Self-assembly hole transport material, application, photoelectric device and preparation method thereof

Abstract

The invention relates to a self-assembled hole transport material, application, a photoelectric device and a preparation method thereof. The self-assembled hole transport material comprises a naphthodithiophene compound and amino siloxane, the structural formula of the naphthodithiophene compound is # imgabs0 #, L is alkylene of C2-C18, and A is an anchoring group. The self-assembled hole transport material is applied to a device, and the efficiency of the device is improved.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic devices, and in particular to a self-assembled hole transport material, application, optoelectronic device and preparation method thereof. Background Art

[0002] In recent years, with the development of perovskite solar cells, the trans-perovskite structure has attracted widespread attention due to its simple preparation and compatibility with large-area production processes. Among the hole transport layers reported for the trans-pin structure, p-type inorganic semiconductors have the advantages of low cost, high transmittance, stable chemical properties and easy large-area preparation. They have been widely used in trans-pin structure perovskite cells. However, p-type inorganic semiconductors have the following problems: low intrinsic conductivity, high defect density, mismatch with the perovskite interface energy level, and reaction with the perovskite precursor, which limit their further development in perovskite cells. In traditional technology, self-assembled monolayers are introduced to modify inorganic semiconductors or directly used as hole transport layers to improve the energy level matching between the hole transport layer and the perovskite interface, promote the extraction and transmission of photogenerated carriers at the interface, and improve the open circuit voltage (Voc) and fill factor (FF) of the device. However, the application of traditional self-assembled monolayer materials in devices still has the problem of low device efficiency. Summary of the invention

[0003] Based on this, some embodiments of the present application provide a self-assembled hole transport material, which can be used in devices to improve device efficiency.

[0004] In addition, some other embodiments of the present application also provide a photoelectric device and a method for preparing the same.

[0005] A self-assembled hole transport material comprises a naphthodithiophene compound and an aminosiloxane, wherein the naphthodithiophene compound has a structural formula of , L is C2~C 18 The alkylene group is A, and A is an anchor group.

[0006] In some embodiments, one or more of the following conditions are met:

[0007] (1) The aminosiloxane includes one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 4-aminobutyltriethoxysilane;

[0008] (2) L is a C2~C6 alkylene group;

[0009] (3) A includes one of a phosphate group and a carboxylic acid group.

[0010] In some embodiments, the mass ratio of the naphthodithiophene compound to the aminosiloxane is (1-10):1; and / or,

[0011] The self-assembled hole transport material comprises and 3-aminopropyltriethoxysilane.

[0012] The application of the self-assembled hole transport material in the preparation of optoelectronic devices.

[0013] A photoelectric device comprises a stacked substrate, a hole transport layer and a perovskite layer, wherein the hole transport layer is arranged between the substrate and the perovskite layer, and the material of the hole transport layer comprises a naphthodithiophene compound and aminosiloxane, wherein the naphthodithiophene compound has a structural formula of , L is C2~C 18 The alkylene group is A, and A is an anchor group.

[0014] In some of the embodiments, the substrate comprises a transparent conductive oxide, the hole transport layer is a single-layer structure comprising a naphthodithiophene compound and aminosiloxane, and the thickness of the hole transport layer is 1 nm to 10 nm.

[0015] In some of the embodiments, the hole transport layer includes a first hole transport sublayer and a second hole transport sublayer stacked together, the first hole transport sublayer is arranged between the substrate and the second hole transport sublayer, the material of the first hole transport sublayer includes an inorganic metal oxide, and the material of the second hole transport sublayer includes a naphthiophene compound and an aminosiloxane.

[0016] In some embodiments, the thickness of the first hole transport sublayer is 10 nm to 50 nm, and the thickness of the second hole transport sublayer is 1 nm to 10 nm; and / or,

[0017] The material of the first hole transport sublayer includes nickel oxide.

[0018] A method for preparing a photoelectric device comprises the following steps:

[0019] forming a hole transport layer on a substrate;

[0020] forming a perovskite layer on the hole transport layer to prepare a photoelectric device;

[0021] The hole transport layer material includes naphthodithiophene compounds and aminosiloxane, and the naphthodithiophene compounds have the structural formula: , L is C2~C 18 The alkylene group is A, and A is an anchor group.

[0022] In some embodiments, the substrate comprises a transparent conductive oxide, and the step of forming a hole transport layer on the substrate comprises:

[0023] A hole transport solution containing a naphthodithiophene compound and aminosiloxane is applied on the substrate, and annealed to anchor the naphthodithiophene compound and the aminosiloxane on the substrate, thereby preparing the hole transport layer.

[0024] In some embodiments, the hole transport layer includes a first hole transport sublayer and a second hole transport sublayer; and the step of forming the hole transport layer on the substrate includes:

[0025] preparing a first hole transport sublayer, wherein the first hole transport sublayer comprises an inorganic metal oxide;

[0026] A second solution containing the naphthodithiophene compound and the aminosiloxane is prepared, the second solution is applied to the first hole transport sublayer, and annealing is performed to anchor the naphthodithiophene compound and the aminosiloxane on the first hole transport sublayer to prepare a second hole transport sublayer.

[0027] The above-mentioned self-assembled hole transport materials include naphthodithiophene compounds and aminosiloxanes. Naphthodithiophene compounds have suitable band gaps and larger dipole moments, and can have excellent hole transport capabilities without affecting the ultraviolet and visible light absorption of the perovskite layer. When combined with aminosiloxanes, they can enhance hole extraction and transfer, strengthen the interaction between the perovskite layer, effectively reduce non-radiative recombination at the interface, and enhance the coverage on the substrate surface, effectively improving the open circuit voltage of the device. Specifically, after mixing naphthodithiophene compounds with aminosiloxanes, the wettability of the perovskite solution on the HTL layer is improved, resulting in a reduction in nanovoids and stress release at the buried interface. And because naphthodithiophene interacts with the terminal amino part in the aminosiloxane molecule (possibly hydrogen bonds), the aminosiloxane molecule can reduce the aggregation of naphthodithiophene and make the distribution of naphthodithiophene uniform, thereby promoting the extraction of carriers and reducing non-radiative recombination at the perovskite interface. The amino groups in aminosiloxane can coordinate with the lead in the perovskite to further passivate the defects in the perovskite layer, thereby effectively improving the filling factor of the device. The anchoring effect of the anchoring groups in the naphthodithiophene compounds and the siloxane double groups in the aminosiloxane significantly improves the carrier extraction and transport at the interface. Therefore, the application of the above self-assembled hole transport material in the device is conducive to further improving the device efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 A schematic diagram of the structure of an optoelectronic device in some embodiments of the present application;

[0030] Figure 2 Another schematic diagram of the structure of the optoelectronic device of some embodiments of the present application;

[0031] Figure 3 A process flow chart of a method for preparing a photoelectric device according to some embodiments of the present application. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below in conjunction with the specific embodiments. The preferred embodiments of the present application are provided in the specific embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0034] Unless otherwise specified or there is a contradiction, the terms and phrases used in this application have the following meanings:

[0035] In this application, "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0036] In the description of the present application, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0037] In this application, "one or several" refers to any one, any two or more of the listed items. Among them, "several" refers to any two or more of the listed items.

[0038] In this application, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0039] In this document, "further", "further", "particularly", "for example", "such as", "example", "for example", etc. are used for descriptive purposes, indicating that the previous and subsequent technical solutions are related in terms of the content covered, but should not be understood as a limitation on the previous technical solution, nor can it be understood as a limitation on the protection scope of this document. In this document, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0040] Herein, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If multiple "optional" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" item is independent of each other. In this application, descriptions such as "optionally contain", "optionally include", etc. mean "contain or not contain". "Optional component X" means that component X exists or does not exist, or means that component X is contained or not contained.

[0041] When a numerical range is disclosed in this application, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed in this application should be understood to include any and all subranges included therein.

[0042] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0043] The terms "including" and "having" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or components that are inherent to these processes, methods, products, or devices.

[0044] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0045] "Alkylene" refers to a hydrocarbon group with two monovalent radical centers derived from an alkyl group by removing a hydrogen atom, which can be a saturated branched alkyl group or a saturated straight chain alkyl group. For example, "C2~C 18 "Alkylene" means that the alkyl portion contains 2 to 18 carbon atoms, and each occurrence can be independently C2 alkylene, C4 alkylene, C5 alkylene, C6 alkylene, C7 alkylene, C8 alkylene, C 10 Alkylene, C 12 Alkylene, C 14 Alkylene, C 16 Alkylene, C 18 Alkylene, etc. Suitable examples include, but are not limited to, 1,1-ethyl (-CH(CH3)-), 1,2-ethyl (-CH2CH2-), 1,1-propyl (-CH(CH2CH3)-), 1,2-propyl (-CH2CH(CH3)-), 1,3-propyl (-CH2CH2CH2-), and 1,4-butyl (-CH2CH2CH2CH2-), etc.

[0046] The names of some abbreviations involved in this article are as follows:

[0047] HTM: hole transport material; HTL: hole transport layer; ETM: electron transport material; ETL: electron transport layer; ITO: conductive glass; PVK: perovskite; PSC: perovskite solar cell; BCP: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0048] The first aspect of the present application provides a self-assembled hole transport material, comprising a naphthodithiophene compound and an aminosiloxane, wherein the naphthodithiophene compound has a structural formula of , L is C2~C 18 The alkylene group is A, and A is an anchoring group.

[0049] The above-mentioned self-assembled hole transport material includes naphthodithiophene compounds and aminosiloxanes. Naphthodithiophene compounds have a suitable band gap and can have excellent hole transport capabilities without affecting the ultraviolet and visible light absorption of the perovskite layer. When combined with aminosiloxanes, they can enhance hole extraction and transfer, strengthen the interaction between the perovskite layer, effectively reduce non-radiative recombination at the interface, and enhance the coverage on the substrate surface, effectively improving the open circuit voltage of the device. Specifically, after mixing naphthodithiophene compounds with aminosiloxanes, the wettability of the perovskite solution on the HTL layer is improved, resulting in a reduction in nanovoids and stress release at the buried interface. And because naphthodithiophene interacts with the terminal amino part in the aminosiloxane molecule (possibly a hydrogen bond), the aminosiloxane molecule can reduce the aggregation of naphthodithiophene and make the distribution of naphthodithiophene uniform, thereby promoting the extraction of carriers and reducing non-radiative recombination at the perovskite interface. The amino groups in aminosiloxane can coordinate with the lead in the perovskite to further passivate the defects in the perovskite layer, thereby effectively improving the filling factor of the device. The anchoring effect of the anchoring groups in the naphthodithiophene compounds and the siloxane double groups in the aminosiloxane significantly improves the carrier extraction and transport at the interface. Therefore, the application of the above self-assembled hole transport material in the device is conducive to further improving the device efficiency.

[0050] In addition, the use of the self-assembled hole transport material as a self-assembled monolayer between the inorganic semiconductor layer and the perovskite layer can effectively prevent the inorganic semiconductor from having unnecessary chemical reactions with the perovskite layer, thereby reducing the interface recombination between the inorganic semiconductor layer and the perovskite layer. It can also improve the crystallization quality of the perovskite crystal, thereby improving the open circuit voltage and fill factor of the device.

[0051] In addition, traditional self-assembled hole transport materials are used in optoelectronic devices, and while improving their open circuit voltage and fill factor, the increase in short-circuit current density is usually ignored. The self-assembled hole transport materials in some embodiments of the present application contain naphthiophene compounds, which have a wider band gap width and a larger dipole moment than traditional self-assembled hole transport materials, and have a better hole transport mode. When combined with aminosiloxane and used in optoelectronic devices, they can increase the short-circuit current density while improving their open circuit voltage and fill factor, thereby further helping to improve device efficiency.

[0052] It can be understood that in some other embodiments, the self-assembled hole transport material can also be directly used as a hole transport layer, applied between the substrate and the perovskite layer, which is also beneficial to improving device efficiency compared with traditional self-assembled single molecule materials.

[0053] In some embodiments, the aminosilicone includes one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 4-aminobutyltriethoxysilane. In some embodiments, the aminosilicone includes one or more of 3-aminopropyltriethoxysilane and 4-aminobutyltriethoxysilane.

[0054] In some embodiments, L is a C2-C6 alkylene group. In a specific example, L is selected from one or more of ethylene, propylene, butylene, pentylene and hexylene. In some embodiments, L is selected from a linear C2-C6 alkylene group.

[0055] In some embodiments, A includes one of a phosphate group and a carboxylic acid group. In a specific example, A includes a phosphate group. The P=O double bond in the phosphate group can coordinate with free iodine to passivate the lead vacancies in the perovskite layer, and the amino group in the aminosiloxane can coordinate with the lead in the perovskite, and the two cooperate to further passivate the defects in the perovskite layer, thereby effectively improving the fill factor of the device and further improving the device efficiency.

[0056] In some embodiments, the structural formula of the naphthodithiophene compound is selected from one or more of the following: , and .

[0057] In some embodiments, the self-assembled hole transport material comprises and 3-aminopropyltriethoxysilane.

[0058] In some embodiments, the mass ratio of the naphthodithiophene compound to the aminosiloxane is (1-10):1. For example, the mass ratio of the naphthodithiophene compound to the aminosiloxane may be, but is not limited to, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or a range consisting of any two of these values. Optionally, the mass ratio of the naphthodithiophene compound to the aminosiloxane is (1-5):1. Optimizing the mass ratio of the naphthodithiophene compound to the aminosiloxane is beneficial to further improve the photoelectric performance of the device.

[0059] Furthermore, the self-assembled hole transport material includes a mass ratio of (1-10):1 and 3-aminopropyltriethoxysilane ( ).

[0060] In some embodiments, the synthesis route of naphthodithiophene compounds is as follows: .

[0061] The preparation steps are as follows:

[0062] Step S110: Naphtho[1,2-B:5,6-B']dithiophene and X1-C(=O)-C n H 2n+1 -X2 reaction to generate intermediate 1.

[0063] Among them, the structural formula of naphtho[1,2-B:5,6-B']dithiophene is The structural formula of intermediate 1 is , X1 and X2 are each independently halogen. For example, X1 is F, Cl, Br, etc., and X2 is F, Cl, Br, etc. In one embodiment, X1 is Cl, X2 is Br, X1-C(=O)-C n H 2n+1 -X2 is Cl-C(=O)-C n H 2n+1 -Br. n is an integer of 1 to 17.

[0064] In some embodiments, a catalyst is also added in step S110. The catalyst may be, for example but not limited to, aluminum chloride.

[0065] In some embodiments, step S110 is performed at -20°C to -70°C, and the reaction time is 4 hours.

[0066] In a specific example, naphtho[1,2-B:5,6-B']dithiophene is mixed with a catalyst at -20°C, cooled to -70°C, and X1-C(=O)-C is added. n H2 n+1 -X2, continue the reaction for 4 hours. After the reaction is completed, extract, wash and dry.

[0067] Step S120: reducing the carbonyl group in intermediate 1 to a methylene group to generate intermediate 2.

[0068] Among them, the structural formula of intermediate 2 is Specifically, the reduction system used in step S120 includes borane tetrahydrofuran complex (BH3﹒THF) and boron trifluoride etherate (BF3﹒Et2O).

[0069] Specifically, step S120 includes: mixing the intermediate 1 with borane tetrahydrofuran complex (BH3.THF) and boron trifluoride etherate for reaction for 24 hours.

[0070] It can be understood that the above only provides a method for reducing the carbonyl group in the intermediate 1 to a methylene group, but is not limited thereto, and other common methods in the art can also be used.

[0071] Step S130: reacting the intermediate 2 with the ester of the anchoring group to prepare a naphthodithiophene compound.

[0072] In some embodiments, the anchoring group is a phosphate group, and the step of reacting the intermediate 2 with the ester of the anchoring group includes: reacting the intermediate 2 with a trialkyl phosphite at 150° C. to 170° C. for 12 h to 24 h, stirring the reaction product with a silane halide in 1,4-dioxane for 24 h to 48 h, adding methanol and water, and continuing the reaction for 6 h to 24 h to hydrolyze it to prepare a naphthiophene compound.

[0073] Specifically, the trialkyl phosphite includes, but is not limited to, triethyl phosphite.

[0074] Specifically, the halogenated silane includes one or more of trimethylbromosilane, trimethylchlorosilane and triethylbromosilane.

[0075] In some other embodiments, the anchoring group is a carboxylic acid group, and the intermediate 2 is reacted with an ester of the anchoring group. The hydrolysis step includes: reacting the intermediate 2 with a halogenated carboxylic acid ester, and then hydrolyzing to generate a naphthodithiophene compound.

[0076] The second aspect of the present application provides a use of the above-mentioned self-assembled hole transport material in the preparation of optoelectronic devices.

[0077] The third aspect of the present application provides a photoelectric device, comprising a substrate, a hole transport layer and a perovskite layer arranged in layers, wherein the hole transport layer is arranged between the substrate and the perovskite layer, and the material of the hole transport layer comprises a naphthodithiophene compound and an aminosiloxane, wherein the naphthodithiophene compound has a structural formula of , L is C2~C 18 The alkylene group is A, and A is an anchor group.

[0078] In some embodiments, the substrate includes a transparent conductive oxide, the hole transport layer is a single-layer structure including a naphthodithiophene compound and an aminosiloxane, and the thickness of the hole transport layer is 1 nm to 10 nm. For example, the thickness of the hole transport layer can be, but is not limited to, 1 nm, 2 nm, 4 nm, 5 nm, 6 nm, 8 nm, 9 nm, 10 nm, or a range consisting of any two of these values. Specifically, the naphthodithiophene compound and the aminosiloxane are anchored on the substrate.

[0079] In some other embodiments, the hole transport layer includes a first hole transport sublayer and a second hole transport sublayer, the first hole transport sublayer is disposed between a substrate and the second hole transport sublayer, the material of the first hole transport sublayer includes an inorganic metal oxide, and the material of the second hole transport sublayer includes a naphthodithiophene compound and an aminosiloxane. Specifically, the naphthodithiophene compound and the aminosiloxane are anchored on the first hole transport sublayer.

[0080] Specifically, the thickness of the first hole transport sublayer is 10nm to 50nm, and the thickness of the second hole transport sublayer is 1nm to 10nm. For example, the thickness of the first hole transport sublayer may be, but is not limited to, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, or a range consisting of any two of these values. The thickness of the second hole transport sublayer may be, but is not limited to, 1nm, 2nm, 4nm, 5nm, 6nm, 8nm, 9nm, 10nm, or a range consisting of any two of these values.

[0081] Specifically, the material of the first hole transport sublayer includes nickel oxide.

[0082] In some embodiments, the base includes a substrate and a transparent conductive oxide disposed on the substrate. The substrate may be, for example, but not limited to, glass. The transparent conductive oxide may be, but not limited to, one or more of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), indium-doped zinc oxide (IZO), fluorine-doped tin oxide (FTO), indium tungsten oxide (IWO), indium cerium oxide (ICO), and the like.

[0083] In some embodiments, the material of the perovskite layer includes an ABX3 type perovskite material, wherein the A ions include one or more of cesium ions, rubidium ions, potassium ions, methylamine ions, formamidinium ions, methylenediamine ions, benzamidinium cations, and guanidinium cations, the B ions include one or more of divalent lead ions and divalent tin ions, and the X ions include one or more of fluoride ions, chloride ions, bromide ions, iodide ions, thiocyanate ions, tetrafluoroborate ions, hexafluorophosphate ions, formate ions, and acetate ions.

[0084] In some embodiments, the photoelectric device further comprises an electron transport layer, a hole blocking layer and a counter electrode arranged on a side of the perovskite layer away from the substrate, the hole blocking layer is arranged between the electron transport layer and the counter electrode, and the electron transport layer is closer to the perovskite layer than the counter electrode.

[0085] Specifically, the material of the electron transport layer includes one or more of fullerene and fullerene derivatives.

[0086] Specifically, the material of the counter electrode is selected from one or more of silver, copper, conductive oxide and carbon electrode.

[0087] Specifically, the material of the hole blocking layer includes one or more of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and zirconium acetylacetonate.

[0088] In some embodiments, see Figure 1The optoelectronic device includes a stacked substrate 110, a first hole transport sublayer 122, a second hole transport sublayer 124, a perovskite layer 130, an electron transport layer 140, a hole blocking layer 150 and a counter electrode 160. The first hole transport sublayer 122 and the second hole transport sublayer 124 constitute the hole transport layer 120.

[0089] In some other embodiments, see Figure 2 The photoelectric device 200 includes a stacked substrate 210, a hole transport layer 220, a perovskite layer 230, an electron transport layer 240, a hole blocking layer 250 and a counter electrode 260. The hole transport layer 220 is a single-layer structure including a naphthodithiophene compound and aminosiloxane.

[0090] A fourth aspect of the present application provides a method for preparing a photoelectric device, comprising the following steps:

[0091] forming a hole transport layer on a substrate;

[0092] forming a perovskite layer on the hole transport layer to prepare a photoelectric device;

[0093] The hole transport layer material includes naphthodithiophene compounds and aminosiloxane, and the naphthodithiophene compounds have the structural formula: , L is C2~C 18 The alkylene group is A, and A is an anchoring group.

[0094] In some embodiments, the substrate comprises a transparent conductive oxide, and the step of forming a hole transport layer on the substrate comprises:

[0095] A hole transport solution containing a naphthodithiophene compound and aminosiloxane is applied on the substrate, and annealed to anchor the naphthodithiophene compound and the aminosiloxane on the substrate, thereby preparing the hole transport layer.

[0096] Specifically, the solvent used in the hole transport solution includes anhydrous ethanol.

[0097] Specifically, in the step of preparing the hole transport layer, heating annealing is performed at 100° C. to 150° C. for 5 min to 30 min.

[0098] Specifically, naphthodithiophene compounds and aminosiloxane are dissolved in anhydrous ethanol to prepare a hole transport solution, which is dropped onto a substrate, spin coated at 5000 rpm for 30 seconds, and heated and annealed at 100° C. to 150° C. for 5 to 30 minutes to obtain a hole transport layer.

[0099] In some other embodiments, the hole transport layer includes a first hole transport sublayer and a second hole transport sublayer; and the step of forming the hole transport layer on the substrate includes:

[0100] preparing a first hole transport sublayer, wherein the first hole transport sublayer comprises an inorganic metal oxide;

[0101] A second solution containing the naphthodithiophene compound and the aminosiloxane is prepared, the second solution is applied to the first hole transport sublayer, and annealing is performed to anchor the naphthodithiophene compound and the aminosiloxane on the first hole transport sublayer to prepare a second hole transport sublayer.

[0102] Specifically, the thickness of the first hole transport sublayer is 10 nm to 50 nm, and the thickness of the second hole transport sublayer is 1 nm to 10 nm.

[0103] Specifically, the solvent used in the first solution includes water.

[0104] Specifically, in the step of preparing the first hole transport sublayer, annealing is performed at 130°C to 200°C for 15 min to 30 min. Specifically, an inorganic metal oxide is dispersed in water to prepare a first solution, the first solution is dropped onto the substrate, spin-coated at a speed of 3000 rpm for 30 s, and annealed at 130°C to 200°C for 15 min to 30 min to prepare the first hole transport sublayer.

[0105] Specifically, the solvent used in the second solution includes anhydrous ethanol.

[0106] Specifically, in the step of preparing the second hole transport sublayer, heating annealing is performed at 100° C. to 150° C. for 5 min to 30 min.

[0107] Specifically, naphthodithiophene compounds and aminosiloxane are dissolved in anhydrous ethanol to prepare a second solution, the second solution is dropped onto the first hole transport sublayer, spin coated at 5000 rpm for 30 seconds, and heated and annealed at 100° C. to 150° C. for 5 min to 30 min to obtain the second hole transport sublayer.

[0108] In some embodiments, a solution method is used to prepare a perovskite layer. Specifically, the steps of preparing the perovskite layer include: preparing a perovskite precursor solution, spin coating the perovskite precursor solution on the surface of the hole transport layer, annealing, and preparing the perovskite layer. It can be understood that the specific perovskite precursor solution, spin coating process, and annealing process can be commonly used in the art. For example, the spin coating step can be, but is not limited to, first spin coating at a speed of 1000 rpm for 10s, then spin coating at a speed of 5000 rpm for 30s, and the annealing process is annealing at 100°C for 40min.

[0109] In some embodiments, the photoelectric device further comprises an electron transport layer, a hole blocking layer and a counter electrode arranged on a side of the perovskite layer away from the substrate, the hole blocking layer is arranged between the electron transport layer and the counter electrode, and the electron transport layer is closer to the perovskite layer than the counter electrode.

[0110] In one embodiment, the electron transport layer is prepared by a solution method. Specifically, the preparation step of the electron transport layer includes: preparing a solution containing an electron transport material, coating it on the perovskite layer, and preparing the electron transport layer. For example, the electron transport material is dissolved in chlorobenzene to a concentration of 20 mg / mL, and the obtained electron transport material solution is dripped on the perovskite layer, and spin-coated at a speed of 3000 rpm for 60 seconds to prepare the electron transport layer. In another embodiment, the electron transport layer is prepared by evaporation.

[0111] In one embodiment, the hole blocking layer is prepared by a solution method. Specifically, the preparation step of the hole blocking layer includes: coating a solution containing a hole blocking material on the electron transport layer to prepare the hole blocking layer. For example, the hole blocking material is dissolved in isopropanol to a concentration of 0.5 mg / mL, and the obtained hole blocking material solution is dripped on the electron transport layer, and spin-coated at a speed of 5000 rpm for 35 seconds to prepare the hole blocking layer. In another embodiment, the hole blocking layer is prepared by an evaporation method.

[0112] Specifically, the counter electrode is prepared by an evaporation method.

[0113] In some embodiments, see Figure 3 , the preparation method of the optoelectronic device comprises the following steps:

[0114] Step S310: preparing a first solution containing an inorganic metal oxide, applying the first solution on a substrate, and annealing to prepare a first hole transport sublayer.

[0115] Step S320: preparing a second solution containing a naphthodithiophene compound and aminosiloxane, applying the second solution on the first hole transport sublayer, and annealing to prepare a second hole transport sublayer.

[0116] Step S330: applying a perovskite precursor solution onto the second hole transport sublayer to prepare a perovskite layer.

[0117] Step S340: forming an electron transport layer on the perovskite layer.

[0118] Step S350: forming a hole blocking layer on the electron transport layer.

[0119] Step S360: forming a counter electrode on the hole blocking layer to prepare a photoelectric device.

[0120] It is understood that the above only provides a more specific method for preparing an optoelectronic device, but is not limited thereto. For example, in some other embodiments, step S310 can be omitted, and a solution containing naphthodithiophene compounds and aminosiloxane can be directly applied to the substrate to prepare a hole transport layer.

[0121] Figure 3 This is a schematic diagram of a method for preparing a photoelectric device according to an embodiment of the present application. It should be understood that although Figure 3 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and they can be performed in other orders. Figure 3 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The order of execution is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of other sub-steps or stages.

[0122] In order to make the purpose and advantages of the present application clearer, the self-assembled hole transport material of the present application and its effect are further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and shall not be used to limit the present application. The following embodiments do not include other components except inevitable impurities unless otherwise specified. The drugs and instruments used in the embodiments are conventionally selected in the art unless otherwise specified. The experimental methods for which specific conditions are not specified in the embodiments are implemented according to conventional conditions, such as the conditions described in the literature, books, or methods recommended by the manufacturer.

[0123] Example 1

[0124] This embodiment provides a naphthodithiophene compound, and its synthesis route is as follows:

[0125] , the preparation steps are as follows:

[0126] (1) Naphtho[1,2-B:5,6-B']dithiophene (2 g, 8.32 mmol) was stirred in dichloromethane (200 mL) and cooled to -20°C, and aluminum chloride (3.9 g, 29.47 mmol) was added thereto. The reaction system was cooled to -70°C, 4-bromobutyryl chloride (6 g, 32.78 mmol) was added dropwise over 15 min, stirred at room temperature for 4 h, extracted with 100 mL of water and 150 mL of dichloromethane, the organic layer was separated, washed with water (2×100 mL) and brine (200 mL), and dried over anhydrous magnesium sulfate. The obtained solid was first recrystallized from toluene, and then purified and separated by column chromatography on a silica gel column using toluene as the eluent to obtain intermediate 1 (mass 1.1 g, yield 34%).

[0127] (2) The obtained intermediate 1 (1.1 g, 2.83 mmol) was added to a reaction flask, and borane tetrahydrofuran complex (BH3﹒THF, 4 mL) was slowly added dropwise, and then boron trifluoride etherate (BF3﹒Et2O, 0.5 M, 6 mL) was added dropwise with stirring. After the addition was completed, the mixture was stirred at room temperature for 24 hours. After the reaction was completed, the reaction solution was extracted with saturated sodium carbonate solution and brine, and the organic phase was collected, concentrated in vacuo, and purified by column chromatography using dichloromethane as an eluent to obtain intermediate 2 (mass 1.0 g, yield 95%).

[0128] (3) The obtained intermediate 2 (1.0 g, 2.68 mmol) was dissolved in triethyl phosphite (20 mL) and reacted at 160°C for 16 hours. After the reaction was completed, the mixture was dried under vacuum. The obtained viscous liquid was dissolved in 1,4-dioxane (20 mL) and trimethylsilyl bromide (TMSBr, 5 mL) was added dropwise and stirred at room temperature for 24 hours. After the reaction was completed, the reaction solution was concentrated under vacuum and methanol (10 mL) was added to dissolve the mixture. 5 mL of deionized water was slowly added dropwise. After solids precipitated, the mixture was filtered and the filter cake was washed with ether and dried under vacuum to obtain the product 4Pz-NDP (mass 0.75 g, yield 75%).

[0129] The product 4Pz-NDP is characterized as follows:

[0130] 1H NMR (500 MHz, DMSO-d6) δ 7.94 (d, J = 4.8 Hz, 3H), 7.92 (s, 1H), 7.87 (dd, J = 7.3, 1.9 Hz, 1H), 7.83 (dd, J = 7.4, 1.1 Hz, 1H), 7.50 (d, J =5.3 Hz, 1H), 7.42 (dd, J = 5.4, 1.2 Hz, 1H), 7.24 (d, J = 1.9 Hz, 1H), 2.76(t, J = 6.3 Hz, 2H), 2.06 – 1.89 (m, 2H), 1.77 (pd, J = 6.3, 0.9 Hz, 2H),1.73 – 1.65 (m, 2H).

[0131] 13 C NMR (125 MHz, DMSO-d6) δ 144.47, 137.96, 135.06, 134.75, 129.57,129.43, 125.98, 124.97, 124.41, 123.93, 123.78, 123.54, 123.26, 34.26, 34.22,30.03, 29.95, 26.57, 25.80, 22.52, 22.46.

[0132] EI-HRMS: calcd. for [M] + :376.0357. Found: 376.0361.

[0133] Example 2

[0134] This embodiment provides a perovskite solar cell, and the preparation steps are as follows:

[0135] (1) The ITO conductive glass was ultrasonically cleaned with deionized water, acetone and isopropanol for 15 min respectively, and finally dried in a drying oven at 75°C. The dried ITO conductive glass was treated in a UV ozone machine for 5 min to remove organic impurities on its surface and optimize its surface wettability.

[0136] (2) Dissolve 21.81 g (75 mmol) of nickel nitrate hexahydrate in 15 mL of deionized water, stir and dissolve to obtain a 5 mol / L nickel nitrate solution, then add sodium hydroxide aqueous solution (2 mol / L) dropwise until the pH value of the solution is about 9-10, and continue stirring for 15 min after the addition is completed. Filter through a suction filtration device to retain the solid product, that is, obtain nickel hydroxide colloid, then wash the obtained nickel hydroxide colloid with deionized water and filter again, and repeat this process three times. Then heat the filter cake in an oven at 80 ° C for 6 h. Finally, place the dried solid in a muffle furnace and calcine at 300 ° C for 2 h. After calcination, naturally cool to room temperature to obtain black nickel oxide nanoparticles (NiOx). The prepared nickel oxide nanoparticles were dispersed in deionized water with a dispersion concentration of 20 mg / mL. The NiOx dispersion was placed in an ultrasonic cleaner for ultrasonic vibration for 5 minutes to obtain a uniform dispersion. The NiOx dispersion was then spin-coated on the surface of the ITO conductive glass at a speed of 3000 rpm for 30 seconds. After the spin coating was completed, it was heated and annealed at 130°C for 15 minutes to obtain the first hole transport sublayer.

[0137] (3) Dissolve 3 mg of 4Pz-NDP prepared in Example 1 in 1 mL of anhydrous ethanol to obtain a 4Pz-NDP solution. Dissolve 2 mg of 3-aminopropyltriethoxysilane (APTS) in 1 mL of anhydrous ethanol to obtain an APTS solution. Mix the two in a volume ratio of 3:1 to obtain a mixed self-assembled molecular solution. Take 60 µL of the mixed self-assembled molecular solution, add it dropwise on the first hole transport sublayer, spin coat it at 5000 rpm for 30 seconds, and heat anneal at 100°C for 10 minutes. Spin coat the ethanol solvent again to clean and remove the excess self-assembled molecule (SAM) material that is not covalently bonded to NiOx, and the second hole transport sublayer can be formed.

[0138] (4) Dissolve 722.08 mg of lead iodide and 238.50 mg of iodomethylamine solid in 1 mL of N,N-dimethylformamide (DMF) and stir at room temperature until completely dissolved to obtain a perovskite precursor solution. In a nitrogen glove box, take 30 µL of the perovskite precursor solution and drop it onto the second hole transport sublayer. First, spin coat it at 1000 rpm for 10 seconds, then spin coat it at 5000 rpm for 30 seconds. After 25 seconds of spin coating, quickly drop 125 µL of chlorobenzene, then place the ITO conductive glass on a hot plate and heat and anneal it at 100 °C for 40 minutes to form a perovskite layer.

[0139] (5) Transfer the ITO conductive glass prepared with the first hole transport layer, the second hole transport layer and the perovskite light absorbing layer to the vacuum coating instrument and wait until the vacuum degree is drawn to 3*10 -4At 1400 Å Pa, a C60 electron transport layer with a thickness of 25 nm, a BCP hole blocking layer with a thickness of 6 nm, and an Ag electrode film with a thickness of 100 nm were respectively deposited by vapor deposition to obtain the perovskite solar cell of this embodiment.

[0140] Example 3

[0141] This embodiment provides a perovskite solar cell, and the preparation steps are similar to those of Embodiment 2, except that the first hole transport sublayer is not included. The other steps are similar to those of Embodiment 2 and will not be described in detail.

[0142] Example 4

[0143] This embodiment provides a perovskite solar cell, and the preparation steps are similar to those of Embodiment 2, except that: in the second hole transport sublayer, the mass ratio of the naphthodithiophene compound and 3-aminopropyltriethoxysilane is different. In this embodiment, the mass ratio of the two is 3: 1. The other steps are similar to those of Embodiment 2 and will not be repeated.

[0144] Example 5

[0145] This embodiment provides a perovskite solar cell, and the preparation steps are similar to those of Embodiment 2, except that: in the second hole transport sublayer, the mass ratio of the naphthodithiophene compound and 3-aminopropyltriethoxysilane is different. In this embodiment, the mass ratio of the two is 5: 1. The other steps are similar to those of Embodiment 2 and will not be repeated.

[0146] Example 6

[0147] This embodiment provides a perovskite solar cell, and the preparation steps are similar to those of Embodiment 2, except that: in the second hole transport sublayer, the mass ratio of the naphthodithiophene compound and 3-aminopropyltriethoxysilane is different. In this embodiment, the mass ratio of the two is 8: 1. The other steps are similar to those of Embodiment 2 and will not be repeated.

[0148] Example 7

[0149] This embodiment provides a perovskite solar cell, and the preparation steps are similar to those of Embodiment 2, except that: in the second hole transport sublayer, the aminosilane is different, and in this embodiment, the aminosilane is 4-aminobutyltriethoxysilane. The other steps are similar to those of Embodiment 2 and will not be repeated.

[0150] Example 8

[0151] This embodiment provides a perovskite solar cell, and the preparation steps are similar to those of Embodiment 2, except that: in the second hole transport sublayer, the naphthodithiophene compound is different. In this embodiment, the naphthodithiophene compound is The other steps are similar to those in Example 2 and will not be described in detail.

[0152] Example 9

[0153] This embodiment provides a perovskite solar cell, and the preparation steps are similar to those of Embodiment 2, except that: in the second hole transport sublayer, the naphthodithiophene compound is different. In this embodiment, the naphthodithiophene compound is The other steps are similar to those in Example 2 and will not be described in detail.

[0154] Comparative Example 1

[0155] Comparative Example 1 provides a perovskite solar cell, and the preparation steps are similar to those of Example 2, except that the second hole transport sublayer is not included. The other steps are similar to those of Example 2 and will not be described in detail.

[0156] Comparative Example 2

[0157] Comparative Example 2 provides a perovskite solar cell, and the preparation steps are similar to those of Example 2, except that the second hole transport sublayer contains only 4Pz-NDP. The other steps are similar to those of Example 2 and will not be described in detail.

[0158] Comparative Example 3

[0159] Comparative Example 3 provides a perovskite solar cell, and the preparation steps are similar to those of Example 3, except that the second hole transport sublayer contains only 4Pz-NDP. The other steps are similar to those of Example 3 and will not be described in detail.

[0160] Table 1 Performance tests of various embodiments and comparative examples

[0161]

[0162] It can be seen from Table 1 above that the use of naphthodithiophene compounds and aminosiloxane as self-assembled hole transport materials in perovskite solar cells is beneficial to improving the short-circuit current density while improving the open circuit voltage and fill factor of the device, thereby helping to improve the device efficiency.

[0163] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0164] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the contents of the attached claims, and the description and drawings can be used to explain the contents of the claims.

Claims

1. A self-assembled hole transport material, characterized in that: It includes naphthodithiophene compounds and aminosiloxane, wherein the naphthodithiophene compounds have the structural formula: , L is C2~C 18 The alkylene group is A, and A is an anchoring group.

2. The self-assembled hole transport material according to claim 1, characterized in that: Meet one or more of the following conditions: (1) The aminosiloxane includes one or more of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 4-aminobutyltriethoxysilane; (2) L is a C2~C6 alkylene group; (3) A includes one of a phosphate group and a carboxylic acid group.

3. The self-assembled hole transport material according to claim 1 or 2, characterized in that: The mass ratio of the naphthodithiophene compound to the aminosiloxane is (1-10):1; and / or, The self-assembled hole transport material comprises and 3-aminopropyltriethoxysilane.

4. Use of the self-assembled hole transport material according to any one of claims 1 to 3 in the preparation of optoelectronic devices.

5. A photoelectric device, characterized in that: The invention comprises a stacked substrate, a hole transport layer and a perovskite layer, wherein the hole transport layer is arranged between the substrate and the perovskite layer, and the material of the hole transport layer comprises a naphthodithiophene compound and aminosiloxane, and the naphthodithiophene compound has a structural formula of , L is C2~C 18 The alkylene group is A, and A is an anchoring group.

6. The optoelectronic device according to claim 5, characterized in that: The substrate comprises a transparent conductive oxide, the hole transport layer is a single-layer structure comprising a naphthodithiophene compound and aminosiloxane, and the thickness of the hole transport layer is 1 nm to 10 nm.

7. The optoelectronic device according to claim 5, characterized in that: The hole transport layer includes a first hole transport sublayer and a second hole transport sublayer stacked together, wherein the first hole transport sublayer is arranged between the substrate and the second hole transport sublayer, the material of the first hole transport sublayer includes an inorganic metal oxide, and the material of the second hole transport sublayer includes a naphthodithiophene compound and aminosiloxane.

8. The optoelectronic device according to claim 7, characterized in that: The thickness of the first hole transport sublayer is 10 nm to 50 nm, and the thickness of the second hole transport sublayer is 1 nm to 10 nm; and / or, The material of the first hole transport sublayer includes nickel oxide.

9. A method for preparing a photoelectric device, characterized in that: The steps include: forming a hole transport layer on a substrate; forming a perovskite layer on the hole transport layer to prepare a photoelectric device; The hole transport layer material includes naphthodithiophene compounds and aminosiloxane, and the naphthodithiophene compounds have the structural formula: , L is C2~C 18 The alkylene group is A, and A is an anchoring group.

10. The method for preparing a photoelectric device according to claim 9, characterized in that: The substrate includes a transparent conductive oxide, and the step of forming a hole transport layer on the substrate includes: A hole transport solution containing a naphthodithiophene compound and aminosiloxane is applied on the substrate, and annealed to anchor the naphthodithiophene compound and the aminosiloxane on the substrate, thereby preparing the hole transport layer.

11. The method for preparing a photoelectric device according to claim 9, characterized in that: The hole transport layer includes a first hole transport sublayer and a second hole transport sublayer; the step of forming the hole transport layer on the substrate includes: preparing a first hole transport sublayer, wherein the first hole transport sublayer comprises an inorganic metal oxide; A second solution containing the naphthodithiophene compound and the aminosiloxane is prepared, the second solution is applied to the first hole transport sublayer, and annealing is performed to anchor the naphthodithiophene compound and the aminosiloxane on the first hole transport sublayer to prepare a second hole transport sublayer.

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