Photoelectric device, preparation method thereof and display device

Abstract

The invention discloses a photoelectric device, a preparation method thereof and a display device. The photoelectric device comprises an anode, a hole injection layer, a first interface layer, a hole transport layer and a cathode which are arranged in a stacked mode. The HOMO energy level of the first interface layer is between the HOMO energy level of the hole transport layer and the HOMO energy level of the hole injection layer. According to the technical scheme, interface energy level matching can be optimized, the hole injection efficiency can be remarkably improved, the carrier injection balance of the device can be improved, the luminous efficiency of the device can be improved, and the service life of the device can be prolonged.

Description

Technical Field

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

[0002] Optoelectronic devices are devices fabricated based on the photoelectric effect. They typically include an anode, a cathode, and one or more functional film layers located between the anode and cathode. Holes and electrons migrate within optoelectronic devices. However, in some optoelectronic devices, the hole injection capability is weaker than the electron injection capability, leading to an imbalance in carrier injection within the device. Summary of the Invention

[0003] In view of this, this application provides an optoelectronic device, a method for fabricating the same, and a display device.

[0004] The embodiments of this application are implemented as follows:

[0005] In a first aspect, embodiments of this application provide an optoelectronic device, including an anode, a hole injection layer, a first interface layer, a hole transport layer, and a cathode stacked together;

[0006] The HOMO level of the first interface layer is located between the HOMO level of the hole transport layer and the HOMO level of the hole injection layer.

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

[0008] Provide the first electrode;

[0009] A film layer sequence is provided, wherein multiple film layers are sequentially disposed on one side of the first electrode according to the film layer sequence, the multiple film layers including a hole injection layer, a first interface layer and a hole transport layer;

[0010] A second electrode is disposed on the side of the plurality of film layers opposite to the first electrode to obtain an optoelectronic device;

[0011] Wherein, the first electrode is selected from one of the anode and the cathode, and the second electrode is selected from the other of the anode and the cathode; the film layer sequence includes the hole injection layer, the first interface layer and the hole transport layer stacked sequentially in the direction from the anode to the cathode; the HOMO energy level of the first interface layer is located between the HOMO energy level of the hole transport layer and the HOMO energy level of the hole injection layer.

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

[0013] The technical solution proposed in this application, by setting a first interface layer between the hole transport layer and the hole injection layer, helps to optimize the interface energy level matching, improve the hole injection efficiency, improve the carrier injection balance of the device, and increase the luminous efficiency and lifespan of the device. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

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

[0017] Figure 3 This is a schematic diagram of the structure of an optoelectronic device provided in another embodiment of this application;

[0018] Reference numerals: Optoelectronic device 100; Anode 10; Cathode 20; Light-emitting layer 30; Hole transport layer 40; Hole injection layer 50; Electron transport layer 60; First interface layer 71; Second interface layer 72; Third interface layer 73. Detailed Implementation

[0019] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. In addition, in the description of this application, the term "including" means "including but not limited to". Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and conciseness and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within that range. For example, it should be assumed that the description of a range from 1 to 6 specifically discloses subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0020] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0021] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0022] In a first aspect, embodiments of this application propose an optoelectronic device 100, which includes, but is not limited to, organic light-emitting diodes, quantum dot light-emitting diodes, photovoltaic cells, and photodetectors, etc. Please refer to... Figure 1The optoelectronic device 100 includes an anode 10, a hole injection layer 50, a first interface layer 71, a hole transport layer 40, and a cathode 20 stacked together. The HOMO level of the first interface layer 71 is located between the HOMO level of the hole transport layer 40 and the HOMO level of the hole injection layer 50. It can be understood that the stacking order of the optoelectronic device 100 can be either the anode 10, hole injection layer 50, first interface layer 71, hole transport layer 40, and cathode 20 stacked sequentially from bottom to top, or the cathode 20, hole transport layer 40, first interface layer 71, hole injection layer 50, and anode 10 stacked sequentially from bottom to top.

[0023] The technical solution proposed in this application, by setting a first interface layer 71 between the hole transport layer 40 and the hole injection layer 50, helps to optimize the interface energy level matching and form a gradient energy level between the hole transport layer 40 and the hole injection layer 50. This results in a lower interface barrier when charge carriers migrate between the hole transport layer 40 and the hole injection layer 50, thereby reducing the interface resistance, improving the hole injection efficiency, helping to improve the balance of charge carrier injection in the device, and increasing the luminous efficiency and lifespan of the device.

[0024] In some embodiments, the HOMO energy level of the hole transport layer 40 is lower than the HOMO energy level of the first interface layer 71, and the HOMO energy level of the first interface layer 71 is lower than the HOMO energy level of the hole injection layer 50; in other words, the absolute value of the HOMO energy level of the hole transport layer 40 is greater than the absolute value of the HOMO energy level of the first interface layer 71, and the absolute value of the HOMO energy level of the first interface layer 71 is greater than the absolute value of the HOMO energy level of the hole injection layer 50. It can be understood that "HOMO energy level" in this document refers to the highest occupied molecular orbital. The value of the HOMO energy level is generally negative. The descriptions such as "less than" and "greater than" mentioned in this document for a certain HOMO energy level value refer to the magnitude relationship of the values. For example, "HOMO energy level less than -5.1 eV" means that the absolute value of the HOMO energy level is greater than 5.1 eV. Specifically, values ​​satisfying "HOMO energy level less than -5.1 eV" can be -5.2 eV, -5.3 eV, etc. The HOMO energy levels discussed in this article can be obtained by ultraviolet photoelectron spectroscopy (UPS) or electrochemical cyclic voltammetry (CV).

[0025] In some embodiments, the HOMO level of the hole transport layer 40 is less than or equal to -5.1 eV, and further, it can be -5.8 to -5.2 eV; for example, it can be -5.8 eV, -5.7 eV, -5.6 eV, -5.5 eV, -5.4 eV, -5.3 eV, -5.2 eV, and any two of the above values.

[0026] In some embodiments, the hole transport layer 40 may be a hole transport material with an absolute value of HOMO energy level greater than or equal to 5.1 eV. More specifically, it may be a hole transport material with HOMO energy levels of -5.8 to -5.2 eV, such as, but not limited to, poly[(9,9'-dioctylfluorenyl-2,7-diyl)-CO-(4,4'-(N-(p-butylphenyl))diphenylamine)] (TFB, CAS: 223569-31-1, HOMO energy level -5.3 eV) and poly[bis(4-phenyl)(4-butylphenyl)amine] (Poly-TPD, CAS: 472960-35-3, HOMO energy level -5.2 eV). The following are one or more of the following: 4,4'-bis(9H-carbazole-9-yl)biphenyl (CBP, CAS: 58328-31-7, HOMO level -5.8ev), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB, CAS: 123847-85-8, HOMO level -5.5ev), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA, CAS: 139092-78-7, HOMO level -5.7ev), and poly(9-ethylenecarbazole) (PVK, CAS: 25067-59-8, HOMO level -5.8ev).

[0027] In some embodiments, the thickness of the hole transport layer 40 is 30–50 nm; for example, it can be 30 nm, 32 nm, 35 nm, 40 nm, 43 nm, 45 nm, 47 nm, 50 nm, or any range between two of the above values. It is understood that the thickness of the film layer mentioned herein can be obtained by detecting a step tester.

[0028] In some embodiments, the HOMO energy level of the hole injection layer 50 is greater than or equal to -5.4 eV. Further, the HOMO energy level can be -5.3 to -5.1 eV, for example, -5.3 eV, -5.25 eV, -5.2 eV, -5.15 eV, -5.1 eV, and any two of the above values.

[0029] In some embodiments, the hole injection layer 50 is made of a hole injection material with an absolute value of HOMO energy level less than or equal to 5.4 eV. Further, a hole injection material with HOMO energy level of -5.3 to -5.1 eV can be used, such as including but not limited to PEDOT:PSS, which has a HOMO energy level of -5.2 eV.

[0030] In some embodiments, the thickness of the hole injection layer 50 is 30 to 50 nm; for example, it can be 30 nm, 32 nm, 35 nm, 40 nm, 43 nm, 45 nm, 47 nm, 50 nm, or any two of the above values.

[0031] In some embodiments, the HOMO energy level of the first interface layer 71 is in the range of -5.1 eV to -5.4 eV. For example, the energy level can be selected from -5.1 eV, -5.15 eV, -5.2 eV, -5.25 eV, -5.3 eV, -5.35 eV, -5.4 eV, and any two of the above values; further, the HOMO energy level can be in the range of -5.36 eV to -5.21 eV. Thus, the HOMO energy level of the first interface layer 71 can be located between the hole transport layer 40 and the hole injection layer 50, which helps to build an energy level gradient and reduce the interface barrier. Based on this, the material of the first interface layer 71 can be a material with a HOMO energy level of -5.4 to -5.1 eV, and further, a material with a HOMO energy level of -5.36 to -5.21 eV. For example, the material of the first interface layer 71 can be any one of organic small molecule materials, polymer materials, and inorganic materials, including but not limited to.

[0032] The organic small molecule materials include, but are not limited to, one or more of aromatic amine compounds, triphenylamine compounds, and carbazole compounds. The aromatic amine compounds may include one or more of N,N'-diaryl-N,N'-diphenylaniline (NPD, HOMO level -5.21 eV) and N,N,N',N'-tetraphenylbenzidine (TPB, CAS: 15546-43-7, HOMO level -5.22 eV). The triphenylamine compounds may include 4- Bromotriphenylamine (CAS: 36809-26-4, HOMO level -5.34 eV), wherein the carbazole compound may include one or more of 3,6-diphenylcarbazole (CAS: 56525-79-2, HOMO level -5.36 eV), N-methylcarbazole (CAS: 1484-12-4, HOMO level -5.33 eV), and 9-ethyl-3-carbazole carboxylic acid (CAS: 57102-98-4, HOMO level -5.29 eV).

[0033] The polymer material includes one or more of polyaniline (HOMO level -5.22 eV), polyamide (HOMO level -5.36 eV), polysiloxane (HOMO level -5.26 eV), and polystyrene (HOMO level -5.31 eV).

[0034] The inorganic material comprises one or more of metal oxides and transition metal complexes. The metal oxides include one or more of molybdenum oxide (HOMO level -5.3 eV) and vanadium oxide (HOMO level -5.33 eV). The transition metal complexes include Fe(CO)5 (HOMO level -5.23 eV) and [Co(CN)6]. 3- (HOMO level is -5.3 eV), [Fe(PO4)2] 3- One or more of the following (HOMO level is -5.26 eV).

[0035] The aforementioned organic small molecule materials, polymers, and inorganic materials are all commercially available.

[0036] In some embodiments, the thickness of the first interface layer 71 can be 5–10 nm; for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any two of the above values. Controlling the first interface layer 71 within this range helps ensure that the carrier transport efficiency is within a suitable range. The thickness mentioned herein can be detected using a step tester.

[0037] Please see Figure 2 In some embodiments, the optoelectronic device 100 further includes a second interface layer 72, which is disposed between the first interface layer 71 and the hole injection layer 50. The interface stress between the second interface layer 72 and the hole injection layer 50 or between the second interface layer 72 and the first interface layer 71 is 2 to 6 Pa; for example, it can be 2 Pa, 3 Pa, 4 Pa, 5 Pa, 6 Pa, or any two of the above values. After setting the second interface layer 72, it helps to reduce the interface stress between the first interface layer 71 and the hole injection layer 50, improve interface defects, improve interface contact, and reduce interface resistance.

[0038] The surface roughness Rq1 of the second interface layer 72 is 0.1 to 1.0 nm; for example, it can be 0.1 nm, 0.2 nm, 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1.0 nm, or any two of the above values.

[0039] Please see Figure 3In some embodiments, the optoelectronic device 100 further includes a third interface layer 73, which is disposed between the first interface layer 71 and the hole transport layer 40. The interface stress between the third interface layer 73 and the hole transport layer 40 or between the third interface layer 73 and the first interface layer 71 is 2 to 6 Pa; for example, it can be 2 Pa, 3 Pa, 4 Pa, 5 Pa, 6 Pa, or any two of the above values. After setting the third interface layer 73, it helps to reduce the interface stress between the first interface layer 71 and the hole transport layer 40, improve interface defects, improve interface contact, and reduce interface resistance.

[0040] The surface roughness Rq2 of the third interface layer 73 is 0.1 to 1.0 nm; for example, it can be 0.1 nm, 0.2 nm, 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1.0 nm, or any two of the above values.

[0041] This is understandable; please refer to [link / reference]. Figure 3 In some embodiments, the optoelectronic device 100 may also include a second interface layer 72 and a third interface layer 73. The optoelectronic device 100 may include a stacked anode 10, a hole injection layer 50, a second interface layer 72, a first interface layer 71, a third interface layer 73, a hole transport layer 40, a light-emitting layer 30, and a cathode 20. This can improve interface defects between the first interface layer 71 and the hole transport layer 40, and between the first interface layer 71 and the hole injection layer 50, improve interface contact, and reduce interface resistance.

[0042] Interfacial stress refers to the interaction force generated at the contact interface between two film layers. It can be detected by X-ray diffraction.

[0043] Rq1 and Rq2 refer to the root mean square surface roughness, which is the root mean square value of the profile deviating from the average line within the sampling length. It can be obtained by atomic force microscopy (AFM).

[0044] In some embodiments, the thickness of the second interface layer 72 can be 5 to 10 nm; for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any two of the above values.

[0045] In some embodiments, the thickness of the third interface layer 73 can be 5 to 10 nm; for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or any two of the above values.

[0046] In some embodiments, the materials of the second interface layer 72 and the third interface layer 73 each independently include one or more of metal salts and metal hydroxides. The metal salts include one or more of magnesium carbonate, magnesium sulfate, calcium sulfate, and calcium carbonate, and the metal hydroxides include one or more of calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and iron hydroxide. The metal salts and metal hydroxides can be deposited on the surface of the hole transport layer 40, the hole injection layer 50, or the first interface layer 71 to form a precipitated film layer with better surface roughness, namely the second interface layer 72 or the third interface layer 73, which helps to improve interface defects and enhance the bonding force between interfaces.

[0047] In some embodiments, the anode 10 and the cathode 20 can be selected from anodes 10 or cathodes commonly used in the art. Specifically, the anode 10 and the cathode 20 can each be independently selected from, but not limited to, doped metal oxide particle electrodes, composite electrodes of metal and metal oxides, graphene electrodes, carbon nanotube electrodes, metal electrodes, or alloy electrodes. The material of the doped metal oxide particle electrode is selected from indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, and aluminum-doped... The metal and metal oxide composite electrode is selected from one or more magnesium oxides, including AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, and ZnS / Al / ZnS. The material of the metal electrode is selected from one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg, and Ba. The " / " indicates a stacked structure; for example, the composite electrode AZO / Ag / AZO represents a three-layer stacked composite structure consisting of an AZO layer, an Ag layer, and an AZO layer. The thickness of the anode 10 can be 10–120 nm; for example, it can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, or any two of the above values. The thickness of the cathode 20 can be 10–120 nm; for example, it can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, or any two of the above values.

[0048] In some embodiments, the optoelectronic device 100 may further include a light-emitting layer 30 disposed between the hole transport layer 40 and the cathode 20. The material of the light-emitting layer 30 may be a conventional light-emitting material in the art, such as a quantum dot material or an organic light-emitting material. The organic light-emitting material is a material known in the art for use in the organic light-emitting layer 30, for example, it may be selected from, but is not limited to, at least one of diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, blue-emitting TBPe fluorescent materials, green-emitting TTPA fluorescent materials, orange-emitting TBRb fluorescent materials, and red-emitting DBP fluorescent materials. The quantum dot material is a quantum dot known in the art for use in the quantum dot light-emitting layer 30, for example, one of red quantum dots, green quantum dots, and blue quantum dots.Quantum dots can be selected from, but are not limited to, at least one of single-structure quantum dots, core-shell quantum dots, and perovskite semiconductor materials. The shell of the core-shell quantum dot comprises one or more layers. The material of the single-structure quantum dot, the core material of the core-shell quantum dot, and the shell material of the core-shell quantum dot independently include at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds. The group II-VI compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, etc. At least one of ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, Sn At least one of STe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V compounds include GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, and GaAlNP. At least one of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds include at least one of CuInS2, CuInSe2, and AgInS2; the perovskite semiconductor material is selected from doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors; the general structural formula of the inorganic perovskite semiconductor is AMX3, where A is Cs. + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following. The thickness of the light-emitting layer 30 can be 20 to 60 nm; for example, it can be 20 nm, 25 nm, 30 nm, 40 nm, 45 nm, 50 nm, 52 nm, 54 nm, 55 nm, 56 nm, 58 nm, 60 nm, and any two of the above values.

[0049] As an example, the core-shell structured quantum dots may be selected from, but are not limited to, at least one of CdZnSe / CdZnSe / ZnSe / CdZnS / ZnS, CdZnSe / CdZnSe / CdZnS / ZnS, CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS. It should be noted that for the aforementioned materials consisting of single-structure quantum dots, or core-shell structure quantum dots, or shell-structure quantum dots, 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。

[0050] In some embodiments, the optoelectronic device 100 further includes an electron transport layer 60 disposed between the hole transport layer 40 and the cathode 20. The electron transport layer 60 is made of at least one of a metal oxide and a doped metal oxide. The metal oxide includes one or more of ZnO, TiO2, and SnO2. The doped metal oxide includes one or more of ZnO, TiO2, and SnO2. The doping element includes one or more of Al, Mg, Li, In, and Ga. The thickness of the electron transport layer is 40–60 nm; for example, it can be 40 nm, 43 nm, 45 nm, 48 nm, 50 nm, 52 nm, 54 nm, 55 nm, 56 nm, 58 nm, 60 nm, or any two of the above values.

[0051] It is understood that the optoelectronic device 100 may also be provided with some functional layers that are conventionally used in optoelectronic devices 100 and help to improve the performance of optoelectronic devices 100, such as electron blocking layer, hole blocking layer, interface modification layer, etc.

[0052] It is understood that the materials of each layer of the optoelectronic device 100 can be adjusted according to the actual needs of the optoelectronic device 100.

[0053] It is understood that the optoelectronic device 100 can be an upright device or an inverted device.

[0054] Secondly, this application also proposes a method for fabricating an optoelectronic device 100, the method comprising:

[0055] S10 provides the first electrode;

[0056] S20, providing a film layer sequence, wherein multiple film layers are sequentially disposed on one side of the first electrode according to the film layer sequence, the multiple film layers including a hole injection layer 50, a first interface layer 71 and a hole transport layer 40;

[0057] S30, a second electrode is disposed on the side of the plurality of films opposite to the first electrode to obtain an optoelectronic device 100.

[0058] The first electrode is selected from one of the anode 10 and the cathode 20, and the second electrode is selected from the other of the anode 10 and the cathode 20. In actual fabrication, the first electrode can be set according to the stacking order of the film layers of the optoelectronic device 100. For example, for an upright device, the first electrode is the anode 10 and the second electrode is the cathode 20. Conversely, when the optoelectronic device 100 is an inverted device, the first electrode is the cathode 20 and the second electrode is the anode 10.

[0059] The film layer sequence refers to the stacking and preparation order of multiple film layers located between the anode 10 and the cathode 20. It can be that the hole injection layer 50, the first interface layer 71, and the hole transport layer 40 are stacked sequentially from the anode 10 to the cathode 20. It can be understood that when the first electrode is the anode 10, the preparation order of the multiple film layers is to prepare the hole injection layer 50, the first interface layer 71, and the hole transport layer 40 sequentially from bottom to top. When the first electrode is the cathode 20, the preparation order of the multiple film layers is to prepare the hole transport layer 40, the first interface layer 71, and the hole injection layer 50 sequentially from bottom to top.

[0060] The HOMO level of the first interface layer 71 is located between the HOMO level of the hole transport layer 40 and the HOMO level of the hole injection layer 50.

[0061] It is understood that when multiple film layers include one or more of the following: a second interface layer 72, a third interface layer 73, a light-emitting layer 30, and an electron transport layer 60, the added film layers can be fabricated at corresponding positions according to the film layer stacking order of the optoelectronic device 100 described above. For example, if the second interface layer 72 is located between the hole injection layer 50 and the first interface layer 71, then the corresponding film layer order includes the hole injection layer 50, the second interface layer 72, the first interface layer 71, and the hole transport layer 40 stacked sequentially from the anode 10 to the cathode 20; similarly, if the third interface layer 73 is located between the hole transport layer 40 and the first interface layer 71, then the corresponding film layer order includes the hole injection layer 50, the first interface layer 71, the third interface layer 73, and the hole transport layer 40 stacked sequentially from the anode 10 to the cathode 20. When multiple film layers also include a second interface layer 72 and a third interface layer 73, the film layers sequentially include the hole injection layer 50, the second interface layer 72, the first interface layer 71, the third interface layer 73, the hole transport layer 40, and the light-emitting layer 30 stacked in sequence from the anode 10 to the cathode 20.

[0062] In some embodiments, the step of setting the first interface layer 71 includes: providing a first solution containing a material of the first interface layer 71, depositing the first solution to obtain the first interface layer 71; wherein the HOMO energy level of the material of the first interface layer 71 is -5.4 to -5.1 eV.

[0063] In some specific embodiments, the material of the first interface layer 71 includes any one of organic small molecule materials, polymer materials, and inorganic materials; for example, the organic small molecule materials may include one or more of aromatic amine compounds, carbazole compounds, and 4-bromotriphenylamine, wherein the aromatic amine compounds include one or more of N,N'-diaryl-N,N'-diphenylaniline and N,N,N',N'-tetraphenylaniline, and the carbazole compounds include one or more of 3,6-diphenylcarbazole, N-methylcarbazole, and 9-ethyl-3-carbazole carboxylic acid; the polymer materials include one or more of polyaniline, polyamide, polysiloxane, and polystyrene; the inorganic materials include one or more of metal oxides and transition metal complexes, wherein the metal oxides include one or more of molybdenum oxide and vanadium oxide, and the transition metal complexes include Fe(CO)5 and [Co(CN)6]. 3- [Fe(PO4)2] 3- One or more of them.

[0064] In some embodiments, the first solution further includes a first solvent. The first solvent may include, but is not limited to, C1-C8 alcohol solvents, such as methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, etc. It is understood that the alcohol solvents listed herein may also include their isomers. For example, with propanol, the first solvent may be n-propanol or isopropanol.

[0065] In some embodiments, the concentration of the first interface layer 71 material in the first solution is 20 to 40 mg / mL; for example, it can be 20 mg / mL, 25 mg / mL, 30 mg / mL, 35 mg / mL, 40 mg / mL, or any two of the above values.

[0066] The deposition method can be a solution method, such as spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating.

[0067] In some embodiments, after depositing the first mixed solution to form a liquid film, it can be solidified into a film by placing it in a vacuum environment for static treatment or by heat treatment. The heat treatment temperature can be 150–200°C, for example, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, or any two of the above values; the heat treatment time can be 10–40 minutes, for example, 10 minutes, 20 minutes, 30 minutes, 40 minutes, or any two of the above values.

[0068] In some embodiments, the interfacial stress between the second interface layer 72 and the hole injection layer 50 or the first interface layer 71 is 2 to 6 Pa; the surface roughness Rq1 of the second interface layer 72 is 0.1 to 1.0 nm; the material of the second interface layer 72 may include, but is not limited to, one or more of metal salts and metal hydroxides, wherein the metal salts include one or more of magnesium carbonate, magnesium sulfate, calcium sulfate, and calcium carbonate, and the metal hydroxides include one or more of calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and iron hydroxide.

[0069] The second interface layer 72 can be formed by a precipitation reaction. In some embodiments, the step of setting the second interface layer 72 may include:

[0070] S201a, providing a first cation solution containing a first metal cation and a first anion solution containing a first anion;

[0071] S202a, the upper membrane layer is immersed in a mixed solution of the first cation solution and the first anion solution, and the first metal cation combines with the first anion and deposits on one side of the upper membrane layer to form a second interface layer 72.

[0072] The "upper film layer" refers to a film layer prepared in a process prior to the preparation of the second interface layer 72 during the preparation of multiple film layers. In the optoelectronic device 100, it is located below the second interface layer 72 in the stacking direction. For example, in an upright device, the upper film layer of the second interface layer 72 is the hole injection layer 50; in an inverted device, the upper film layer of the second interface layer 72 is the first interface layer 71.

[0073] Based on the material of the second interface layer 72 described above, the first cation solution and the first anion solution can satisfy the following condition: the first metal cation is selected from Mg. 2+ Ca 2+ Fe 3+ Al 3+ Any one of the following, wherein the first metal cation is selected from Mg 2+ Or Ca 2+ In this case, the first anion is selected from SO4. 2- CO3 2- Or OH - The first metal cation is selected from Fe 3 + Or Al 3+ When the first anion is OH- - It can be understood that the first cation refers to the cation of the material constituting the second interface layer 72, and the first anion refers to the anion of the material constituting the second interface layer 72. Taking magnesium sulfate as an example, the first cation is Mg. 2+ The first anion is SO42-. 2- .

[0074] The first metal cation is provided by the solute of the first cation solution, and the solute of the first cation solution includes any one of calcium chloride, calcium nitrate, magnesium chloride, magnesium nitrate, ferric chloride, ferric nitrate, aluminum chloride, and aluminum nitrate; the solvent of the first cation solution is selected from C1 to C8 alcohol solvents, and the C1 to C8 alcohol solvents include one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol.

[0075] The first anion is provided by the first anion solution, which is an alkaline solution or an alcoholic solution of a salt compound. The alkaline solution includes one or more of the following: an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, and ammonia. The salt compound includes one or more of the following: sodium carbonate, potassium carbonate, sodium sulfate, and potassium sulfate. The alcohol includes C1-C8 alcohol solvents, which include one or more of the following: methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol.

[0076] It is understood that when the solute of the first cation solution is selected from any one of calcium chloride, calcium nitrate, magnesium chloride, and magnesium nitrate, the first anion solution can be selected from any of the alkaline solutions or alcoholic solutions of salt compounds listed above, thereby obtaining a second interface layer 72 made of magnesium carbonate, magnesium sulfate, calcium sulfate, calcium carbonate, calcium hydroxide, or magnesium hydroxide; when the solute of the first cation solution is selected from any one of ferric chloride, ferric nitrate, aluminum chloride, and aluminum nitrate, the solute of the first anion solution can be selected from any of the alkaline solutions listed above, thereby obtaining a second interface layer 72 made of aluminum hydroxide or ferric hydroxide.

[0077] In some embodiments, the concentration of the solute in the first cation solution can be 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, and any two of the above values.

[0078] In some embodiments, when the first anionic solution is an alcoholic solution of a salt compound, the concentration of the salt compound can be 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, or any two of the above values; when the first anionic solution is an alkaline solution, the concentration of the alkaline solution can be 1 to 30 wt%, for example, 1%, 2%, 3%, 4%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, or any two of the above values.

[0079] In step S202a, the step of immersing the upper membrane layer in the mixed solution of the first cation solution and the first anion solution can be implemented in the following manner: the membrane surface of the upper membrane layer is brought into contact with the first cation solution, and then the first anion solution is added dropwise to the first cation solution, so that the first metal cation and the first anion are fully in contact and a precipitation reaction is carried out, thereby forming a second interface layer 72 on the membrane surface.

[0080] To better control the film-forming effect of the second interface layer 72, the solution can be heated and stirred while mixing the first cation solution and the first anion solution. The temperature can be controlled within the range of 50–70°C, and the stirring speed within the range of 2500–3500 r / s. By controlling the reaction temperature and stirring speed within the above ranges, the precipitation reaction rate can be controlled, the precipitate particle size can be adjusted, and the precipitate can be uniformly precipitated on the film surface, thus improving the film-forming effect. Specifically, the heating temperature can be 50°C, 55°C, 60°C, 65°C, 70°C, or any two of the above values; the stirring speed can be 2500 r / s, 2600 r / s, 2700 r / s, 2800 r / s, 2900 r / s, 3000 r / s, 3100 r / s, 3200 r / s, 3300 r / s, 3400 r / s, 3500 r / s, or any two of the above values. In some embodiments, the time for immersing the upper membrane layer in the mixed solution of the first cation solution and the first anion solution can be 8 to 15 minutes to ensure that the reaction proceeds fully. The precipitation reaction time can be 8 to 15 minutes; for example, it can be 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, or any two of the above values.

[0081] In some embodiments, the interfacial stress between the third interface layer 73 and the hole transport layer 40 or the first interface layer 71 is 2 to 6 Pa; the surface roughness Rq2 of the third interface layer 73 is 0.1 to 1.0 nm; the material of the third interface layer 73 may include, but is not limited to, one or more of metal salts and metal hydroxides, wherein the metal salts include one or more of magnesium carbonate, magnesium sulfate, calcium sulfate, and calcium carbonate, and the metal hydroxides include one or more of calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and iron hydroxide.

[0082] The third interface layer 73 can be formed by a precipitation reaction. In some embodiments, the step of setting the third interface layer 73 may include:

[0083] S201b provides a second cation solution containing a second metal cation and a second anion solution containing a second anion;

[0084] S202b, the upper membrane layer is immersed in a mixed solution of the second cation solution and the second anion solution, and the second metal cation combines with the second anion and deposits on one side of the upper membrane layer to form a third interface layer 73.

[0085] The upper film layer refers to the film layer prepared in a process before the preparation of the third interface layer 73 during the preparation of multiple film layers. In the optoelectronic device 100, it is located below the third interface layer 73 in the stacking direction. For example, in an upright device, the upper film layer of the third interface layer 73 is the first interface layer 71; in an inverted device, the upper film layer of the third interface layer 73 is the hole transport layer 40.

[0086] Based on the material of the third interface layer 73 described above, the first cation solution and the first anion solution can satisfy the following condition: the second metal cation is selected from Mg. 2+ Ca 2+ Fe 3+ Al 3+ Any one of them, and the second metal cation is selected from Mg 2+ Or Ca 2+ At that time, the second anion was selected from SO4. 2- CO3 2- Or OH - The second metal cation is selected from Fe. 3 + Or Al 3+ When the second anion is OH- - .

[0087] The second metal cation is provided by the solute of the second cation solution, which includes any one of calcium chloride, calcium nitrate, magnesium chloride, magnesium nitrate, ferric chloride, ferric nitrate, aluminum chloride, and aluminum nitrate; the solvents of the second cation solution are each independently selected from C1 to C8 alcohol solvents, which include one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol.

[0088] The second anion is provided by a second anion solution, which is an alkaline solution or an alcoholic solution of a salt compound. The alkaline solution includes one or more of an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, and ammonia. The salt compound includes one or more of sodium carbonate, potassium carbonate, sodium sulfate, and potassium sulfate. The alcohol includes C1-C8 alcohol solvents, which include one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol.

[0089] In some embodiments, the concentration of the solute in the second cation solution can be 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, and any two of the above values.

[0090] In some embodiments, when the second anionic solution is an alcoholic solution of a salt compound, the concentration of the salt compound can be 5 to 30 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, or any two of the above values; when the second anionic solution is an alkaline solution, the concentration of the alkaline solution can be 1 to 30 wt%, for example, 1%, 2%, 3%, 4%, 5%, 8%, 10%, 15%, 20%, 25%, 30%, or any two of the above values.

[0091] In step S202a, the step of immersing the upper membrane layer in the mixed solution of the second cation solution and the second anion solution can be carried out in the following manner: the membrane surface of the upper membrane layer is brought into contact with the second cation solution, and then the second anion solution is added dropwise to the first cation solution, so that the second metal cation and the second anion are fully in contact and a precipitation reaction is carried out, thereby forming a third interface layer 73 on the membrane surface.

[0092] To better control the film-forming effect of the third interface layer 73, the solution can be heated and stirred while mixing the second cation solution and the second anion solution. The temperature can be controlled within the range of 50–70°C, and the stirring speed within the range of 2500–3500 r / s. By controlling the reaction temperature and stirring speed within the above ranges, the precipitation reaction rate can be controlled, the precipitate particle size can be adjusted, and the precipitate can be uniformly precipitated on the film surface, thus improving the film-forming effect. Specifically, the heating temperature can be 50°C, 55°C, 60°C, 65°C, 70°C, or any two of the above values; the stirring speed can be 2500 r / s, 2600 r / s, 2700 r / s, 2800 r / s, 2900 r / s, 3000 r / s, 3100 r / s, 3200 r / s, 3300 r / s, 3400 r / s, 3500 r / s, or any two of the above values. In some embodiments, the time for immersing the upper membrane layer in the mixed solution of the second cation solution and the second anion solution can be 8 to 15 minutes to ensure that the reaction proceeds fully. The precipitation reaction time can be 8 to 15 minutes; for example, it can be 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, or any range between two of the above values.

[0093] In some embodiments, in steps S202a and S202b, before the surface of the previous membrane layer comes into contact with the mixed solution, the membrane surface may be cleaned to remove impurities and facilitate the adhesion of subsequent precipitates. The cleaning solution used during cleaning may be an alcohol solvent.

[0094] In some embodiments, in steps S202a and S202b, after forming the film layer through the precipitation reaction, it can be solidified into a film by placing it in a vacuum environment for static treatment or by heat treatment. The heat treatment temperature can be 100–140°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, or any two of the above values; the heat treatment time can be 5–15 min, for example, 5 min, 8 min, 10 min, 12 min, 15 min, or any two of the above values.

[0095] In addition, the methods for forming the anode 10, cathode 20, and light-emitting layer 30 can be chemical or physical methods. Chemical methods include chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition, and co-precipitation. Physical methods include physical deposition or solution processing. Physical deposition methods include thermal evaporation deposition (CVD), electron beam evaporation deposition, magnetron sputtering, multi-arc ion deposition, physical vapor deposition (PVD), atomic layer deposition, and pulsed laser deposition. Solution processing methods include spin coating, printing, inkjet printing, blade coating, dip coating, immersion coating, spraying, roller coating, casting, slot coating, and strip coating. Those skilled in the art can prepare the various film layers of the optoelectronic device 100 of this application embodiment according to the known methods for preparing optoelectronic devices 100, which will not be elaborated further here.

[0096] Thirdly, this application also relates to a display device, which includes the optoelectronic device 100 provided in this application, or the optoelectronic device 100 prepared by the preparation method described above. The display device can be any electronic product with display function, including but not limited to smartphones, tablets, laptops, digital cameras, digital camcorders, smart wearable devices, smart weighing scales, in-vehicle displays, televisions, or e-book readers. Among them, smart wearable devices can be, for example, smart bracelets, smartwatches, virtual reality (VR) headsets, etc.

[0097] The present application will be specifically described below through specific embodiments. These embodiments are only some embodiments of the present application and are not intended to limit the present application. Unless otherwise specified, the raw materials used in the following embodiments are all commercially available products.

[0098] Example 1

[0099] Step S1: Spin-coat PEDOT:PSS onto an ITO substrate at 5000 rpm for 30 seconds, then heat at 150°C for 15 minutes to obtain a hole injection layer with a thickness of 50 nm.

[0100] Step S2: Spin-coat a polysiloxane ethanol solution (concentration of 30 mg / mL) onto the hole injection layer at a speed of 6000 rpm for 30 seconds, followed by heating at 150°C for 15 minutes to obtain a first interface layer with a thickness of 8 nm.

[0101] Step S3: Spin-coat a chlorobenzene solution of TFB (TFB concentration of 8 mg / mL) at 3000 rpm for 30 seconds, followed by heating at 120°C for 10 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0102] Step S4: Spin-coat a hexane solution of green quantum dots ZnCdSe / ZnS (quantum dot concentration of 20 mg / mL) onto the hole transport layer at 2000 rpm for 30 seconds, followed by heating at 100°C for 5 minutes to obtain a light-emitting layer with a thickness of 25 nm.

[0103] Step S5: Spin-coat an ethanol solution of ZnO (ZnO concentration of 30 mg / mL) onto the luminescent layer at a speed of 3000 rpm for 30 seconds, followed by heating at 80°C for 10 minutes to obtain an electron transport layer with a thickness of 45 nm.

[0104] Step S6: Through thermal evaporation, the vacuum level is not higher than 3×10. -4 Pa, Ag was deposited on the electron transport layer at a speed of 1 angstrom / second for 200 seconds, with a thickness of 20 nm;

[0105] Step S7: Encapsulate the device with epoxy resin to obtain a QLED device with the following structure: ITO / / PEDOT:PSS (-5.2ev) / / polysiloxane (-5.26ev) / / TFB (-5.3ev) / / QD / / ZnO / / Ag.

[0106] Example 2

[0107] The scheme of this embodiment is basically the same as that of embodiment 1, except that the device in this embodiment also includes a CaCO3 precipitate layer, specifically ITO / / PEDOT:PSS / / CaCO3 / / polysiloxane / / TFB / / QD / / ZnO / / Ag. Correspondingly, in the preparation method, the following steps are also included between steps S1 and S2:

[0108] The surface of the hole injection layer is cleaned with ethanol. Then, the semi-finished device prepared in step S1 is inserted into a calcium chloride ethanol solution (calcium chloride concentration is 10 mg / ml), so that the side of the hole injection layer away from ITO is immersed in the calcium chloride ethanol solution. Then, a sodium carbonate ethanol solution (sodium carbonate concentration is 10 mg / ml) is slowly added dropwise. The reaction is carried out at 60°C and 3000 r / s stirring speed for 10 min. Calcium carbonate precipitate gradually adheres to the surface of the hole injection layer to form a thin film. The film is then cleaned with ethanol and heated at 120°C for 10 min to obtain a second interface layer with a thickness of 8 nm. The second interface layer is used to prepare the first interface layer in S2.

[0109] Example 3

[0110] The scheme of this embodiment is basically the same as that of embodiment 1, except that the device in this embodiment also includes a precipitated layer Al(OH)3, specifically ITO / / PEDOT:PSS / / Al(OH)3 / / polysiloxane / / TFB / / QD / / ZnO / / Ag. Correspondingly, in the preparation method, the following steps are also included between steps S1 and S2:

[0111] The surface of the hole injection layer is cleaned with ethanol. Then, the semi-finished device prepared in step S1 is inserted into an ethanol solution of aluminum nitrate (the concentration of aluminum nitrate is 10 mg / ml), so that the side of the hole injection layer away from ITO is immersed in the ethanol solution of aluminum nitrate. Then, an aqueous ammonia solution (concentration of 25 wt%) is slowly added dropwise. The reaction is carried out at 60°C and 3000 r / s stirring speed for 10 min. Aluminum hydroxide precipitate gradually adheres to the surface of the hole injection layer to form a thin film. The film is then cleaned with ethanol and heated at 120°C for 10 min to obtain a second interface layer with a thickness of 8 nm. The second interface layer is used to prepare the first interface layer in S2.

[0112] Example 4

[0113] The scheme of this embodiment is basically the same as that of embodiment 1, except that the device in this embodiment also includes two precipitated layers of CaCO3, specifically ITO / / PEDOT:PSS / / CaCO3 / / polysiloxane / / CaCO3 / / TFB / / QD / / ZnO / / Ag. Correspondingly, in the preparation method, step S10 is added between steps S1 and S2, and step S20 is added between steps S2 and S3.

[0114] Step S10: Clean the surface of the hole injection layer with ethanol; then insert the semi-finished device prepared in step S1 into a calcium chloride ethanol solution (calcium chloride concentration is 10 mg / ml), so that the side of the hole injection layer away from ITO is immersed in the calcium chloride ethanol solution, and then slowly add an ethanol solution of sodium carbonate (sodium carbonate concentration is 10 mg / ml). Under the stirring speed of 3000 r / s at 60℃, react for 10 min. The calcium carbonate precipitate gradually adheres to the surface of the hole injection layer to form a thin film. Then clean the film with ethanol, and then heat at 120℃ for 10 min to obtain a second interface layer with a thickness of 8 nm. The second interface layer is used to prepare the first interface layer in S2.

[0115] Step S20: Clean the surface of the first interface layer with ethanol; then insert the semi-finished device prepared in step S2 into a calcium chloride ethanol solution (calcium chloride concentration is 10 mg / ml), so that the side of the first interface layer away from the second interface layer is immersed in the calcium chloride ethanol solution, and then slowly add an ethanol solution of sodium carbonate (sodium carbonate concentration is 10 mg / ml). Under the stirring speed of 3000 r / s at 60℃, react for 10 min. The calcium carbonate precipitate gradually adheres to the surface of the first interface layer to form a thin film. Then clean the thin film with ethanol, and then heat it at 120℃ for 10 min to obtain a third interface layer with a thickness of 8 nm. The surface of the third interface layer is used to prepare the hole transport layer in S3.

[0116] Example 5

[0117] The scheme in this embodiment is basically the same as that in embodiment 2, except that the structure of the device in this embodiment is ITO / / PEDOT:PSS / / CaCO3 / / polyaniline / / TFB / / QD / / ZnO / / Ag. Correspondingly, in the preparation method, polysiloxane is replaced with polyaniline (-5.22ev).

[0118] Example 6

[0119] The scheme in this embodiment is basically the same as that in embodiment 2, except that the structure of the device in this embodiment is ITO / / PEDOT:PSS / / CaCO3 / / 9-ethyl-3-carbazole carboxylic acid / / TFB / / QD / / ZnO / / Ag. Correspondingly, in the preparation method, polysiloxane is replaced with 9-ethyl-3-carbazole carboxylic acid (-5.29ev).

[0120] Example 7

[0121] The scheme of this embodiment is basically the same as that of embodiment 2, except that the structure of the device in this embodiment is ITO / / PEDOT:PSS / / CaCO3 / / Fe(CO)5 / / TFB / / QD / / ZnO / / Ag. Correspondingly, in the preparation method, polysiloxane is replaced with Fe(CO)5 (-5.23ev).

[0122] Example 8

[0123] The scheme in this embodiment is basically the same as that in embodiment 2, except that the thickness of the first interface layer is changed from 8nm to 5nm.

[0124] Example 9

[0125] The scheme in this embodiment is basically the same as that in embodiment 2, except that the thickness of the first interface layer is changed from 8nm to 10nm.

[0126] Example 10

[0127] The scheme in this embodiment is basically the same as that in embodiment 2, except that the thickness of the first interface layer is changed from 8nm to 12nm.

[0128] Example 11

[0129] The scheme in this embodiment is basically the same as that in embodiment 1, except that this embodiment is an inverted device with the structure Ag / / ZnO / / QD / / TFB / / polysiloxane / / PEDOT:PSS / / ITO. The corresponding preparation steps are as follows:

[0130] Step S1: Through thermal evaporation, the vacuum level is not higher than 3×10⁻⁶. -4 Pa is used to deposit Ag on a substrate with a thickness of 100 nm to obtain the cathode.

[0131] Step S2: Spin-coat an ethanol solution of ZnO (ZnO concentration of 30 mg / mL) onto the cathode at a speed of 3000 rpm for 30 seconds, followed by heating at 80°C for 10 minutes to obtain an electron transport layer with a thickness of 45 nm.

[0132] Step S3: Spin-coat a hexane solution of green quantum dots ZnCdSe / ZnS (quantum dot concentration of 20 mg / mL) onto the electron transport layer at 2000 rpm for 30 seconds, followed by heating at 100°C for 5 minutes to obtain a light-emitting layer with a thickness of 25 nm.

[0133] Step S4: Spin-coat a chlorobenzene solution of TFB (TFB concentration of 8 mg / mL) onto the luminescent layer at 3000 rpm for 30 seconds, followed by heating at 120°C for 10 minutes to obtain a hole transport layer with a thickness of 30 nm.

[0134] Step S5: Spin-coat a polysiloxane ethanol solution (concentration of 30 mg / mL) onto the hole transport layer at a speed of 6000 rpm for 30 seconds, and then heat at 150°C for 15 minutes to obtain a first interface layer with a thickness of 8 nm.

[0135] Step S6: Spin coat PEDOT:PSS onto the first interface layer at a speed of 5000 rpm for 30 seconds, then heat at 150°C for 15 minutes to obtain a hole injection layer with a thickness of 50 nm.

[0136] Step S7: ITO anode is deposited on the hole injection layer by thermal evaporation, and then epoxy resin encapsulation is performed to obtain QLED device.

[0137] Example 12

[0138] The scheme of this embodiment is basically the same as that of embodiment 11, except that this embodiment is an inverted device and the structure also includes a CaCO3 precipitate layer, specifically Ag / / ZnO / / QD / / TFB / / CaCO3 / / polysiloxane / / PEDOT:PSS / / ITO. Accordingly, in the preparation steps, the following steps are added between steps S4 and S5:

[0139] The surface of the hole injection layer is cleaned with ethanol. Then, the semi-finished device prepared in step S1 is inserted into a calcium chloride ethanol solution (calcium chloride concentration is 10 mg / ml), so that the side of the hole injection layer away from ITO is immersed in the calcium chloride ethanol solution. Then, a sodium carbonate ethanol solution (sodium carbonate concentration is 10 mg / ml) is slowly added dropwise. The reaction is carried out at 60°C and 3000 r / s stirring speed for 10 min. The calcium carbonate precipitate gradually adheres to the surface of the hole injection layer to form a thin film. The film is then cleaned with ethanol and heated at 120°C for 10 min to obtain a second interface layer with a thickness of 8 nm. The second interface layer is used to prepare the first interface layer in S5.

[0140] Comparative Example 1

[0141] The comparative example scheme is basically the same as that of Example 1, except that the first interface layer is removed from the device structure of this comparative example. The specific structure is ITO / / PEDOT:PSS / / TFB / / QD / / ZnO / / Ag.

[0142] Comparative Example 2

[0143] The comparative example scheme is basically the same as that of Example 11, except that the first interface layer is removed from the device structure of this comparative example. The specific structure is Ag / / ZnO / / QD / / TFB / / PEDOT:PSS / / ITO.

[0144] Experimental Example

[0145] The QLED devices prepared in the above embodiments and comparative examples were subjected to performance tests. The test items included: surface roughness, current density of a single hole device at 4V, and the external quantum efficiency (EQE) and lifetime (T95-1K) of the QLED devices. The test results are recorded in Tables 1-1 and 1-2. The test methods are as follows:

[0146] (1) The surface roughness is detected by observing the thin film with an atomic force microscope and detecting the surface roughness Rq.

[0147] (2) The method for detecting interfacial stress is: X-ray diffraction. Specifically, if the interfacial stress to be detected is the interfacial stress between film layer A and film layer B, the detection can be carried out after film layer A is prepared on film layer B.

[0148] (3) The method for detecting the current density of the HOD device at 4V is as follows: Corresponding to the fabrication methods provided in the above device embodiments and comparative examples, their respective corresponding hole-only devices (HODs) are fabricated, and the current density-voltage curve of the hole-only device is tested. The current density of the HOD device at 4V is compared. The fabrication method of the hole-only device is basically the same as the fabrication method of its corresponding complete QLED device, the only difference being the removal of the electron transport layer ZnO.

[0149] (4) External quantum dot efficiency (EQE):

[0150] The ratio of electron-hole pairs injected into a quantum dot to emitted photons, expressed as a percentage (%), is an important parameter for evaluating the quality of electroluminescent devices. It can be measured using an EQE optical testing instrument. The specific calculation formula is as follows:

[0151]

[0152] In the formula, η e For optical output coupling efficiency, η r K represents the ratio of recombination carriers to injected carriers, x represents the ratio of excitons producing photons to the total number of excitons, and K represents the ratio of recombination carriers to injected carriers. R K is the radiation process rate. NR This represents the rate of a non-radiative process.

[0153] Test conditions: Conducted at room temperature with an air humidity of 30-60%.

[0154] (5) QLED Device Lifetime: The time required for the brightness of a device to decrease to a certain percentage of its maximum brightness under constant current or voltage driving. The time for the brightness to decrease to 95% of the maximum brightness is defined as T95, which is the measured lifetime. To shorten the testing cycle, device lifetime testing is usually performed by accelerating device aging at high brightness, referencing OLED device testing. The lifetime at high brightness is obtained by fitting the extended exponential decay brightness decay fitting formula, for example, the lifetime at 1000 nits is measured as T95. 1000nit The specific calculation formula is as follows:

[0155]

[0156] In the formula, T95 L For longer lifespan at low brightness, T95 H For the measured lifetime under high brightness, L H To accelerate the device to its maximum brightness, L L The value is 1000 nits, and A is the acceleration factor. For OLEDs, this value is usually 1.6 to 2. In this experiment, the lifetime of several groups of QLED devices under rated brightness was measured, and the value of A was found to be 1.7.

[0157] The life test system was used to test the life of the corresponding devices. The test conditions were: room temperature and air humidity of 30-60%.

[0158] Table 1-1

[0159]

[0160]

[0161] Table 1-2

[0162]

[0163]

[0164] As can be seen from the table above:

[0165] Compared to Comparative Example 1, Examples 1 to 10 all exhibit higher EQE and T95. 1000nit Furthermore, their respective HOD devices exhibit high current density at 4V. Additionally, compared to Comparative Example 2, Examples 11 and 12 both demonstrate higher EQE and T95. 1000nit Furthermore, the corresponding HOD devices have a high current density at 4V, indicating that by setting a first interface layer between the hole transport layer and the hole injection layer, this application helps to improve the hole injection efficiency and enhance the luminous efficiency and lifespan of the device.

[0166] Furthermore, in Examples 2-10 and Example 12, the second or third interface layer exhibits lower surface roughness, and the interfacial stress at the location of the second or third interface layer decreases compared to Examples 1 and 10, indicating that the second or third interface layer helps improve film surface defects. Combining the comparison between Examples 2-10 and Example 1, and between Examples 12 and Example 11, Examples 2-10 and Example 12 show improvements in EQE and T95. 1000nit Furthermore, the HOD device showed better performance in current density at 4V, indicating that the setting of the second and third interface layers helps to further improve interface resistance, improve hole injection, and improve the luminous efficiency and lifespan of the device.

[0167] The technical solutions provided by the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An optoelectronic device, characterized in that, It includes a stacked anode, a hole injection layer, a first interface layer, a hole transport layer, and a cathode; The HOMO level of the first interface layer is located between the HOMO level of the hole transport layer and the HOMO level of the hole injection layer.

2. The optoelectronic device according to claim 1, characterized in that, The thickness of the first interface layer is 5–10 nm; and / or, The thickness of the hole transport layer is 30–50 nm; and / or, The thickness of the hole injection layer is 30–50 nm; and / or, The HOMO level of the hole transport layer is lower than the HOMO level of the first interface layer, and the HOMO level of the first interface layer is lower than the HOMO level of the hole injection layer; and / or, The HOMO energy level of the first interface layer is -5.4 to -5.1 eV; and / or, The HOMO level of the hole transport layer is less than or equal to -5.1 eV; and / or, The HOMO energy level of the hole injection layer is greater than or equal to -5.4 eV.

3. The optoelectronic device according to claim 2, characterized in that, The HOMO energy levels of the first interface layer are -5.36 to -5.21 eV; and / or, The HOMO energy level of the hole transport layer is -5.8 to -5.2 eV; and / or, The HOMO energy level of the hole injection layer is -5.3 to -5.1 eV.

4. The optoelectronic device according to claim 3, characterized in that, The material of the first interface layer includes any one of organic small molecule materials, polymer materials, and inorganic materials.

5. The optoelectronic device according to claim 4, characterized in that, The organic small molecule material includes one or more of aromatic amine compounds, carbazole compounds, and 4-bromotriphenylamine; the aromatic amine compounds include one or more of N,N'-diaryl-N,N'-diphenylaniline and N,N,N',N'-tetraphenylaniline; the carbazole compounds include one or more of 3,6-diphenylcarbazole, N-methylcarbazole, and 9-ethyl-3-carbazolecarboxylic acid; and / or... The polymer material includes one or more of polyaniline, polyamide, polysiloxane, and polystyrene; and / or, The inorganic material includes one or more of metal oxides and transition metal complexes; the metal oxides include one or more of molybdenum oxide and vanadium oxide; and the transition metal complexes include Fe(CO)5 and [Co(CN)6]. 3- [Fe(PO4)2] 3- One or more of them.

6. The optoelectronic device according to claim 1, characterized in that, The optoelectronic device further includes a second interface layer disposed between the first interface layer and the hole injection layer, wherein the interface stress between the second interface layer and the hole injection layer or the first interface layer is 2–6 Pa; and / or The optoelectronic device further includes a third interface layer, which is disposed between the first interface layer and the hole transport layer, and the interface stress between the third interface layer and the hole transport layer or the first interface layer is 2 to 6 Pa.

7. The optoelectronic device according to claim 6, characterized in that, The surface roughness Rq1 of the second interface layer is 0.1–1.0 nm; and / or, The surface roughness Rq2 of the third interface layer is 0.1–1.0 nm; and / or, The thickness of the second interface layer is 5–10 nm; and / or, The thickness of the third interface layer is 5–10 nm; and / or, The materials of the second interface layer and the third interface layer each independently include one or more of metal salts and metal hydroxides. The metal salts include one or more of magnesium carbonate, magnesium sulfate, calcium sulfate, and calcium carbonate. The metal hydroxides include one or more of calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and iron hydroxide.

8. The optoelectronic device according to claim 1, characterized in that, The hole transport layer is made of one or more of the following materials: poly[(9,9'-dioctylfluorenyl-2,7-diyl)-CO-(4,4'-(N-(p-butylphenyl))diphenylamine)], poly[bis(4-phenyl)(4-butylphenyl)amine], 4,4'-bis(9H-carbazole-9-yl)biphenyl, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, 4,4',4”-tris(carbazole-9-yl)triphenylamine, and poly(9-vinylcarbazole); and / or, The material of the hole injection layer includes PEDOT:PSS; and / or, The anode and the cathode are each independently selected from doped metal oxide particle electrodes, metal-metal oxide composite electrodes, graphene electrodes, carbon nanotube electrodes, metal electrodes, or alloy electrodes. The material of the doped metal oxide particle electrode is selected from one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, and aluminum-doped magnesium oxide. The metal-metal oxide composite electrode is selected from AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, and ZnS / Al / ZnS. The material of the metal electrode is selected from one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg, and Ba; and / or, The optoelectronic device further includes a light-emitting layer disposed between the cathode and the hole transport layer. The material of the light-emitting layer includes organic light-emitting materials or quantum dot materials. The organic light-emitting material includes at least one of diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, blue-emitting TBPe fluorescent materials, green-emitting TTPA fluorescent materials, orange-emitting TBRb fluorescent materials, and red-emitting DBP fluorescent materials. The quantum dot material includes at least one of single-structure quantum dots, core-shell quantum dots, and perovskite semiconductor materials. The shell of the core-shell quantum dot includes one or more layers. The material of the single-structure quantum dot, the core material of the core-shell quantum dot, and the... The shell material of the core-shell structured quantum dots includes at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds; the group II-VI compounds include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, Cd At least one of ZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds include at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds include GaN, GaP, GaAs, GaSb, and AlN. , AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, G At least one of aAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb;The group I-III-VI compounds include at least one of CuInS2, CuInSe2, and AgInS2; the perovskite semiconductor material is selected from doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors; the general structural formula of the inorganic perovskite semiconductor is AMX3, where A is Cs; + Ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2). n-2 NH3 + Or [NH3(CH2)] n NH3] 2+ Where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ Cu 2+ Ni 2 + Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ 、Ge 2+ Yb 2+ Eu 2+ At least one of them, where X is a halide anion selected from Cl. - ,Br - I - At least one of them.

9. A method for fabricating an optoelectronic device, characterized in that, Includes the following steps: Provide the first electrode; A film layer sequence is provided, wherein multiple film layers are sequentially disposed on one side of the first electrode according to the film layer sequence, the multiple film layers including a hole injection layer, a first interface layer and a hole transport layer; A second electrode is disposed on the side of the plurality of film layers opposite to the first electrode to obtain an optoelectronic device; Wherein, the first electrode is selected from one of the anode and the cathode, and the second electrode is selected from the other of the anode and the cathode; the film layer sequence includes the hole injection layer, the first interface layer and the hole transport layer stacked sequentially in the direction from the anode to the cathode; the HOMO energy level of the first interface layer is located between the HOMO energy level of the hole transport layer and the HOMO energy level of the hole injection layer.

10. The preparation method according to claim 9, characterized in that, The steps for setting the first interface layer include: A first solution containing a first interface layer is provided, and the first solution is deposited to obtain the first interface layer; The HOMO energy level of the material in the first interface layer is -5.4 to -5.1 eV.

11. The preparation method according to claim 10, characterized in that, The material of the first interface layer includes any one of organic small molecule materials, polymer materials, and inorganic materials; preferably, the organic small molecule material includes one or more of aromatic amine compounds, carbazole compounds, and 4-bromotriphenylamine, the aromatic amine compound includes one or more of N,N'-diaryl-N,N'-diphenylaniline and N,N,N',N'-tetraphenylaniline, the carbazole compound includes one or more of 3,6-diphenylcarbazole, N-methylcarbazole, and 9-ethyl-3-carbazole carboxylic acid; the polymer material includes one or more of polyaniline, polyamide, polysiloxane, and polystyrene; the inorganic material includes one or more of metal oxides and transition metal complexes, the metal oxide includes one or more of molybdenum oxide and vanadium oxide, and the transition metal complex includes Fe(CO)5 and [Co(CN)6]. 3- [Fe(PO4)2] 3- One or more of the following; and / or, The first solution further includes a first solvent, which comprises a C1-C8 alcohol solvent, wherein the C1-C8 alcohol solvent includes one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol; and / or, In the first solution, the concentration of the material of the first interface layer is 20–40 mg / mL.

12. The preparation method according to claim 10, characterized in that, The plurality of film layers further includes a second interface layer, and the film layers are sequentially stacked as follows: the hole injection layer, the second interface layer, the first interface layer, and the hole transport layer, in a direction from the anode to the cathode. The interfacial stress between the second interface layer and the hole injection layer or the first interface layer is 2–6 Pa; or... The plurality of film layers further includes a third interface layer, and the film layers are sequentially stacked as follows: the hole injection layer, the first interface layer, the third interface layer, and the hole transport layer, in a direction from the anode to the cathode. The interfacial stress between the third interface layer and the hole transport layer or the first interface layer is 2–6 Pa; or... The plurality of film layers further includes a second interface layer and a third interface layer. The film layers are stacked sequentially in the direction from the anode to the cathode, including the hole injection layer, the second interface layer, the first interface layer, the third interface layer, and the hole transport layer. The interface stress between the second interface layer and the hole injection layer or the first interface layer is 2 to 6 Pa, and the interface stress between the third interface layer and the hole transport layer or the first interface layer is 2 to 6 Pa.

13. The preparation method according to claim 12, characterized in that, The surface roughness Rq1 of the second interface layer is 0.1–1.0 nm; and / or, The surface roughness Rq2 of the third interface layer is 0.1–1.0 nm; and / or, The steps for setting the second interface layer include: A first cation solution containing a first metal cation and a first anion solution containing a first anion are provided; the upper film layer is immersed in a mixed solution of the first cation solution and the first anion solution to form a second interface layer; The upper film layer is either the hole injection layer or the first interface layer, and the first metal cation is selected from Mg. 2+ Ca 2+ Fe 3+ Al 3+ Any one of the following, wherein the first metal cation is selected from Mg 2+ Or Ca 2+ In this case, the first anion is selected from SO4. 2- CO3 2- Or OH - The first metal cation is selected from Fe. 3+ Or Al 3+ When the first anion is OH- - .

14. The preparation method according to claim 13, characterized in that, The solvent for the first cation solution is selected from C1-C8 alcohol solvents, including one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol; and / or, The first metal cation is provided by a solute in the first cation solution, wherein the solute in the first cation solution includes any one of calcium chloride, calcium nitrate, magnesium chloride, magnesium nitrate, ferric chloride, ferric nitrate, aluminum chloride, and aluminum nitrate; and / or, The first anion is provided by the first anion solution, which is an alkaline solution or an alcoholic solution of a salt compound. The alkaline solution includes one or more of the following: an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, and ammonia. The salt compound includes one or more of the following: sodium carbonate, potassium carbonate, sodium sulfate, and potassium sulfate. The alcohol includes C1-C8 alcohol solvents, which include one or more of the following: methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol.

15. The preparation method according to claim 12, characterized in that, The steps for setting the third interface layer include: Provides a second cation solution containing a second metal cation and a second anion solution containing a second anion; The upper membrane layer is immersed in a mixed solution of the second cation solution and the second anion solution to form a third interface layer; Wherein, the upper film layer is the hole transport layer or the first interface layer, and the second metal cation is selected from Mg. 2+ Ca 2+ Fe 3+ Al 3+ Any one of them, and the second metal cation is selected from Mg 2+ Or Ca 2+ At that time, the second anion was selected from SO4. 2- CO3 2- Or OH - The second metal cation is selected from Fe. 3+ Or Al 3+ When the second anion is OH- - .

16. The preparation method according to claim 15, characterized in that, The solvent for the second cation solution is selected from C1-C8 alcohol solvents, including one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol; and / or, The second metal cation is provided by a solute in the second cation solution, wherein the solute in the second cation solution includes any one of calcium chloride, calcium nitrate, magnesium chloride, magnesium nitrate, ferric chloride, ferric nitrate, aluminum chloride, and aluminum nitrate; and / or, The second anion is provided by a second anion solution, which is an alkaline solution or an alcoholic solution of a salt compound. The alkaline solution includes one or more of an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, and ammonia. The salt compound includes one or more of sodium carbonate, potassium carbonate, sodium sulfate, and potassium sulfate. The alcohol includes C1-C8 alcohol solvents, which include one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, and octanol.

17. A display device, characterized in that, It includes the optoelectronic device as described in any one of claims 1 to 8, or the optoelectronic device prepared by the preparation method as described in any one of claims 9 to 16.

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