes are injected from the anode into the light-emitting region. Electrons and holes recombine in the light-emitting region to form excitons. The recombinated excitons release photons through radiative transitions, thereby emitting light.

[0003] After years of development, optoelectronic devices have made great progress in performance indicators and have shown great potential for application development. However, there are still shortcomings, and the lifespan of optoelectronic devices needs to be further improved. Summary of the Invention

[0004] This application provides an optoelectronic device and a method for fabricating the same, in order to improve the device lifespan of the optoelectronic device.

[0005] The technical solution of this application is as follows:

[0006] In a first aspect, this application provides an optoelectronic device, the optoelectronic device comprising:

[0007] The anode and cathode are arranged opposite each other; and

[0008] A functional layer is disposed between the anode and the cathode;

[0009] The functional layer comprises a first active layer and an auxiliary layer stacked sequentially. The first active layer is closer to the anode than the auxiliary layer. The material of the first active layer includes a first quantum dot. The material of the auxiliary layer includes nanoparticles with a core-shell structure. The core of the nanoparticles is a first metal oxide.

[0010] Secondly, this application provides a method for fabricating an optoelectronic device, the method comprising the following steps:

[0011] Provide a bottom electrode, and form a functional layer on one side of the bottom electrode; and

[0012] A top electrode is formed on the side of the functional layer away from the bottom electrode;

[0013] Wherein, when the optoelectronic device is a positively oriented structure, the bottom electrode is the anode and the top electrode is the cathode, and the step of forming a functional layer on one side of the bottom electrode includes the steps of: sequentially forming a first active layer and an auxiliary layer on one side of the bottom electrode; or, when the optoelectronic device is an inverted structure, the bottom electrode is the cathode and the top electrode is the anode, and the step of forming a functional layer on one side of the bottom electrode includes the steps of: sequentially forming an auxiliary layer and a first active layer on one side of the bottom electrode;

[0014] The material of the first active layer includes a first quantum dot; the material of the auxiliary layer includes nanoparticles with a core-shell structure, wherein the core of the nanoparticles is a first metal oxide.

[0015] This application provides an optoelectronic device, a method for fabricating the optoelectronic device, and an electronic device, which have the following technical advantages:

[0016] In the optoelectronic device of this application, an auxiliary layer is introduced between the first active layer and the cathode, and the auxiliary layer improves the device lifetime of the optoelectronic device. Attached Figure Description

[0017] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the structure of the first optoelectronic device provided in the embodiments of this application.

[0019] Figure 2 This application provides a schematic diagram of the structure of a second type of optoelectronic device.

[0020] Figure 3 This is a schematic diagram of the structure of the first active layer, auxiliary layer and second active layer in the optoelectronic device provided in the embodiments of this application.

[0021] The attached figures are labeled as follows:

[0022] 10: Optoelectronic device; 101: Anode; 102: Cathode; 103: Functional layer; 110: Nanoparticle; 111: First quantum dot; 112: Second quantum dot; 1031: First active layer; 1032: Auxiliary layer; 1033: Second active layer; 1034: Hole functional layer; 1035: Electron functional layer; 1101: Core; 1102: Shell; 10341: Hole injection layer; 10342: Hole transport layer. Detailed Implementation

[0023] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0025] It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of embodiments. 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 rigid limitation on the scope of the invention; 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 indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0026] In the description of this application, the term "comprising" means "including but not limited to".

[0027] The term "at least one" refers to one or more items, while "multiple" or "multi-item" refers to two or more items. The terms "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 be expressed as: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0028] The term "and / or" encompasses any one of two or more of the listed items, as well as any and all combinations of the listed items. These combinations include any two listed items, any number of listed items, or a combination of all listed items. For example, "A and / or B" includes three parallel solutions: A, B, and A+B. Similarly, the technical solution "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (i.e., all connected by "logical OR"), any and all combinations of A, B, C, and D, including combinations of any two or three of A, B, C, and D, and combinations of all four of A, B, C, and D (i.e., all connected by "logical AND").

[0029] In this application, descriptions such as "layer A is formed on one side of layer B," "layer A is formed on the side of layer B away from layer C," or similar expressions can mean that layer A is directly formed on one side of layer B or on the side of layer B away from layer C, i.e., layer A and layer B are in direct contact; or they can mean that layer A is indirectly formed on one side of layer B or on the side of layer B away from layer C, i.e., other spacer structures can be formed between layer A and layer B. Similarly, "layer A is disposed on one side of layer B" or "layer A is disposed on the side of layer B away from layer C" can mean that layer A and layer B are in direct contact, or that other spacer structures are provided between layer A and layer B; "layer A is disposed between layer B and layer C" can mean that layer A and layer B are in direct contact and layer A and layer C are in direct contact, or layer A and layer B are in direct contact and one or more spacer structures are provided between layer A and layer C, or layer A and layer B are provided and one or more spacer structures are provided between layer A and layer C, or layer A and layer B are provided and layer A and layer C are in direct contact.

[0030] The term "particle size" refers to the diameter of nanoparticles.

[0031] The term "aliphatic chain hydrocarbon group" refers to an aliphatic straight-chain hydrocarbon group or an aliphatic branched hydrocarbon group. "A chain hydrocarbon group having 1 to 6 carbon atoms" can be, for example, a straight-chain alkyl group having 1 to 6 carbon atoms, a straight-chain alkenyl group having 2 to 6 carbon atoms, a straight-chain alkynyl group having 2 to 6 carbon atoms, a branched alkyl group having 2 to 6 carbon atoms, a branched alkenyl group having 4 to 6 carbon atoms, or a branched alkynyl group having 4 to 6 carbon atoms. The number of carbon atoms in a chain hydrocarbon group having 1 to 6 carbon atoms can be, for example, 1 to 3, 1 to 4, 2 to 4, or 2 to 5, with examples being 1, 2, 3, 4, 5, or 6. "A chain hydrocarbon group having 8 to 30 carbon atoms" can be, for example, a straight-chain alkyl group having 8 to 30 carbon atoms, a straight-chain alkenyl group having 8 to 30 carbon atoms, a straight-chain alkynyl group having 8 to 30 carbon atoms, a branched alkyl group having 8 to 30 carbon atoms, a branched alkenyl group having 8 to 30 carbon atoms, or a branched alkynyl group having 8 to 30 carbon atoms. The number of carbon atoms in a chain hydrocarbon group having 8 to 30 carbon atoms can be, for example, 8 to 10, 8 to 15, 8 to 20, 10 to 20, or 15 to 20, with examples being 8, 10, 15, 20, 25, 30, or a value between any two of the aforementioned values.

[0032] The term "aliphatic chain alkyl group" refers to a group with the general formula *-O-chain alkyl group, where * represents the linking site and O represents the oxygen atom.

[0033] The applicant discovered that some optoelectronic devices suffer from an imbalance in electron-hole transport, resulting in poor device efficiency and lifetime. For example, QLED devices, especially blue QLED devices, exhibit a much higher electron injection level than hole injection level. This is due to two main reasons: First, because quantum dots are N-type semiconductors, their electron transport capability is far stronger than their hole transport capability. Second, while organic-inorganic hybrid QLED devices with organic hole transport layers combined with inorganic electron transport layers offer better performance, the organic hole transport layer has a lower hole mobility, and there is a large hole injection barrier between the organic hole transport layer and the quantum dot light-emitting layer, leading to a lower hole injection level. In contrast, the inorganic electron transport layer has a lower electron injection barrier and higher mobility, resulting in an imbalance in electron-hole transport.

[0034] Based on this, this application provides an optoelectronic device, which includes, but is not limited to, light-emitting devices, solar cells, or photodetectors, such as... Figures 1 to 3As shown, the optoelectronic device 10 includes an anode 101, a cathode 102, and a functional layer 103. The functional layer 103 is disposed between the anode 101 and the cathode 102. The functional layer 103 includes a first active layer 1031 and an auxiliary layer 1032 stacked sequentially. The first active layer 1031 is closer to the anode 101 than the auxiliary layer 1032. The material of the first active layer 1031 includes a first quantum dot 111. The material of the auxiliary layer 1032 includes nanoparticles 110 with a core-shell structure. The material of the core 1101 of the nanoparticles 110 is a first metal oxide.

[0035] In the optoelectronic device 10 of this application embodiment, an auxiliary layer 1032 is introduced between the first active layer 1031 and the cathode 102, which can improve the device life of the optoelectronic device 10.

[0036] To enhance the stability of the nanoparticles 110, in some embodiments of this application, the shell 1102 of the nanoparticles 110 is made of an insulating compound to promote electron-hole transport balance. The shell 1102 of the nanoparticles 110 is made of one or more materials selected from silicon oxides and silicon nitrides, for example, silicon dioxide.

[0037] In some embodiments of this application, the shell 1102 of the nanoparticle 110 partially covers the core 1101 of the nanoparticle 110. While ensuring a good electron injection level, the shell 1102 of the nanoparticle 110 can block excessive electron injection into the first active layer 1031 and slow down the rate of electron injection into the first active layer 1031, thereby reducing the electron injection level, promoting electron-hole transport balance, and thus improving the device lifetime of the optoelectronic device 10. The average coverage rate of the shell 1102 of the nanoparticle 110 to the core 1101 of the nanoparticle 110 is, for example, 30% to 70%, with examples being 30%, 40%, 50%, 60%, 70%, or any value between the aforementioned two values.

[0038] To further promote the electron-hole transport balance of the optoelectronic device 10, further reference is made to some embodiments of this application. Figure 3 For the core 1101 of nanoparticle 110, compared to the portion covered by the shell 1102 of nanoparticle 110, the portion not covered by the shell 1102 of nanoparticle 110 is closer to the first active layer 1031, so as to ensure that the optoelectronic device 10 has a good electron injection level and further block excessive electron injection.

[0039] In order to ensure that the optoelectronic device 10 has a good electron injection level and improve the matching degree between the electron injection level and the hole injection level, in some embodiments of this application, the mass of the shell 1102 accounts for 5% to 15% of the total mass of the nanoparticles 110, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15% or any two of the aforementioned values; and / or, the average particle size of the nanoparticles is 3nm to 10nm, for example, it can be 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm or any two of the aforementioned values; and / or, the oxygen atoms in the first metal oxide are connected to the insulating compound by covalent bonds.

[0040] To ensure that the optoelectronic device 10 has a good electron injection level, in some embodiments of this application, the first metal oxide is selected from one or more of the following: zinc oxide, titanium oxide, tin oxide, barium oxide, tantalum oxide, aluminum oxide, zirconium oxide, zinc magnesium oxide, zinc calcium oxide, zinc zirconium oxide, zinc gallium oxide, zinc aluminum oxide, zinc lithium oxide, zinc titanium oxide, yttrium zinc oxide, indium tin oxide, and lithium titanium oxide, such as ZnO, TiO2, SnO2, BaO, Ta2O3, Al2O3, ZrO2, and Zn. (1-x) Mg x O, Zn (1-x) Ca x O, Zn (1-x) Zr x O, Zn (1-x) Ga x O, Zn (1-x) Al x O, Zn (1-x) Li x O, Al (1-x) Zn x O, Zn (1-x) Ti x O, Zn (1-x) Y x O、In (1-x) Sn x O and Ti (1-x) Li x One or more of O, where 0 < x ≤ 0.5.

[0041] In order to further ensure that the optoelectronic device 10 has a good electron injection level and improve the matching degree between the electron injection level and the hole injection level, in some embodiments of this application, the nanoparticles 110 of the auxiliary layer 1032 are arranged in a single layer, so as not to have a negative impact on the electron conduction process of the optoelectronic device.

[0042] In order to balance improving the photoelectric performance of the optoelectronic device 10 and reducing manufacturing costs, in some embodiments of this application, for Figure 1 The optoelectronic device 10 shown has a first active layer 1031 with a thickness of 8nm to 60nm, for example, 8nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, or any value between any two of the aforementioned values; and / or, an auxiliary layer 1032 with a thickness of 3nm to 10nm, for example, 3nm, 5nm, 8nm, 10nm, or any value between any two of the aforementioned values.

[0043] To further improve the solution processing performance of the first quantum dot 111 and / or nanoparticles 110, in some embodiments of this application, a first ligand is attached to the surface of the first quantum dot 111, and / or a second ligand is attached to the uncoated portion of the core 1101 of the nanoparticle 110, and / or a third ligand is attached to the surface of the shell 1102 of the nanoparticle 110. The first to third ligands are independently selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, and -NO2 groups, respectively. And one or more of the ligands of the general formula L1-L2, where X is a halogen atom and L2 is a coordinating group.

[0044] Wherein, L1 is independently selected each time from an unsubstituted or substituted-within-at least one first group aliphatic chain hydrocarbon group having 1 to 30 carbon atoms, an unsubstituted or substituted-within-at least one first group aliphatic chain hydroxyl group having 1 to 30 carbon atoms, an unsubstituted or substituted-within-at least one first group aliphatic cyclic hydrocarbon group having 3 to 30 ring atoms, an unsubstituted or substituted-within-at least one first group aliphatic heterocyclic hydrocarbon group having 3 to 30 ring atoms, an unsubstituted or substituted-within-at least one first group aryl group having 6 to 30 ring atoms, an unsubstituted or substituted-within-at least one first group aryloxy group having 6 to 30 ring atoms, an unsubstituted or substituted-within-at least one first group heteroaryl group having 5 to 30 ring atoms, or an unsubstituted or substituted-within-at least one first group heteroaryloxy group having 5 to 30 ring atoms, or a combination of these groups. The first group is independently selected each time from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, -NO2. Or combinations of these groups. R1 through R7 are each independently selected from an aliphatic chain hydrocarbon group having 1 to 10 carbon atoms, an aliphatic chain alkyl group having 1 to 10 carbon atoms, an aliphatic cyclic hydrocarbon group having 3 to 10 ring atoms, an aliphatic heterocyclic hydrocarbon group having 3 to 10 ring atoms, an aryl group having 6 to 14 ring atoms, an aryloxy group having 6 to 14 ring atoms, a heteroaryl group having 5 to 14 ring atoms, or a heteroaryloxy group having 5 to 14 ring atoms, or combinations of these groups. L2 is each independently selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, -NO2. Or a combination of these groups.

[0045] To further improve the device lifetime of the optoelectronic device 10, in some embodiments of this application, the first ligand includes a coordination end and a free end. The coordination end of the first ligand is connected to the surface of the first quantum dot 111, and the free end of the first ligand has a first electrical property. The second ligand includes a coordination end and a free end. The coordination end of the second ligand is connected to the uncoated portion of the core 1101 of the nanoparticle 110, and the free end of the second ligand has a second electrical property. One of the first electrical property and the second electrical property is positively charged, and the other is negatively charged, so that the uncoated portion of the core 1101 of the nanoparticle 110 and the first quantum dot 111 are attracted to each other through Coulomb interaction, which can prevent excessive electrons and / or excitons from transferring to the anode 101.

[0046] To further improve the device efficiency of the optoelectronic device 10, in some embodiments of this application, a third ligand is attached to the surface of the shell 1102 of the nanoparticle 110. The third ligand includes a coordination end and a free end. The coordination end of the third ligand is connected to the surface of the shell 1102 of the nanoparticle 110. The free end of the third ligand is electrically neutral or has a third electrical property. The first electrical property is the same as the third electrical property, that is, the second electrical property is opposite to the third electrical property. The first ligand and the third ligand can be the same or different. For the core 1101 of the nanoparticle 110, compared with the part not covered by the shell 1102 of the nanoparticle 110, the part covered by the shell 1102 of the nanoparticle 110 is closer to the first active layer 1031, which improves the fluorescence quenching phenomenon that is prone to occur due to the direct contact between the part of the core 1101 not covered by the shell 1102 and the first quantum dot 111.

[0047] To further promote electron-hole transport balance, in some embodiments of this application, the first ligand and the third ligand are independently selected from electron-withdrawing groups or ligands of the general formula L1-L2, and the second ligand is selected from electron-donating groups or ligands of the general formula L1-L2. Specifically, in the first ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, with each occurrence of the first group independently selected from an electron-withdrawing group; in the third ligand, L1 is selected from an aliphatic chain hydrocarbon group having 8 to 30 carbon atoms substituted by at least one first group, with each occurrence of the first group independently selected from an electron-withdrawing group; in the second ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, with each occurrence of the first group independently selected from an electron-donating group. It should be noted that the shorter carbon chain length of the first and second ligands is beneficial for increasing the hole injection level; the longer carbon chain length of the third ligand can block excessive electron injection and promote electron-hole transport balance.

[0048] To further promote electron-hole transport balance, in some embodiments of this application, the first ligand and the third ligand are independently selected from electron-donating groups or ligands of the general formula L1-L2, and the second ligand is selected from electron-withdrawing groups or ligands of the general formula L1-L2; in the first ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, and the first group is independently selected from an electron-donating group each time it appears; in the third ligand, L1 is selected from an aliphatic chain hydrocarbon group having 8 to 30 carbon atoms substituted by at least one first group, and the first group is independently selected from an electron-donating group each time it appears; in the second ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, and the first group is independently selected from an electron-withdrawing group each time it appears.

[0049] In at least one embodiment of this application, the first ligand and the third ligand are independently selected from carboxyl, -NO2, aldehyde, or ligands of general formula L1-L2, respectively; the second ligand is selected from hydroxyl, -OCH3, or ligands of general formula L1-L2; and in the first ligand and the third ligand, each occurrence of the first group is independently selected from carboxyl, -NO2, or aldehyde, and each occurrence of L2 is independently selected from carboxyl, -NO2, or aldehyde; and in the second ligand, each occurrence of the first group is independently selected from hydroxyl or -OCH3, and L2 is selected from hydroxyl or -OCH3.

[0050] In at least one embodiment of this application, the first ligand and the third ligand are independently selected from hydroxyl, -OCH3, or ligands of general formula L1-L2, respectively, and the second ligand is selected from hydroxyl, -OCH3, or ligands of general formula L1-L2. In the first ligand and the third ligand, the first group is independently selected from hydroxyl or -OCH3 each time it appears, and L2 is independently selected from hydroxyl or -OCH3 each time it appears. In the second ligand, the first group is independently selected from carboxyl, -NO2, or aldehyde each time it appears, and L2 is selected from carboxyl, -NO2, or aldehyde.

[0051] To further promote the electron-hole transport balance of the optoelectronic device 10, in some embodiments of this application, the first quantum dot 111 is connected to the uncoated portion of the core 1101 of the nanoparticle 110 via a first ligand and / or a second ligand, so that for the core 1101 of the nanoparticle 110, the portion coated by the shell 1102 is closer to the first active layer 1031 than the portion uncoated by the shell 1102, and the binding tightness between the first active layer 1031 and the auxiliary layer 1032 is improved. It is understood that at least one of the first ligand and / or the second ligand is selected from ligands of the general formula L1-L2, that is, at least one of the first ligand and the second ligand has two or more coordination groups. When the first ligand or the second ligand has two or more coordination groups, the coordination groups may be the same or different, and at least one coordination group can be coordinated to the surface of the first quantum dot 111, and at least one coordination group can be coordinated to the portion covered by the shell 1102 of the nanoparticle 110.

[0052] The first ligand and the second ligand are, for example, independently selected from one or more of the following: aliphatic polyols having 1 to 4 carbon atoms, aliphatic polyacids having 2 to 4 carbon atoms, aliphatic polythiols having 1 to 4 carbon atoms, and aliphatic polyamines having 1 to 4 carbon atoms. The aliphatic polyols having 1 to 4 carbon atoms include, but are not limited to, one or more of ethylene glycol, propylene glycol, glycerol, and butanediol; the aliphatic polyacids having 2 to 4 carbon atoms include, but are not limited to, one or more of oxalic acid, malonic acid, and succinic acid; the aliphatic polythiols having 1 to 4 carbon atoms include, but are not limited to, one or more of ethylenedithiol, propylenedithiol, and butylenedithiol; and the aliphatic polyamines having 1 to 4 carbon atoms include, but are not limited to, one or more of ethylenediamine, propylenediamine, and butylenediamine.

[0053] As an example, the first ligand and the second ligand are each independently selected from one or more of dimethylamine, ethylene glycol, oxalic acid, ethylenedithiol, ethylenediamine, oxalic acid, 2-mercaptoethanol, 1,3-propanediol, malonic acid, 3-mercapto-1-propanol, 1,3-dimercaptopropane, and propylenediamine.

[0054] To further improve the device efficiency and device lifetime of the optoelectronic device 10, in some embodiments of this application, such as... Figure 2 As shown, the functional layer 103 further includes a second active layer 1033, which is disposed on the side of the auxiliary layer 1032 away from the first active layer 1031. The material of the second active layer 1033 includes a second quantum dot 112. The second active layer 1033 can further block excess electron injection into the first active layer 1031, further promote electron-hole transport balance, and ensure that the optoelectronic device 10 has good luminous efficiency.

[0055] To further reduce the electron injection level, in some embodiments of this application, the surface of the second quantum dot 112 is connected to a fourth ligand, which is selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, -NO2, etc. Alternatively, ligands of the general formula L1-L2; L1 is selected from unsubstituted or substituted aliphatic chain hydrocarbons having 8 to 30 carbon atoms, and L2 is the coordinating group; L2 and the first group are independently selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, -NO2, etc. R1 through R7 are each independently selected from aliphatic chain hydrocarbon groups having 1 to 10 carbon atoms. The fourth ligand has a longer carbon chain, which can block excess electrons and / or slow down the electron injection rate.

[0056] To ensure that the optoelectronic device 10 has a good electron injection level and further block excessive electron injection, in some embodiments of this application, for the core 1101 of the nanoparticle 110, the portion covered by the shell 1102 of the nanoparticle 110 is closer to the second active layer 1033 than the portion not covered by the shell 1102 of the nanoparticle 110.

[0057] To further promote the electron-hole transport balance of the optoelectronic device 10, in some embodiments of this application, the shell 1102 of the nanoparticle 110 is connected to the second quantum dot 112 via a third ligand and / or a fourth ligand. This ensures that the portion of the nanoparticle 110 covered by the shell 1102 is closer to the second active layer 1033 than the portion not covered by the shell 1102, and improves the bonding tightness between the auxiliary layer 1032 and the second active layer 1033. The third ligand and / or the fourth ligand each independently have at least two coordinating groups, which include, but are not limited to, -NR3R4, carboxyl, thiol, or hydroxyl groups. When the third or fourth ligand has two or more coordinating groups, the coordinating groups may be the same or different, and at least one coordinating group can be coordinatingly connected to the surface of the second quantum dot 112 and at least one coordinating group can be coordinatingly connected to the shell 1102.

[0058] The third and fourth ligands are, for example, independently selected from one or more of the following: aliphatic polyols, aliphatic polyacids, aliphatic polythiols, and aliphatic polyamines, each having 8 to 20 carbon atoms. The number of carbon atoms in the third or fourth ligand can be 8 to 10, 8 to 12, 8 to 15, 10 to 15, or 15 to 20. Among them, aliphatic polyols with 8 to 20 carbon atoms include, but are not limited to, one or more of 1,8-octanediol, 1,9-nonanediol, 1,4,8-octanediol and 1,10-decanediol; aliphatic polyacids with 8 to 20 carbon atoms include, but are not limited to, one or more of octanediic acid, azelaic acid and sebacic acid; aliphatic polythiols with 8 to 20 carbon atoms include, but are not limited to, one or more of 1,8-octanedithiol, 1,9-nonanedithiol and 1,10-decanedithiol; and aliphatic polyamines with 8 to 20 carbon atoms include, but are not limited to, one or more of octanediamine, nonanediamine and decanediamine.

[0059] As an example, the third and fourth ligands are independently selected from one or more of 1,8-octanediamine, 1,9-diaminononane, decanediamine, 1,11-diaminoundecane, 1,12-diaminododecane, octanoic acid, azelaic acid, sebacic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, undecenoic acid, 2-dodecenoic acid, octanediol, nonanediol, decanediol, dodecanediol, tetradecanediol, hexadecanediol, octadecanediol, octanedithiol, nonanedithiol, decanedithiol, 8-amino-1-octanol, and 10-amino-1-decethiol.

[0060] To further improve the photoelectric performance and device lifetime of optoelectronic devices, in some embodiments of this application, for Figure 3 The optoelectronic device 10 shown has a thickness ratio of the first active layer 1031 to the second active layer 1033 of 1:(1 to 5), for example, it can be 1:1, 1:2, 1:3, 1:4, 1:5 or any two of the aforementioned ratios; and / or, the thickness of the first active layer 1031 is 8nm to 15nm, for example, it can be 8nm, 10nm, 15nm or any two of the aforementioned values; and / or the first quantum dots in the first active layer 1031 are arranged in a single layer; and / or, the thickness of the second active layer 1033 is 8nm to 45nm, for example, it can be 8nm, 10nm, 20nm, 30nm, 45nm or any two of the aforementioned values; and / or, the thickness of the auxiliary layer 1032 is 3nm to 10nm, for example, it can be 3nm, 5nm, 8nm, 10nm or any two of the aforementioned values.

[0061] In the optoelectronic device 10 of this application embodiment, the first quantum dot 111 or the second quantum dot 112 is, but is not limited to, one or more of red quantum dots, green quantum dots, and blue quantum dots. Furthermore, the first quantum dot 111 or the second quantum dot 112 is, but is not limited to, one or more of single-component quantum dots, core-shell structured quantum dots, inorganic perovskite quantum dots, organic perovskite quantum dots, and organic-inorganic hybrid perovskite quantum dots. The shell of the core-shell structured quantum dot can be one or more layers. The average particle size of the quantum dots can be, for example, 2nm to 20nm, with examples being 2nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 15nm, 20nm, or any value between any two of the aforementioned values.

[0062] For single-component quantum dots and core-shell quantum dots, the material of the single-component quantum dot, the material of the core of the core-shell quantum dot, or the material of the shell of the core-shell quantum dot includes, but is not limited to, at least one of group II-VI compounds, group III-V compounds, group III-VI compounds, group IV-VI compounds, or group I-III-VI compounds. Among them, the II-VI group compounds include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. III-VI group compounds include, but are not limited to, one or more of In2S3, In2Se3, InGaS3, and InGaSe3. III-V group compounds 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. Group IV-VI compounds 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. Group I-III-VI compounds include, but are not limited to, one or more of AgInS, AgInS2, CuInS, CuInS2, AgGaS2, CuGaS2, CuGaO2, AgGaO2, AgAlO2, AgInGaS2, and CuInGaS2.

[0063] It should be noted that for the aforementioned single-component quantum dot materials, or the core materials of core-shell quantum dot materials, or the shell materials of core-shell quantum dot materials, the provided chemical formulas only indicate the elemental composition, not the content of each element. For example, CdZnSe only indicates that it is composed of three elements: Cd, Zn, and Se. If the content of each element were specified, it would correspond to Cd... x Zn 1-x Se, 0 <x<1。

[0064] For inorganic perovskite quantum dots, the general structural formula is AMX3, where A is Cs. + M is a divalent metal cation, and M includes, but is not limited to, Pb. 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Or Eu 2+ X is a halide anion, including but not limited to Cl-, Br-, or I-. - .

[0065] For organic perovskite quantum dots, the general structural formula is CMX3, where C is a formamidinyl group and M is a divalent metal cation, which may include, but is not limited to, Pb. 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Or Eu 2+ X is a halide anion, including but not limited to Cl. - ,Br - Or I - .

[0066] For organic-inorganic hybrid perovskite quantum dots, the general structural formula is BMX3, where B is selected from organic amine cations, including but not limited to CH3(CH2). n-2 NH 3+ (n≥2) or NH3(CH2) n NH3 2+(n≥2), M is a divalent metal cation, and M includes, but is not limited to, Pb. 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Or Eu 2+ X is a halide anion, including but not limited to Cl. - ,Br - Or I - .

[0067] In some embodiments of this application, the ligands that are only surface-connected between the first quantum dot 111 and the second quantum dot 112 are different.

[0068] In some embodiments of this application, the materials of the anode 101 and the cathode 102 are independently selected from one or more of metals, carbon materials, and second metal oxides. The metals include, but are not limited to, one or more of Al, Ag, Cu, Mo, Au, Ba, Pt, Ca, Ir, Ni, and Mg. The carbon materials include, but are not limited to, one or more of graphite, carbon nanotubes, graphene, and carbon fibers. The second metal oxides include, but are not limited to, one or more of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), SnO2, ZnO, and In2O3. The anode 101 or cathode 102 can also be a composite electrode, which has a sandwich-like structure. The upper and lower layers are made of doped or undoped transparent metal oxides, respectively, and the middle layer is made of metal, such as 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, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2. The thickness of the middle layer does not exceed 35 nm. The thickness of the anode 101 can be, for example, 20 nm to 300 nm, and the thickness of the cathode 102 can be, for example, 20 nm to 300 nm.

[0069] To further improve the photoelectric performance and device lifespan of the optoelectronic device 10, further reference is made to some embodiments of this application. Figure 1 and Figure 3 The optoelectronic device 10 further includes a hole functional layer 1034, which is disposed between the anode 101 and the first active layer 1031. The hole functional layer 1034 can be a single-layer structure or a multi-layer structure, and its thickness is, for example, 10 nm to 100 nm. When the hole functional layer 1034 is a multi-layer structure, it may include one or more of a hole injection layer, a hole transport layer, and an electron blocking layer. For a hole functional layer 1034 including a hole injection layer, a hole transport layer, and an electron blocking layer, the hole transport layer is located between the hole injection layer and the electron blocking layer, and the hole injection layer is closer to the anode 101 than the electron blocking layer. For a hole functional layer 1034 including a hole transport layer and an electron blocking layer, the hole transport layer is closer to the anode 101 than the electron blocking layer. For a hole functional layer 1034 including a hole injection layer and a hole transport layer, the hole injection layer is closer to the anode 101 than the hole transport layer.

[0070] The hole functional layer 1034 is made of one or more of the following: undoped first inorganic compound, doped second inorganic compound, and organic compound. The organic compound includes, but is not limited to, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS, CAS No. 155090-83-8), copper phthalocyanine (CAS No. 147-14-8), titanium phthalocyanine (CAS No. 26201-32-1), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (CAS No. 29261-33-4), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (CAS No. 105598-27-4), and polyaniline (CAS No. 25233-30-1). Polypyrrole (CAS No. 30604-81-0), 3-hexyl-substituted polythiophene (CAS No. 104934-50-1), poly(9-vinylcarbazole) (abbreviated as PVK, CAS No. 25067-59-8), 4,4'-bis(9-carbazole)biphenyl (abbreviated as CBP, CAS No. 58328-31-7), poly[bis(4-phenyl)(4-butylphenyl)amine], 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (abbreviated as TAPC, CAS No. 58473-78-2), poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)di- 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (CAS No. 124729-98-2), 4,4',4'-tris(carbazole-9-yl)triphenylamine (CAS No. 139092-78-7), 4,4',4'-tris(2-naphthylphenylamino)triphenylamine (CAS No. 185) 690-41-9), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (abbreviated as NPB, CAS number 123847-85-8), N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (abbreviated as TPD, CAS number 65181-78-4), N,N'-bis[4-(diphenylamino)phenyl]-N,N'-diphenylbenzidine (CAS number 209980-53-0), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-9,9-spirodifluorene-2,7-diamine (abbreviated as Spiro-TPD),One or more of the following: CAS No. 1033035-83-4, N2,N7-di-1-naphthyl-N2,N7-diphenyl-9,9'-spirobis[9H-fluorene]-2,7-diamine (CAS No. 932739-76-9), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTTA, CAS No. 1333317-99-9), and 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobisfluorene (Spiro-omeTAD, CAS No. 207739-72-8); and / or, the undoped first inorganic compound includes, but is not limited to, graphene, C60, nickel oxide (e.g., NiO), molybdenum oxide (e.g., MoO3), tungsten oxide (e.g., WO3), vanadium oxide (e.g., V2O5), and p-type nitride. Gallium, chromium oxide (e.g., Cr2O3), copper oxide (e.g., CuO or Cu2O), copper sulfide (e.g., CuS), molybdenum sulfide (e.g., MoS2), and tungsten sulfide (e.g., WS2) are selected as one or more of the following: gallium, chromium oxide (e.g., Cr2O3), copper oxide (e.g., CuO or Cu2O), copper sulfide (e.g., CuS), molybdenum sulfide (e.g., MoS2), and tungsten sulfide (e.g., WS2); and / or the doped second inorganic compound is a host inorganic compound doped with a second doping element, the host inorganic compound including but not limited to graphene, C60, nickel oxide (e.g., NiO), molybdenum oxide (e.g., MoO3), tungsten oxide (e.g., WO3), vanadium oxide (e.g., V2O5), p-type gallium nitride, chromium oxide (e.g., Cr2O3), copper oxide (e.g., CuO or Cu2O), copper sulfide (e.g., CuS), molybdenum sulfide (e.g., MoS2), and tungsten sulfide (e.g., WS2), and / or the second doping element including but not limited to nickel, molybdenum, tungsten, vanadium, chromium, copper, and platinum group metals.

[0071] It is understood that when the hole functional layer 1034 comprises multiple materials and the hole functional layer 1034 has a multi-layer structure, the multiple materials can all be in the same layer, or in different layers, or partially in the same layer. For example, as Figure 1 and Figure 2 As shown, when the hole functional layer 1034 is composed of a hole injection layer 10341 and a hole transport layer 10342 stacked together, the material of the hole functional layer 1034 includes PEDOT:PSS and TFB, with PEDOT:PSS and TFB located in different layers. The material of the hole injection layer 10341 is PEDOT:PSS, and the material of the hole transport layer 10342 is TFB.

[0072] To further improve the photoelectric performance and device lifespan of the optoelectronic device 10, further reference is made to some embodiments of this application. Figure 1 and Figure 2The optoelectronic device 10 further includes an electronic functional layer 1035, which is disposed between the cathode 102 and the auxiliary layer 1032. The electronic functional layer 1035 can be a single-layer structure or a multi-layer structure, and its thickness is, for example, 10 nm to 100 nm. When the electronic functional layer 1035 is a multi-layer structure, it may include one or more of an electron injection layer, an electron transport layer, and a hole blocking layer. For an electronic functional layer 1035 including an electron injection layer, an electron transport layer, and a hole blocking layer, the electron transport layer is located between the electron injection layer and the hole blocking layer, and the electron injection layer is closer to the cathode 102 than the hole blocking layer. For an electronic functional layer 1035 including an electron transport layer and a hole blocking layer, the electron transport layer is closer to the cathode 102 than the hole blocking layer. For an electronic functional layer 1035 including an electron injection layer and an electron transport layer, the electron injection layer is closer to the cathode 102 than the electron transport layer.

[0073] The material of the electronic functional layer 1035 includes an undoped third metal oxide and / or a doped fourth metal oxide. The undoped third metal oxide is selected from one or more of ZnO, TiO2, SnO2, BaO, Ta2O3, Al2O3, and ZrO2; and / or, the doped fourth metal oxide is a host metal oxide doped with a second doping element, the host metal oxide being selected from ZnO, TiO2, SnO2, BaO, Ta2O3, Al2O3, or ZrO2, and the second doping element being selected from one or more of Mg, Ca, Zr, W, Ga, Li, Al, Ti, Y, In, and Sn. The doped fourth metal oxide may be, for example, Zn. (1-x) Mg x O, Zn (1-x) Ca x O, Zn (1-x) Zr x O, Zn (1-x) Ga x O, Zn (1-x) Al x O, Zn (1-x) Li x O, Al (1-x) Zn x O, Zn (1-x) Ti x O, Zn (1-x) Y x O、In (1-x) Sn x O and Ti (1-x) Li x One or more of O, where 0 < x ≤ 0.5.

[0074] This application also provides a method for fabricating an optoelectronic device, which can be used to fabricate any of the optoelectronic devices described above. The method for fabricating the optoelectronic device includes the following steps:

[0075] S1. Provide a bottom electrode and form a functional layer on one side of the bottom electrode;

[0076] S2. A top electrode is formed on the side of the functional layer away from the bottom electrode.

[0077] In the case of a photoelectric device with an upright structure, where the bottom electrode is the anode and the top electrode is the cathode, forming a functional layer on one side of the bottom electrode includes the steps of sequentially forming a first active layer and an auxiliary layer on one side of the bottom electrode. Alternatively, in the case of a photoelectric device with an inverted structure, where the bottom electrode is the cathode and the top electrode is the anode, forming a functional layer on one side of the bottom electrode includes the steps of sequentially forming an auxiliary layer and a first active layer on one side of the bottom electrode. The formation methods for the first active layer and the auxiliary layer can be, for example, solution processing. The structural composition of the first active layer, the auxiliary layer, the anode, and the cathode are all as described above. The first quantum dot and the nanoparticle are also as described above. The first ligand connected to the surface of the first quantum dot, the second ligand connected to the unshelled portion of the core of the nanoparticle, and the third ligand connected to the surface of the shell of the nanoparticle are all as described above.

[0078] Taking a photoelectric device with a positive orientation as an example, the step of sequentially forming a first active layer and an auxiliary layer on one side of the bottom electrode includes the following steps:

[0079] S11. A solidified film including the first quantum dots is formed on one side of the bottom electrode to obtain the first active layer;

[0080] S12. A second dispersion containing nanoparticles is deposited on the side of the first active layer away from the bottom electrode, and then the deposited second dispersion is dried to obtain an auxiliary layer.

[0081] The step of forming a cured film including the first quantum dots on one side of the bottom electrode includes, for example, the steps of: depositing a first dispersion containing the first quantum dots on one side of the bottom electrode, and then drying the deposited first dispersion to obtain a first active layer.

[0082] Taking an inverted optoelectronic device as an example, the step of sequentially forming an auxiliary layer and a first active layer on one side of the bottom electrode includes the following steps:

[0083] S11': A curing film containing nanoparticles is formed on one side of the bottom electrode to obtain an auxiliary layer;

[0084] S12' Deposit a first dispersion containing the first quantum dots on the side of the auxiliary layer away from the bottom electrode, and then dry the deposited first dispersion to obtain the first active layer.

[0085] The step of forming a cured film containing nanoparticles on one side of the bottom electrode includes, for example, the steps of: depositing a second dispersion containing nanoparticles on one side of the bottom electrode, and then drying the deposited second dispersion to obtain a cured film containing nanoparticles.

[0086] Specifically, the deposition methods of the first and second dispersions include, but are not limited to, one or more of the following: spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, strip coating, and solution electrodeposition. The concentration of the first quantum dots in the first dispersion is 5 mg / mL to 50 mg / mL, and / or the concentration of nanoparticles in the second dispersion is 1 mg / mL to 10 mg / mL. The drying treatment in steps S12 and S12' includes, but is not limited to, one or more of the following: heat treatment and vacuum drying.

[0087] The dispersion media of the first and second dispersions include, but are not limited to, one or more of alkanes, aromatic hydrocarbons, halogenated alkanes, alcohols, ethers, furans, pyridines, amides, and sulfones. Specifically, alkanes include, but are not limited to, one or more of nonane, decane, dodecane, terpenes, butylcyclohexane, n-octane, n-hexane, n-heptane, n-nonane, n-decane, cyclohexane, and cyclopentane; aromatic hydrocarbons include, but are not limited to, one or more of diethylbenzene, trimethylbenzene, propylbenzene, isopropylbenzene, p-toluene, butylbenzene, and 1-methylnaphthalene or indene; halogenated alkanes include, but are not limited to, one or more of dichloromethane, chloroform, and carbon tetrachloride; alcohols include, but are not limited to, one or more of methanol, ethanol, propanol, butanol, ethylene glycol, and glycerol; ethers include, but are not limited to, ethylene glycol monomethyl ether; furans include, but are not limited to, tetrahydrofuran; pyridines include, but are not limited to, pyridine; amides include, but are not limited to, N,N-dimethylformamide; and sulfones include, but are not limited to, dimethyl sulfoxide.

[0088] Understandably, if the original ligand of the first quantum dot is not the first ligand, it can be replaced by ligand exchange. Ligand exchange can be carried out in solution or while the first quantum dot is in a solid film. For example, the first quantum dot can be first prepared into a solid film using a solution method, and then a high concentration of the first ligand solution (concentration, for example, 60 mg / mL to 300 mg / mL) can be applied to one side of the solid film. That is, the concentration difference is used to drive ligand exchange. Then, excess first ligand solution and the displaced original ligand are washed away, and then the film is dried. Similarly, if the second and / or third ligands are not the original ligands of the nanoparticles, they can also be replaced by the target ligands through ligand exchange.

[0089] Furthermore, in some embodiments of this application, when the optoelectronic device has an upright structure, after the step of depositing the second dispersion and before the step of drying the deposited second dispersion, a preset settling time is allowed to ensure that a sufficient number of first quantum dots are connected to or close to the nanoparticles. The settling time may be, for example, 5 to 30 minutes. Similarly, when the optoelectronic device has an inverted structure, after the step of depositing the first dispersion and before the step of drying the deposited first dispersion, a preset settling time is allowed. The settling time may be, for example, 5 to 30 minutes.

[0090] To further improve the photoelectric performance and lifespan of optoelectronic devices, in some embodiments of this application, when the optoelectronic device has an upright structure, after the step of depositing the second dispersion and before the step of drying the deposited second dispersion, the step of sequentially forming the first active layer and the auxiliary layer on one side of the bottom electrode further includes: cleaning the film layer formed by depositing the second dispersion with a first solvent to remove nanoparticles not connected to the first quantum dots. When the optoelectronic device has an inverted structure, after the step of depositing the first dispersion and before the step of drying the deposited first dispersion, the step of sequentially forming the auxiliary layer and the first active layer on one side of the bottom electrode further includes: cleaning the film layer formed by depositing the first dispersion with a second solvent to remove the first quantum dots not connected to the nanoparticles. Optionally, the first solvent and the second solvent are independently selected from alkanes having 5 to 15 carbon atoms or aliphatic alcohols having 5 to 15 carbon atoms, for example, n-hexane or n-hexanol.

[0091] To further improve the photoelectric performance and device lifetime of optoelectronic devices, in some embodiments of this application, when the optoelectronic device has a normal-position structure, forming a functional layer on one side of the bottom electrode further includes the step of forming a second active layer on the side of the auxiliary layer away from the first active layer; or, when the optoelectronic device has an inverted structure, before forming the auxiliary layer and the first active layer sequentially on one side of the bottom electrode, forming a functional layer on one side of the bottom electrode further includes the step of forming a second active layer on one side of the bottom electrode, with the auxiliary layer formed on the side of the second active layer away from the bottom electrode; the material of the second active layer includes a second quantum dot. The method for forming the second active layer can be, for example, a solution method, and the structural composition of the second active layer and the second quantum dot are as described above.

[0092] To further improve the overall performance of optoelectronic devices, in some embodiments of this application, forming a functional layer on one side of the bottom electrode further includes the steps of: forming a hole functional layer between the anode and the first active layer, and / or forming an electronic functional layer between the cathode and the auxiliary layer, wherein the structural composition of the electronic functional layer and the hole functional layer is as described above. As an example, when the optoelectronic device has a positively oriented structure, forming a functional layer on one side of the bottom electrode includes the steps of: sequentially forming a hole functional layer, a first active layer, an auxiliary layer, a second active layer, and an electronic functional layer on one side of the bottom electrode, or sequentially forming a hole functional layer, a first active layer, an auxiliary layer, and an electronic functional layer on one side of the bottom electrode; when the optoelectronic device has an inverted structure, forming a functional layer on one side of the bottom electrode includes the steps of: sequentially forming an electronic functional layer, a second active layer, an auxiliary layer, a first active layer, and a hole functional layer on one side of the bottom electrode, or sequentially forming an electronic functional layer, an auxiliary layer, a first active layer, and a hole functional layer on one side of the bottom electrode.

[0093] It should be noted that, in addition to the first active layer, auxiliary layer, and second active layer, the preparation methods for other films in optoelectronic devices include, but are not limited to, chemical and / or physical methods. Chemical methods include, but are not limited to, one or more of chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, and co-precipitation. Physical methods include, but are not limited to, physical deposition and solution methods. Physical deposition methods include, but are not limited to, one or more of thermal evaporation deposition, electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition, atomic layer deposition, and pulsed laser deposition. Solution methods include, but are not limited to, one or more of spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating. After the various films of the optoelectronic device are prepared, an encapsulation process is required. Encapsulation can be performed using common machine encapsulation or manual encapsulation. In the encapsulation environment, the oxygen and water content are both below 0.1 ppm to ensure the stability of the optoelectronic device.

[0094] This application also provides an electronic device, which includes any of the optoelectronic devices described above, or optoelectronic devices prepared by any of the methods described above. The electronic device can be, for example, any electronic product with a display function, including but not limited to smartphones, tablet personal computers, mobile phones, video phones, e-book readers, laptop PCs, netbook computers, workstations, servers, personal digital assistants, portable multimedia players, MP3 players, mobile medical devices, cameras, game consoles, digital cameras, car navigation systems, electronic billboards, ATMs, smart bracelets, smartwatches, virtual reality (VR) devices, or wearable devices.

[0095] The technical solutions and effects of this application will be described in detail below through specific embodiments, comparative examples and experimental examples. The following embodiments are only some embodiments of this application and are not intended to limit this application.

[0096] Example 1

[0097] This embodiment provides an optoelectronic device and its fabrication method. The optoelectronic device is a quantum dot light-emitting diode with a positive-position structure, such as... Figure 2 As shown, in the top-down direction, the optoelectronic device 10 includes an anode 101, a functional layer 103, and a cathode 102 stacked sequentially. The functional layer 103 includes a hole functional layer 1034, a first active layer 1031, an auxiliary layer 1032, a second active layer 1033, and an electronic functional layer 1035 stacked sequentially. The electronic functional layer 1035 is closer to the cathode 102 than the hole functional layer 1034. The hole functional layer 1034 is composed of a hole injection layer 10341 and a hole transport layer 10342 stacked sequentially, with the hole injection layer 10341 closer to the anode 101 than the hole transport layer 10342. The light-emitting area is 0.04 cm². 2 .

[0098] The structural composition of each layer in optoelectronic device 10 is as follows:

[0099] The substrate is made of glass and has an average thickness of 2 mm.

[0100] The anode 101 is made of ITO and has an average thickness of 50 nm.

[0101] The cathode 102 is made of Ag and has an average thickness of 80 nm.

[0102] The material of the first active layer 1031 is a first quantum dot (CdS quantum dot, emitting blue light, with an average particle size of 10 nm), the average thickness of the first active layer 1031 is 10 nm, and a second ligand, ethylene glycol, is attached to the surface of the first quantum dot.

[0103] The auxiliary layer 1032 is made of ZnO / SiO2 nanoparticles with a core-shell structure. The core is made of ZnO and the shell is made of SiO2. The shell partially covers the core. The unshell-covered part of the core is connected to the first quantum dot in the first active layer 1031 through a second ligand. The surface of the shell is connected to a third ligand (n-octylamine). There is no connection between the shell and the first quantum dot. For the core, the unshell-covered part is closer to the first active layer 1031 than the shell-covered part. The ZnO / SiO2 nanoparticles in the auxiliary layer 1032 are arranged in a single layer.

[0104] The material of the second active layer 1033 is a second quantum dot (CdS quantum dot, emitting blue light, with an average particle size of 10 nm). The average thickness of the second active layer 1033 is 20 nm. The surface of the second quantum dot is connected to a fourth ligand, which is oleic acid (CAS number 112-80-1).

[0105] The electronic functional layer 1035 is made of nano-ZnO, and the average thickness of the electronic functional layer 1035 is 50 nm.

[0106] The hole injection layer 10341 is made of PEDOT:PSS and has an average thickness of 40 nm.

[0107] The hole transport layer 10342 is made of TFB material and has an average thickness of 30 nm.

[0108] The preparation method of nano-ZnO includes the following steps:

[0109] S10. Mix 5.5g of zinc acetate dihydrate and 150mL of ethanol, and stir at 80℃ to completely dissolve the zinc acetate dihydrate to obtain a mixture.

[0110] S20. Place the mixture in a water bath at 0°C, slowly add 20 mL of a 1.75 mol / L potassium hydroxide aqueous solution to the mixture, and stir until clear to obtain a uniform and transparent solution.

[0111] S30. Add heptane to the solution obtained in step S20 to form a precipitate. The volume ratio of the solution to heptane is 3:1. Then centrifuge and collect the precipitate. Dissolve the precipitate in methanol again and add heptane again. Centrifuge and collect the precipitate again. Repeat this process twice. The final precipitate is nano ZnO. Dissolve the nano ZnO in ethanol to obtain a nano ZnO-ethanol solution with a concentration of 30 mg / mL for later use.

[0112] The preparation method of ZnO / SiO2 nanoparticles includes the following steps:

[0113] S100. Weigh 5.5g of zinc acetate dihydrate and dissolve it in 150mL of ethanol. Heat and stir at 80℃ until the zinc acetate dihydrate is completely dissolved to obtain a mixture. Then place the mixture in a 4℃ cold water bath and slowly add 20mL of 1.75mol / L potassium hydroxide aqueous solution to it. Stir until the solution becomes clear to obtain a solution containing ZnO nanoparticles.

[0114] S200: Mix 400 μL of silane coupling agent solution with 2 mL of deionized water to obtain a mixture, wherein the solute of the silane coupling agent solution is APTES (CAS No. 919-30-2), the solvent of the silane coupling agent solution is isopropanol, and the concentration of APTES in the silane coupling agent solution is 0.4 mol / L; then, add the mixture dropwise to the solution containing ZnO nanoparticles obtained in step S100 to obtain a first mixed system; next, centrifuge the first mixed system at 6000 r / min for 2 min, collect the precipitate, wash the collected precipitate several times with ethanol, and finally disperse it in deionized water to obtain an aqueous solution of ZnO nanoparticles fully coated with SiO2;

[0115] S300. Take 50 mL of chlorobenzene as the oil phase solution and place it in a 200 mL beaker. Then, slowly add 20 mL of an aqueous phase solution of ZnO nanoparticles fully coated with SiO2 to the chlorobenzene to form an aqueous-oil phase interface. Let it stand for 2 hours. After a stable interface is formed, add 1 mL of 95% (volume percentage) ethanol aqueous solution to the aqueous phase to allow a small amount of ZnO nanoparticles fully coated with SiO2 to precipitate and float on the surface of the chlorobenzene, thus obtaining a second mixed system.

[0116] S400. Add 5 mL of n-octylamine to the oil phase of the second mixture system and react for 10 min to bind it to the lower half of the ZnO nanoparticles fully coated with SiO2 at the interface to obtain the third mixture system.

[0117] S500. Add 4 mL of hydrogen peroxide and 1 mL of hydrofluoric acid to the aqueous phase of the third mixing system and react for 30 min to etch away the SiO2 in the upper half of the ZnO nanoparticles that are fully coated with SiO2 at the interface. Then remove the aqueous phase and add 10 mL of n-hexane to the oil phase. Separate the solid and liquid phases to obtain a precipitate, which is the ZnO / SiO2 nanoparticles. Disperse the ZnO / SiO2 nanoparticles in n-hexanol to obtain a nanoparticle solution for later use.

[0118] The method for fabricating the optoelectronic device in this embodiment includes the following steps:

[0119] S1.1 Provide a substrate, sputter ITO on one side of the substrate to obtain an ITO layer, wipe the surface of the ITO layer with a small amount of soapy water using a cotton swab to remove visible impurities, and then sequentially ultrasonically clean the substrate containing ITO with deionized water for 15 min, acetone for 15 min, ethanol for 15 min, and isopropanol for 15 min. After drying, perform ultraviolet-ozone surface treatment for 20 min to obtain a substrate containing an anode.

[0120] S1.2 Under normal temperature and pressure air environment, spin-coat a 2.8% PEDOT:PSS aqueous solution on the side of the anode away from the substrate, and then place it under constant temperature heat treatment at 150℃ to solidify into a film to obtain a hole injection layer.

[0121] S1.3 Under normal temperature and pressure nitrogen atmosphere, spin-coat a TFB-chlorobenzene solution with a concentration of 8 mg / mL on the side of the hole injection layer away from the anode, and then place it under constant temperature heat treatment at 150℃ in nitrogen atmosphere to solidify into a film to obtain the hole transport layer.

[0122] S1.4 Under normal temperature and pressure nitrogen atmosphere, spin-coat a first quantum dot-n-octane solution with a concentration of 10 mg / mL on the side of the hole transport layer away from the hole injection layer, and then place it under constant temperature heat treatment at 100℃ in nitrogen atmosphere to solidify into a film to obtain the first active layer.

[0123] S1.5 Under normal temperature and pressure nitrogen atmosphere, drop a 10 mg / mL nanoparticle ZnO / SiO2-n-hexanol solution onto the side of the first active layer away from the hole transport layer until it completely covers the side of the first active layer away from the hole transport layer. Then, wash with n-hexane several times to remove nanoparticle ZnO / SiO2 that are not connected to the first quantum dot. Then, place it under constant temperature heat treatment at 100℃ in nitrogen atmosphere to solidify it into a film and obtain the auxiliary layer.

[0124] S1.6 Under normal temperature and pressure nitrogen atmosphere, spin-coat a second quantum dot-n-octane solution with a concentration of 20 mg / mL on the side of the auxiliary layer away from the first active layer, and then place it under constant temperature heat treatment at 100℃ in nitrogen atmosphere to solidify into a film to obtain the second active layer;

[0125] S1.7 Under normal temperature and pressure nitrogen atmosphere, spin-coat a nano ZnO-ethanol solution with a concentration of 30 mg / mL on the side of the second active layer away from the auxiliary layer, and then place it under constant temperature heat treatment at 80℃ in nitrogen atmosphere to solidify into a film to obtain an electronic functional sublayer.

[0126] S1.8. Place the laminated structure that has completed step S1.7 in a vacuum with a vacuum level not exceeding 3 × 10⁻⁶. -4 In the vapor deposition chamber of Pa, Ag is thermally vaporized on the side of the electronic functional layer away from the second active layer through a mask to obtain a cathode, which is then packaged to obtain an optoelectronic device.

[0127] Example 2

[0128] This embodiment provides an optoelectronic device and its fabrication method. Compared with the optoelectronic device in Embodiment 1, the difference in this embodiment is that the material of the electronic functional layer is replaced with "nano Zn". 0.9 Mg 0.1 "O", where, compared to the preparation method of nano-ZnO in Example 1, nano-Zn 0.9 Mg 0.1 The difference in the preparation method of O is that step S10 is replaced by "mixing 5.5g of zinc acetate dihydrate, 0.29g of magnesium acetate tetrahydrate and 150mL of ethanol, and stirring at 80°C to completely dissolve the zinc acetate dihydrate to obtain a mixture".

[0129] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0130] Example 3

[0131] This embodiment provides an optoelectronic device and its fabrication method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the average thickness of the second active layer is replaced with "10nm".

[0132] Compared with the method for preparing the optoelectronic device in Example 1, the method for preparing the optoelectronic device in this example differs in that: in step S1.6, "spin-coating a second quantum dot-n-octane solution with a concentration of 20 mg / mL on the side of the auxiliary layer away from the first active layer" is replaced with "spin-coating a second quantum dot-n-octane solution with a concentration of 10 mg / mL on the side of the auxiliary layer away from the first active layer".

[0133] Example 4

[0134] This embodiment provides an optoelectronic device and its fabrication method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the average thickness of the second active layer is replaced with "30nm".

[0135] Compared with the method for preparing the optoelectronic device in Example 1, the method for preparing the optoelectronic device in this example differs in that: in step S1.6, "spin-coating a second quantum dot-n-octane solution with a concentration of 20 mg / mL on the side of the auxiliary layer away from the first active layer" is replaced with "spin-coating a second quantum dot-n-octane solution with a concentration of 30 mg / mL on the side of the auxiliary layer away from the first active layer".

[0136] Example 5

[0137] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the fourth ligand is replaced with "dodecenoic acid (CAS No. 32466-54-9)".

[0138] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0139] Example 6

[0140] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the fourth ligand is replaced with "octenic acid (CAS number 1577-19-1)".

[0141] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0142] Example 7

[0143] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the fourth ligand is replaced with "hexenoic acid (CAS No. 4219-24-3)".

[0144] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0145] Example 8

[0146] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the second ligand is replaced with a "chloride ion ligand".

[0147] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0148] Example 9

[0149] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the second ligand is replaced with "1,3-propanediamine".

[0150] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0151] Example 10

[0152] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that the second ligand is replaced with "1,5-pentanediol".

[0153] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0154] Example 11

[0155] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Embodiment 1, the difference of the optoelectronic device in this embodiment is that: for the nanoparticle ZnO / SiO2, the surface of the unshell-covered part of the core is connected with a first ligand (ethylene glycol). Compared to the preparation method of ZnO / SiO2 nanoparticles in Example 1, the difference in the preparation method of ZnO / SiO2 nanoparticles in this example is only that: step S500 is replaced by "adding 4 mL of hydrogen peroxide and 1 mL of hydrofluoric acid to the aqueous phase of the third mixing system, reacting for 30 min, so that the SiO2 in the upper half of the ZnO nanoparticles fully coated at the interface is etched and removed in the aqueous phase, then injecting ethylene glycol (the volume of ethylene glycol is 2% of the volume of the aqueous phase) into the aqueous phase, letting it stand for 30 min, removing the aqueous phase, then adding 10 mL of n-hexane to the oil phase, separating the solid and liquid phases to obtain a precipitate, which is the ZnO / SiO2 nanoparticles, and dispersing the ZnO / SiO2 nanoparticles in n-hexane to obtain a nanoparticle solution for later use."

[0156] The method for preparing the optoelectronic device in this embodiment is the same as that for preparing the optoelectronic device in Example 1.

[0157] Example 12

[0158] This embodiment provides an optoelectronic device and its preparation method. Compared with the optoelectronic device in Example 1, the difference of the optoelectronic device in this embodiment is that the third ligand is replaced with "octyldiamine (CAS No. 373-44-4)".

[0159] Compared to the method for preparing the optoelectronic device in Example 1, the method for preparing the optoelectronic device in this example differs in that step S1.5 is replaced by "in a nitrogen atmosphere at room temperature and pressure, a 10 mg / mL solution of nanoparticles ZnO / SiO2-n-hexanol is dropped onto the side of the first active layer away from the hole transport layer until it completely covers the side of the first active layer away from the hole transport layer. Then, the solution is washed several times with n-hexane to remove the nanoparticles ZnO / SiO2 that are not connected to the first quantum dot. Then, the solution is placed in a nitrogen atmosphere at 100°C for constant temperature heat treatment to form a cured film. Then, octanediamine is spin-coated onto the side of the cured film away from the hole transport layer. After standing for 30 minutes, the side of the cured film away from the hole transport layer is washed several times with octanediamine. Finally, the solution is dried to obtain the auxiliary layer."

[0160] Example 13

[0161] This embodiment provides an optoelectronic device and its fabrication method. Compared with the optoelectronic device in Embodiment 1, the difference in this embodiment is that the second active layer is omitted, and the average thickness of the first active layer is replaced with "30nm". That is, the optoelectronic device has the following characteristics: Figure 1 The structure shown.

[0162] Compared with the method for preparing the optoelectronic device in Example 1, the method for preparing the optoelectronic device in this example differs in that: step S1.6 is omitted, and the step S1.7 of "spin-coating a nano ZnO-ethanol solution with a concentration of 30 mg / mL on the side of the second active layer away from the auxiliary layer" is replaced with "spin-coating a nano ZnO-ethanol solution with a concentration of 30 mg / mL on the side of the auxiliary layer away from the first active layer".

[0163] Comparative Example 1

[0164] This comparative example provides an optoelectronic device and its fabrication method. Compared with the optoelectronic device in Example 1, the difference in the optoelectronic device in this comparative example is that the auxiliary layer and the second active layer are omitted, and the average thickness of the first active layer is replaced with "30nm".

[0165] Compared with the method for preparing the optoelectronic device in Example 1, the method for preparing the optoelectronic device in this comparative example differs in that steps S1.5 and S1.6 are omitted, and the step S1.7 of "spin-coating a nano ZnO-ethanol solution with a concentration of 30 mg / mL on the side of the second active layer away from the auxiliary layer" is replaced with "spin-coating a nano ZnO-ethanol solution with a concentration of 30 mg / mL on the side of the first active layer away from the hole transport layer".

[0166] Comparative Example 2

[0167] This comparative example provides an optoelectronic device and its fabrication method. Compared with the optoelectronic device in Example 1, the difference in the optoelectronic device in this comparative example is that the auxiliary layer and the first active layer are omitted, and the average thickness of the second active layer is replaced with "30nm".

[0168] Compared to the method for preparing the optoelectronic device in Example 1, the method for preparing the optoelectronic device in this comparative example differs in that: step S1.4 is replaced with "in a nitrogen atmosphere at room temperature and pressure, a second quantum dot-n-octane solution with a concentration of 30 mg / mL is spin-coated on the side of the hole transport layer away from the hole injection layer, and then placed in a constant temperature heat treatment at 100°C in a nitrogen atmosphere to solidify and form a film, thereby obtaining the second active layer", and steps S1.5 and S1.6 are omitted, and in step S1.7, "a nano ZnO-ethanol solution with a concentration of 30 mg / mL is spin-coated on the side of the second active layer away from the auxiliary layer" is replaced with "a nano ZnO-ethanol solution with a concentration of 30 mg / mL is spin-coated on the side of the second active layer away from the hole transport layer".

[0169] Experimental Example

[0170] The performance of the optoelectronic devices in Examples 1 to 13, Comparative Examples 1 and 2 after 1 hour of encapsulation was tested. The performance tests were conducted at a temperature of 25°C and a relative humidity of 40%.

[0171] The photoelectric performance was tested using a Fostar FPD optical property measurement system (comprising a Marine Optics USB2000, a LabVIEW-controlled QE-PRO spectrometer, a Keithley 2400, a high-precision digital source meter Keithley 6485, a 50μm inner diameter optical fiber, device test probes and fixtures, various connecting cables and data cards, an efficiency test cassette, and a data acquisition system). The system acquired parameters such as the turn-on voltage, current, brightness, and emission spectrum of each photoelectric device, and then calculated the maximum external quantum efficiency (EQE). max Key parameters include (%), power efficiency, etc.

[0172] The device lifetime testing method includes the following steps: under constant current (2mA) driving, electroluminescence lifetime analysis is performed on each optoelectronic device using lifetime testing equipment, the time required for each optoelectronic device to decay from maximum brightness to 95% (T95,h) is recorded, and the time required for each optoelectronic device to decay from 100% brightness to 95% brightness at 1000nit brightness (T95@1000nit,h) is calculated by using the decay fitting formula.

[0173] The performance test data for each optoelectronic device are detailed in Table 1 below:

[0174] Table 1

[0175]

[0176]

[0177] As shown in Table 1, compared to the overall performance of the optoelectronic devices in Comparative Examples 1 and 2, the optoelectronic devices in Examples 1 to 13 exhibit superior overall performance. Specifically, the optoelectronic devices in Examples 1 to 13 have higher luminous efficiency, longer device lifetime, and better performance stability. Taking the optoelectronic devices in Example 2 and Comparative Example 1 as examples, the EQE of the optoelectronic device in Example 2... max EQE of the optoelectronic device in Comparative Example 1 max The T95@1000nit of the optoelectronic device in Example 2 is 1.8 times that of the T95@1000nit of the optoelectronic device in Example 1, and is 4.9 times that of the T95@1000nit of the optoelectronic device in Example 1.

[0178] Therefore, introducing an auxiliary layer between the first active layer and the cathode can block some electrons from being injected into the first active layer and slow down the rate of electron injection into the first active layer, thereby reducing the electron injection level, promoting electron-hole transport balance, and thus improving the device lifetime of the optoelectronic device. Further introducing a second active layer between the auxiliary layer and the cathode is beneficial for further improving the device efficiency and device lifetime of the optoelectronic device. Since the optoelectronic devices in Comparative Examples 1 and 2 do not have an auxiliary layer, the matching degree between the electron injection level and the hole injection level in the optoelectronic devices in Comparative Examples 1 and 2 is low, resulting in lower device efficiency and device lifetime.

[0179] The foregoing has provided a detailed description of an optoelectronic device and its fabrication method according to the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An optoelectronic device, characterized in that, The optoelectronic device includes: The anode and cathode are arranged opposite each other; and A functional layer is disposed between the anode and the cathode; The functional layer includes a first active layer and an auxiliary layer stacked together. The auxiliary layer is closer to the cathode than the first active layer. The material of the first active layer includes a first quantum dot. The material of the auxiliary layer includes nanoparticles with a core-shell structure. The core of the nanoparticles is a first metal oxide.

2. The optoelectronic device according to claim 1, characterized in that, The nanoparticles in the auxiliary layer are arranged in a single layer; and / or The first quantum dot is selected from one or more of single-component luminescent quantum dots, core-shell luminescent quantum dots, inorganic perovskite luminescent quantum dots, organic perovskite luminescent quantum dots, and organic-inorganic hybrid perovskite luminescent quantum dots, wherein the shell of the core-shell luminescent quantum dot has one or more layers; and / or The first quantum dots in the first active layer are arranged in a single layer; and / or The average particle size of the first quantum dot is 2 nm to 20 nm; and / or The average thickness of the first active layer is 8 nm to 60 nm; and / or The average thickness of the auxiliary layer is 3 nm to 10 nm; and / or The functional layer further includes a hole functional layer, which is disposed between the auxiliary layer and the anode; Optionally, the hole functional layer includes a hole injection layer and / or a hole transport layer. When the hole functional layer includes a stacked hole injection layer and a hole transport layer, the hole injection layer is closer to the anode than the hole transport layer. And / or, the energy layer further includes an electronic functional layer disposed between the first active layer and the cathode; Optionally, the electronic functional layer includes an electron injection layer and / or an electron transport layer. When the electronic functional layer includes an electron injection layer and an electron transport layer stacked together, the electron injection layer is closer to the cathode than the electron transport layer.

3. The optoelectronic device according to claim 1, characterized in that, The shell portion of the nanoparticle encapsulates the core of the nanoparticle; and / or The shell material of the nanoparticles is an insulating compound; optionally, the insulating compound is selected from one or more of silicon oxides and silicon nitrides; and / or The first metal oxide is selected from one or more of the following: zinc oxide, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, chromium oxide, and copper oxide; and / or The average particle size of the nanoparticles is 3 nm to 10 nm, and / or the mass of the shell of the nanoparticles accounts for 5% to 15% of the total mass of the nanoparticles; and / or The oxygen atoms in the first metal oxide are covalently bonded to the insulating compound.

4. The optoelectronic device according to claim 3, characterized in that, The shell of the nanoparticle has an average coverage rate of 30% to 70% over the core of the nanoparticle; and / or Regarding the core of the nanoparticle, the shell-covered portion of the nanoparticle is closer to the first active layer than the uncoated portion; and / or The first metal oxide is selected from one or more of ZnO, NiO, MoO3, WO3, V2O5, Cr2O3, CuO, and Cu2O; and / or The insulating compound is selected from SiO2.

5. The optoelectronic device according to claim 3, characterized in that, The surface of the first quantum dot is connected to a first ligand, and / or the portion of the core of the nanoparticle that is not covered by the shell of the nanoparticle is connected to a second ligand, and / or the surface of the shell of the nanoparticle is connected to a third ligand. Wherein, the first ligand, the second ligand, and the third ligand are each independently selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, and -NO2 groups. And one or more of the ligands of the general formula L1-L2, where X is a halogen atom and L2 is a coordinating group; L1 is selected independently each time from an unsubstituted or substituted aliphatic chain hydrocarbon group having 1 to 30 carbon atoms, an unsubstituted or substituted aliphatic chain hydrocarbon oxy group having 1 to 30 carbon atoms, an unsubstituted or substituted aliphatic cyclic hydrocarbon group having 3 to 30 ring atoms, an unsubstituted or substituted aliphatic heterocyclic hydrocarbon group having 3 to 30 ring atoms, an unsubstituted or substituted aryl group having 6 to 30 ring atoms, an unsubstituted or substituted aryloxy group having 6 to 30 ring atoms, an unsubstituted or substituted aryloxy group having 6 to 30 ring atoms, an unsubstituted or substituted heteroaryl group having 5 to 30 ring atoms, or an unsubstituted or substituted heteroaryloxy group having 5 to 30 ring atoms, or a combination of these groups. Each occurrence of the first group is independently selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, -NO2. Or combinations of these groups; R1 to R7 are each independently selected from an aliphatic chain hydrocarbon group having 1 to 10 carbon atoms, an aliphatic chain hydrocarbon oxy group having 1 to 10 carbon atoms, an aliphatic cyclic hydrocarbon group having 3 to 10 ring atoms, an aliphatic heterocyclic hydrocarbon group having 3 to 10 ring atoms, an aryl group having 6 to 14 ring atoms, an aryloxy group having 6 to 14 ring atoms, a heteroaryl group having 5 to 14 ring atoms, or a heteroaryloxy group having 5 to 14 ring atoms, or combinations of these groups; L2 is selected independently from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, and -NO2 groups each time it appears. Or a combination of these groups.

6. The optoelectronic device according to claim 5, characterized in that, The first ligand includes a coordination terminal and a free terminal. The coordination terminal of the first ligand is connected to the surface of the first quantum dot, and the free terminal of the first ligand has a first electrical charge. The second ligand includes a coordination terminal and a free terminal. The coordination terminal of the second ligand is connected to the portion of the core of the nanoparticle that is not enclosed by the shell of the nanoparticle, and the free terminal of the second ligand has a second electrical charge. One of the first and second electrical charges is positively charged, and the other is negatively charged; and / or The first quantum dot is connected to the portion of the core of the nanoparticle that is not encased in the shell of the nanoparticle via the first ligand and / or the second ligand.

7. The optoelectronic device according to claim 6, characterized in that, The third ligand includes a coordination terminal and a free terminal. The coordination terminal of the third ligand is connected to the shell of the nanoparticle, and the free terminal of the third ligand is electrically neutral or has a third electrical property, wherein the first electrical property is the same as the third electrical property; and / or The first ligand and the third ligand are each independently selected from electron-withdrawing groups or ligands of the general formula L1-L2, and the second ligand is selected from electron-donating groups or ligands of the general formula L1-L2; in the first ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, and each occurrence of the first group is independently selected from an electron-withdrawing group; in the third ligand, L1 is selected from an aliphatic chain hydrocarbon group having 8 to 30 carbon atoms substituted by at least one first group, and each occurrence of the first group is independently selected from an electron-withdrawing group; in the second ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, and each occurrence of the first group is independently selected from an electron-donating group; Alternatively, the first ligand and the third ligand are each independently selected from electron-donating groups or ligands of the general formula L1-L2, and the second ligand is selected from electron-withdrawing groups or ligands of the general formula L1-L2; in the first ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, and each occurrence of the first group is independently selected from an electron-donating group; in the third ligand, L1 is selected from an aliphatic chain hydrocarbon group having 8 to 30 carbon atoms substituted by at least one first group, and each occurrence of the first group is independently selected from an electron-donating group; in the second ligand, L1 is selected from an aliphatic chain hydrocarbon group having 1 to 6 carbon atoms substituted by at least one first group, and each occurrence of the first group is independently selected from an electron-withdrawing group.

8. The optoelectronic device according to claim 7, characterized in that, The first ligand and the third ligand are each independently selected from a carboxyl group, -NO2, an aldehyde group, or ligands of the general formula L1-L2. The second ligand is selected from a hydroxyl group, -OCH3, or ligands of the general formula L1-L2. In the first ligand and the third ligand, each occurrence of the first group is independently selected from a carboxyl group, -NO2, or an aldehyde group, and each occurrence of L2 is independently selected from a carboxyl group, -NO2, or an aldehyde group. Similarly, in the second ligand, each occurrence of the first group is independently selected from a hydroxyl group or -OCH3, and each occurrence of L2 is selected from a hydroxyl group or -OCH3. Alternatively, the first ligand and the third ligand are each independently selected from hydroxyl, -OCH3, or ligands of the general formula L1-L2, the second ligand is selected from hydroxyl, -OCH3, or ligands of the general formula L1-L2, and in the first ligand and the third ligand, the first group is independently selected from hydroxyl or -OCH3 each time it appears, and L2 is independently selected from hydroxyl or -OCH3 each time it appears, and in the second ligand, the first group is independently selected from carboxyl, -NO2, or aldehyde each time it appears, and L2 is selected from carboxyl, -NO2, or aldehyde.

9. The optoelectronic device according to any one of claims 1 to 8, characterized in that, The functional layer further includes a second active layer, which is disposed between the auxiliary layer and the cathode; The material of the second active layer includes a second quantum dot, which is selected from one or more of single-component luminescent quantum dots, core-shell structured luminescent quantum dots, inorganic perovskite luminescent quantum dots, organic perovskite luminescent quantum dots, and organic-inorganic hybrid perovskite luminescent quantum dots. The shell of the core-shell structured luminescent quantum dot is one or more layers.

10. The optoelectronic device according to claim 9, characterized in that, The average particle size of the second quantum dot is 2 nm to 20 nm; and / or The thickness ratio of the first active layer to the second active layer is 1:(1-5); and / or The average thickness of the first active layer is 8 nm to 15 nm, and / or the average thickness of the second active layer is 8 nm to 45 nm; and / or The surface of the second quantum dot is attached with a fourth ligand, which is selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, -NO2, etc. Or ligands of the general formula L1-L2; L1 is selected from unsubstituted or substituted aliphatic chain hydrocarbons having 8 to 30 carbon atoms, and L2 is a coordinating group; L2 and the first group are independently selected from hydroxyl, carboxyl, mercapto, aldehyde, -NR1R2, -O-R7, -X, and -NO2, respectively. R1 through R7 are each independently selected from aliphatic chain hydrocarbon groups having 1 to 10 carbon atoms; and / or At least a portion of the second quantum dot is connected to the shell of the nanoparticle.

11. A method for fabricating an optoelectronic device, characterized in that, Includes the following steps: Provide a bottom electrode, and form a functional layer on one side of the bottom electrode; and A top electrode is formed on the side of the functional layer away from the bottom electrode; Wherein, when the optoelectronic device is a positively oriented structure, the bottom electrode is the anode and the top electrode is the cathode, and the step of forming a functional layer on one side of the bottom electrode includes the steps of: sequentially forming a first active layer and an auxiliary layer on one side of the bottom electrode; or, when the optoelectronic device is an inverted structure, the bottom electrode is the cathode and the top electrode is the anode, and the step of forming a functional layer on one side of the bottom electrode includes the steps of: sequentially forming an auxiliary layer and a first active layer on one side of the bottom electrode; The material of the first active layer includes a first quantum dot; the material of the auxiliary layer includes nanoparticles with a core-shell structure, wherein the core of the nanoparticles is a first metal oxide.

12. The preparation method according to claim 11, characterized in that, The material of the auxiliary layer is selected from the nanoparticles described in claim 3 or 4; and / or The first quantum dot is selected from one or more of single-component luminescent quantum dots, core-shell luminescent quantum dots, inorganic perovskite luminescent quantum dots, organic perovskite luminescent quantum dots, and organic-inorganic hybrid perovskite luminescent quantum dots, wherein the shell of the core-shell luminescent quantum dot of the nanoparticle has one or more layers; and / or The step of forming a functional layer on one side of the bottom electrode further includes: forming a hole functional layer between the first active layer and the anode; and / or The step of forming a functional layer on one side of the bottom electrode further includes: forming an electronic functional layer between the auxiliary layer and the cathode; and / or The step of forming a functional layer on one side of the bottom electrode further includes the step of forming a second active layer between the auxiliary layer and the cathode. The material of the second active layer includes a second quantum dot. The second quantum dot is selected from one or more of single-component luminescent quantum dots, core-shell structured luminescent quantum dots, inorganic perovskite luminescent quantum dots, organic perovskite luminescent quantum dots, and organic-inorganic hybrid perovskite luminescent quantum dots. The shell of the core-shell structured luminescent quantum dot is one or more layers.

13. The preparation method according to claim 12, characterized in that, The surface of the first quantum dot is connected with a first ligand as described in any one of claims 5 to 8; and / or The portion of the core of the nanoparticle that is not enclosed by the shell of the nanoparticle is connected to a second ligand as described in any one of claims 5 to 8; and / or The surface of the shell of the nanoparticle is connected to a third ligand as described in any one of claims 5 to 8; and / or The surface of the second quantum dot is connected to the fourth ligand as described in claim 10.

14. The preparation method according to any one of claims 11 to 13, characterized in that, When the optoelectronic device is an upright structure, the step of sequentially forming a first active layer and an auxiliary layer on one side of the bottom electrode includes: forming a cured film including the first quantum dots on one side of the bottom electrode to obtain the first active layer; then depositing a second dispersion including the nanoparticles on the side of the first active layer away from the bottom electrode; and then drying the deposited second dispersion to obtain the auxiliary layer. Alternatively, when the optoelectronic device is an inverted structure, the step of sequentially forming an auxiliary layer and a first active layer on one side of the bottom electrode includes: forming a cured film containing the nanoparticles on one side of the bottom electrode to obtain the auxiliary layer; depositing a first dispersion containing the first quantum dots on the side of the auxiliary layer away from the bottom electrode; and then drying the deposited first dispersion to obtain the first active layer.

15. The preparation method according to claim 14, characterized in that, The dispersion media of the first dispersion and the second dispersion are independently selected from one or more of alkanes, aromatic hydrocarbons, haloalkanes, alcohols, ethers, furans, pyridines, and amides; and / or The concentration of the first quantum dots in the first dispersion is 5 mg / mL to 50 mg / mL; and / or The concentration of the nanoparticles in the second dispersion is 1 mg / mL to 10 mg / mL; and / or When the optoelectronic device is an upright structure, after the step of depositing the second dispersion and before the step of drying the deposited second dispersion, the step of sequentially forming the first active layer and the auxiliary layer on one side of the bottom electrode further includes: cleaning the film layer formed by depositing the second dispersion with a first solvent to remove the nanoparticles that are not connected to the first quantum dots; or, when the optoelectronic device is an inverted structure, after the step of depositing the first dispersion and before the step of drying the deposited first dispersion, the step of sequentially forming the auxiliary layer and the first active layer on one side of the bottom electrode further includes: cleaning the film layer formed by depositing the first dispersion with a second solvent to remove the first quantum dots that are not connected to the nanoparticles; Optionally, the first solvent and the second solvent are each independently selected from alkanes having 5 to 15 carbon atoms or aliphatic alcohols having 5 to 15 carbon atoms.

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