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

Abstract

The invention relates to a self-assembled hole transport material, a photoelectric device and a preparation method and application thereof. The self-assembled hole transport material has the following structural general formula: # imgabs0 #, in the formula, each L is independently a C2-C18 alkylene group; each A is independently an anchoring group; each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, sulfydryl, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl; and m is an integer of 1-4. The self-assembled hole transport material is beneficial to improving the film forming uniformity, improving the wettability of the perovskite layer, and further improving the efficiency of the device.

Description

Technical Field

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

[0002] Perovskite solar cells (PSCs) have attracted extensive attention in recent years as an efficient and low-cost alternative to traditional solar energy conversion. As one of the important components of perovskite solar cells, the hole transport layer plays a key role in passivating interface defects, energy level matching, hole extraction process, and non-radiative recombination suppression.

[0003] At present, self-assembled monolayers (SAMs) materials represented by 2PACz and 4PACz rely on forming a self-assembled monolayer (SAM) on a metal oxide substrate to extract holes. They have many advantages such as simple process, low cost, and low usage, and have become the first choice for preparing efficient and stable hole transport materials in inverse perovskite solar cells. However, traditional self-assembled monolayers still have problems such as poor film uniformity and poor wettability of the perovskite layer on the self-assembled monolayer, which is not conducive to the high-quality growth of perovskite crystals and seriously affects the performance of the device. Summary of the invention

[0004] Based on this, some embodiments of the present application provide a self-assembled hole transport material, which is beneficial to improving the uniformity of film formation and the wettability of perovskite on the self-assembled hole transport material.

[0005] In addition, other embodiments of the present application also provide a preparation method, application, optoelectronic device and preparation method thereof of a self-assembled hole transport material.

[0006] A self-assembled hole transport material having the following general structural formula:

[0007] ;

[0008] In the formula, each L is independently C2~C 18 of alkylene;

[0009] Each A is independently an anchoring group;

[0010] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0011] m is an integer from 1 to 4.

[0012] In some embodiments, one or more of the following conditions are met:

[0013] (1) Each L is independently a C2-C6 alkylene group;

[0014] (2) Each A is independently selected from a phosphate group, a sulfonate group, a carboxylate group and a borate group;

[0015] (3) Each R is independently selected from one of hydrogen, C1~C6 alkyl and C1~C6 alkoxy; optionally, each R is independently selected from one of hydrogen, methyl and methoxy.

[0016] In some embodiments, the self-assembled hole transport material is selected from one or more of the following structures:

[0017] , , , , and .

[0018] A method for preparing a self-assembled hole transport material comprises the following steps:

[0019] Providing compound a;

[0020] The compound a is reacted with XLX to generate compound b;

[0021] reacting the compound b with the ester of the anchoring group to generate a self-assembled hole transport material;

[0022] Wherein, the structural formula of the compound a is , the structural formula of the compound b is , the structural formula of the self-assembled hole transport material is ;

[0023] Wherein, each L is independently C2~C 18 of alkylene;

[0024] Each A is independently an anchoring group;

[0025] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0026] m is an integer from 1 to 4;

[0027] X is halogen.

[0028] In some embodiments, the compound a is prepared by the following steps:

[0029] Compound c and compound d are subjected to Suzuki reaction to generate compound e;

[0030] The compound e is subjected to a cyclization reaction under the action of triethyl phosphite to generate the compound a;

[0031] Wherein, the structural formulas of the compound c, the compound d and the compound e are respectively , and , Y is halogen.

[0032] Application of the self-assembled hole transport material as described above or the self-assembled hole transport material prepared by the above preparation method in the preparation of optoelectronic devices.

[0033] A photoelectric device comprises a substrate, a hole transport layer and a perovskite layer, wherein the substrate comprises a metal oxide, and the hole transport layer is disposed between the substrate and the perovskite layer;

[0034] The material of the hole transport layer includes a self-assembled hole transport material having the following general structural formula:

[0035] ;

[0036] In the formula, each L is independently C2~C 18 of alkylene;

[0037] Each A is independently an anchoring group;

[0038] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0039] m is an integer from 1 to 4.

[0040] In some embodiments, the hole transport layer is a single-layer structure including the self-assembled hole transport material, and the self-assembled hole transport material is anchored on the substrate;

[0041] Alternatively, the hole transport layer includes a first sublayer and a second sublayer which are stacked, the material of the first sublayer is a metal oxide, the material of the second sublayer includes the self-assembled hole transport material, the first sublayer is arranged between the substrate and the second sublayer, and the self-assembled hole transport material is anchored on the first sublayer.

[0042] 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.

[0043] A method for preparing a photoelectric device comprises the following steps:

[0044] forming a hole transport layer on a substrate;

[0045] forming a perovskite layer on the hole transport layer to prepare a photoelectric device;

[0046] Wherein, the substrate comprises a metal oxide, and the material of the hole transport layer comprises a self-assembled hole transport material having the following general structural formula:

[0047] ;

[0048] In the formula, each L is independently C2~C 18 of alkylene;

[0049] Each A is independently an anchoring group;

[0050] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0051] m is an integer from 1 to 4.

[0052] In some embodiments, the preparation steps of the hole transport layer include:

[0053] dissolving the self-assembled hole transport material in tetrahydrofuran to obtain a hole transport solution;

[0054] The hole transport solution is applied on the surface of the substrate, and annealed at 100° C. to 150° C. for 5 min to 20 min to anchor the self-assembled hole transport material on the substrate to prepare a hole transport layer.

[0055] The self-assembled hole transport material is based on the unique structure of tricarbazole phosphorus oxide, which not only retains the appropriate energy level characteristics of carbazole, but also connects the tricarbazole group through the phosphorus oxide group, reduces the degree of conjugation of the molecule, and makes the molecule have a twisted structure. The non-conjugated, twistable connection structure can inhibit the π-π stacking between molecules, so that the self-assembled hole transport material has better dynamic adaptability during the film formation process and improves the uniformity of the film. In addition, the twisted molecular structure allows part of the anchoring group to be anchored on the surface of the metal oxide substrate, and the other part of the anchoring group is located at the leaving end of the substrate, which is conducive to improving the wettability of the perovskite on the hole transport layer and improving the crystal quality of the perovskite layer. And the phosphorus oxygen group can form an adduct by reacting with the Lewis acid-base of the B-site atom such as the lead atom on the perovskite layer, thereby regulating the crystallization of the perovskite and reducing the defects in the perovskite film. Therefore, the self-assembled hole transport material is conducive to improving the uniformity of film formation, improving the wettability of the perovskite layer, and thus improving the efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] 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.

[0057] Figure 1 A schematic diagram of the process flow of a method for preparing a self-assembled hole transport material according to some embodiments of the present application;

[0058] Figure 2 A schematic diagram of the structure of an optoelectronic device according to some embodiments of the present application. DETAILED DESCRIPTION

[0059] 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.

[0060] 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.

[0061] Unless otherwise specified or there is a contradiction, the terms and phrases used in this application have the following meanings:

[0062] 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.

[0063] In the description of the present application, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0064] 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.

[0065] 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.

[0066] The words "optionally" and the like in this application refer to embodiments of the present application that may provide certain beneficial effects in certain cases. However, other embodiments may also be optional under the same or other circumstances. In addition, the statement of one or more optional embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] The term "alkyl" refers to a saturated hydrocarbon containing primary (normal) carbon atoms, or secondary carbon atoms, or tertiary carbon atoms, or quaternary carbon atoms, or a combination thereof. It is understood that alkyl includes straight chain alkyl and branched chain alkyl. Phrases containing this term, for example, "C1-C6 alkyl" refers to an alkyl containing 1 to 6 carbon atoms, and each occurrence may be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl. Suitable examples include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -C H(CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl -1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl ( -CH(CH3)CH(CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3.

[0073] "Halogen" or "halo" refers to F, Cl, Br or I.

[0074] "Alkoxy" refers to a group with -O-alkyl, i.e., an alkyl group as defined above is connected to a parent core structure via an oxygen atom. Phrases containing this term, for example, "C1~C6 alkoxy" refers to an alkyl moiety containing 1 to 6 carbon atoms, each occurrence of which can be independently C1 alkoxy, C4 alkoxy, C5 alkoxy, C6 alkoxy. Suitable examples include, but are not limited to, methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt) and tert-butoxy (-OC(CH3)3 or -OtBu).

[0075] "Alkylthio" refers to a group with -S-alkyl, i.e., an alkyl group as defined above is connected to a parent core structure via a sulfur atom. Phrases containing this term, for example, "C1~C6 alkylthio" refers to an alkyl moiety containing 1 to 6 carbon atoms, each occurrence of which can be independently C1 alkylthio, C4 alkylthio, C5 alkylthio, C6 alkylthio. Suitable examples include, but are not limited to, methylthio (-S-CH3 or -SMe), ethylthio (-S-CH2CH3 or -SEt) and tert-butylthio (-SC(CH3)3 or -StBu).

[0076] "Amino" refers to a derivative of ammonia having the structural features of the formula -N(X)2, wherein each "X" is independently H, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, etc. Non-limiting types of amino groups include -NH2, -N(alkyl), -NH(alkyl), -N(cycloalkyl), -NH(cycloalkyl), -N(heterocyclyl), -NH(heterocyclyl), -N(aryl), -NH(aryl), -N(alkyl)(aryl), -N(alkyl)(heterocyclyl), -N(cycloalkyl)(heterocyclyl), -N(aryl)(heteroaryl), -N(alkyl)(heteroaryl), etc.

[0077] "Aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing a hydrogen atom. It can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic rings, at least one is an aromatic ring system. For example, "C5~C 20 "Aryl" refers to an aromatic group containing 5 to 20 carbon atoms, and each occurrence can be independently C5 aromatic group, C6 aromatic group, C 10 Aryl, C 14 Aryl, C 18 Aryl or C 20 Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, perylene, triphenylene, and derivatives thereof.

[0078] "Heteroaryl" means that at least one carbon atom in an aryl group is replaced by a non-carbon atom, such as an N atom, an O atom, or an S atom. For example, "C3~C 20 The term "heteroaryl" refers to a heteroaryl group containing 3 to 20 carbon atoms, and each occurrence may be independently C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C7 heteroaryl or C8 heteroaryl, etc. Suitable examples include, but are not limited to, furan, benzofuran, thiophene, benzothiophene, pyrrole, pyrazole, triazole, imidazole, oxazole, oxadiazole, thiazole, tetrazole, indole, carbazole, pyrroloimidazole, pyrrolopyrrole, thienopyrrole, thienothiophene, furopyrrole, furofuran, thienofuran, benzisoxazole, benzisothiazole, benzimidazole, pyridine, pyrazine, pyridazine, pyrimidine, triazine, quinoline, isoquinoline, o-naphthyridine, quinoxaline, phenanthridine, primary idine, quinazoline and quinazolinone.

[0079] "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.

[0080] In the present application, the single bond to which the substituent is connected runs through the corresponding ring, indicating that the substituent can be connected to any position of the ring, for example R can be connected to any substitutable position of the benzene ring.

[0081] The first aspect of the present application provides a self-assembled hole transport material having the following general structural formula:

[0082] ;

[0083] In the formula, each L is independently C2~C 18 of alkylene;

[0084] Each A is independently an anchoring group;

[0085] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0086] m is an integer from 1 to 4.

[0087] The self-assembled hole transport material is based on the unique structure of tricarbazole phosphorus oxide, which not only retains the appropriate energy level characteristics of carbazole, but also connects the tricarbazole group through the phosphorus oxide group, reduces the degree of conjugation of the molecule, and makes the molecule have a twisted structure. The non-conjugated, twistable connection structure can inhibit the π-π stacking between molecules, so that the self-assembled hole transport material has better dynamic adaptability during the film formation process and improves the uniformity of the film. In addition, the twisted molecular structure allows part of the anchoring group to be anchored on the surface of the metal oxide substrate, and the other part of the anchoring group is located at the leaving end of the substrate, which is conducive to improving the wettability of the perovskite on the hole transport layer and improving the crystal quality of the perovskite layer. And the phosphorus oxygen group can form an adduct by reacting with the Lewis acid-base of the B-site atom such as the lead atom on the perovskite layer, thereby regulating the crystallization of the perovskite and reducing the defects in the perovskite film. Therefore, the self-assembled hole transport material is conducive to improving the uniformity of film formation, improving the wettability of the perovskite layer, and thus improving the efficiency of the device.

[0088] In addition, the self-assembled hole transport material has multiple anchoring groups, and its ability to bind to the substrate is stronger and more stable.

[0089] In conventional technology, self-assembled monolayer hole transport materials were designed based on tri-carbazole and di-carbazole. However, the inventors of the present application found that the self-assembled hole transport materials still have the following problems: (1) The rigid conjugated structure easily forms π-π stacking, which affects the uniformity of film formation; and the wettability of the perovskite layer on the self-assembled hole transport material is poor; (2) The rigid conjugated structure has a complex synthesis route, low yield, and high material cost; (3) The poor film uniformity and high cost also make it unsuitable for large-scale industrial applications.

[0090] The self-assembled hole transport material of some embodiments of the present application is based on tricarbazole phosphorus oxide as the main structure, and three carbazole groups are connected by phosphorus oxide, which reduces the degree of conjugation of the molecule, making the molecule have a twisted structure, part of the anchoring group is anchored on the metal oxide substrate, and part of the anchoring group is located at the leaving end of the substrate, which is conducive to improving the wettability of the perovskite layer. And the non-conjugated and twisted molecular structure is conducive to improving the uniformity of film formation. In addition, the synthesis route of the self-assembled hole transport material of the present application is simple, the yield is high, which is conducive to reducing costs, and is more suitable for large-scale industrial applications.

[0091] In some embodiments, each L is independently a C2-C6 alkylene. 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.

[0092] In some embodiments, each A is independently selected from one of a phosphate group, a sulfonate group, a carboxylate group, and a boronic acid group.

[0093] In some embodiments, each R is independently selected from hydrogen, halogen, C1-C6 alkyl, C1-C6 alkoxy, C1-C6 alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted C5-C 20 Aryl, substituted or unsubstituted C3~C 20 In particular, amino refers to a derivative of ammonia, having a structural feature of the formula -N(X)2, wherein each "X" is independently H, a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, etc. For example, amino can be a substituted or unsubstituted arylamine group, a substituted or unsubstituted heteroarylamine group. More specifically, amino can be a substituted or unsubstituted C3~C 20 Aromatic amino, substituted or unsubstituted C3~C 20 Heteroarylamine,

[0094] Specifically, the substituent in the above substitution is selected from one of hydrogen, halogen, C1~C6 alkyl and C1~C6 alkoxy.

[0095] In some embodiments, each R is independently selected from one of hydrogen, C1-C6 alkyl and C1-C6 alkoxy. Alternatively, each R is independently selected from one of hydrogen, methyl and methoxy.

[0096] m represents the number of R groups and can be 1, 2, 3 or 4.

[0097] In some embodiments, the self-assembled hole transport material is selected from one or more of the following structures:

[0098] , , , , and .

[0099] The second aspect of the present application provides a method for preparing a self-assembled hole transport material, comprising the following steps:

[0100] Providing compound a;

[0101] reacting compound a with XLX to generate compound b;

[0102] reacting the compound b with the ester of the anchoring group to generate a self-assembled hole transport material;

[0103] Wherein, the structural formula of the compound a is , the structural formula of the compound b is , the structural formula of the self-assembled hole transport material is ;

[0104] Wherein, each L is independently C2~C 18 of alkylene;

[0105] Each A is independently an anchoring group;

[0106] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0107] m is an integer from 1 to 4;

[0108] X is halogen.

[0109] In some embodiments, in the step of reacting compound a with XLX, the reaction is carried out at 65° C. to 100° C. for 24 h to 48 h.

[0110] In some of these embodiments, XLX is Br-L-Br.

[0111] In some embodiments, the molar ratio of compound a to XLX is 1:(3-5).

[0112] In some embodiments, the step of reacting compound a with XLX is carried out under alkaline conditions, and the reagent used in the alkaline conditions includes one or more of potassium hydroxide and sodium hydroxide.

[0113] In some of the embodiments, a phase transfer catalyst, such as tetrabutylammonium bromide, is added during the step of reacting compound a with XLX.

[0114] Specifically, compound a undergoes an N-alkyl substitution reaction with XLX to obtain a terminal halogenated product.

[0115] In a specific example, the step of reacting compound a with XLX includes: mixing compound a and XLX at a molar ratio of 1:(3-5) under alkaline conditions and a phase transfer catalyst, and reacting at 65°C-100°C for 24h-48h. After the reaction is completed, extracting with dichloromethane, removing the solvent in the organic phase, and separating by column chromatography to obtain compound b.

[0116] In some embodiments, the anchoring group is a phosphate group, and the step of reacting compound b with the ester of the anchoring group includes: reacting compound b with trialkyl phosphite at 150°C~170°C for 12h~24h, stirring the reaction product with halosilane in 1,4-dioxane for 24h~48h, adding methanol and water, and continuing the reaction for 6h~24h to hydrolyze it to prepare a self-assembled hole transport material.

[0117] Specifically, the trialkyl phosphite includes, but is not limited to, triethyl phosphite.

[0118] Specifically, the halogenated silane includes one or more of trimethylbromosilane, trimethylchlorosilane and triethylbromosilane.

[0119] In some other embodiments, the anchoring group is a carboxylic acid group, and the compound b is reacted with the ester of the anchoring group. The hydrolysis step includes: reacting the compound b with a halogenated carboxylic acid ester, and then hydrolyzing to generate a self-assembled hole transport material.

[0120] It can be understood that in other embodiments, the anchoring group can also be other groups, and the reaction steps can be adjusted according to the different anchoring groups, which will not be described in detail here.

[0121] In some embodiments, the compound a is prepared by the following steps:

[0122] Compound c and compound d are subjected to Suzuki reaction to generate compound e;

[0123] The compound e is subjected to a cyclization reaction under the action of triethyl phosphite to generate the compound a;

[0124] Wherein, the structural formulas of the compound c, the compound d and the compound e are respectively , and , Y is halogen.

[0125] In some embodiments, in the step of subjecting compound c and compound d to Suzuki reaction (also known as Suzuki coupling reaction), the reaction is carried out at 80°C to 150°C for 4h to 24h. For example, the temperature of the Suzuki reaction may be, but is not limited to, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, or a range consisting of any two of these values. The time of the Suzuki reaction may be, but is not limited to, 4h, 6h, 9h, 12h, 15h, 18h, 21h, 24h, or a range consisting of any two of these values.

[0126] Specifically, during the Suzuki reaction, an alkaline reagent, a phase transfer catalyst and a palladium catalyst are also added.

[0127] In one embodiment, the steps of Suzuki reaction of compound c and compound d are as follows: compound c, compound d, an alkaline reagent, a phase transfer catalyst, a palladium catalyst and a solvent are mixed, and reacted at 80° C. to 150° C. for 4 h to 24 h under a protective atmosphere.

[0128] In some embodiments, in the step of subjecting the compound e to a cyclization reaction under the action of triethyl phosphite, the reaction is carried out at 120°C to 180°C for 12h to 48h. For example, the temperature of the cyclization reaction may be, but is not limited to, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or a range consisting of any two of these values. The time of the cyclization reaction may be, but is not limited to, 12h, 15h, 18h, 21h, 24h, 30h, 36h, 42h, 48h, or a range consisting of any two of these values.

[0129] In some of these examples, see Figure 1 The method for preparing the self-assembled hole transport material comprises the following steps:

[0130] Step S110: Compound c and compound d are subjected to Suzuki reaction to generate compound e.

[0131] Step S120: subjecting compound e to a cyclization reaction under the action of triethyl phosphite to generate compound a.

[0132] Step S130: reacting compound a with XLX to generate compound b.

[0133] Step S140: reacting compound b with the ester of the anchoring group to prepare a self-assembled hole transport material.

[0134] The specific steps of the process are as described above and will not be repeated here.

[0135] Figure 1 This is a schematic diagram of a process for preparing a self-assembled hole transport material according to an embodiment of the present invention. It should be understood that although Figure 1 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 1At 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.

[0136] The preparation method of the self-assembled hole transport material has cheap and readily available raw materials, a simple synthesis route, and a high yield, and is suitable for large-scale industrial production and application.

[0137] The third aspect of the present application provides an application of a self-assembled hole transport material in the preparation of an optoelectronic device.

[0138] The above-mentioned optoelectronic device may be, but is not limited to, an organic light emitting diode, a solar cell, etc.

[0139] A fourth aspect of the present application provides a photoelectric device, comprising a substrate, a hole transport layer and a perovskite layer, wherein the substrate comprises a metal oxide, and the hole transport layer is disposed between the substrate and the perovskite layer;

[0140] The material of the hole transport layer includes a self-assembled hole transport material having the following general structural formula:

[0141] ;

[0142] In the formula, each L is independently C2~C 18 The alkyl group;

[0143] Each A is independently an anchoring group;

[0144] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0145] m is an integer from 1 to 4.

[0146] In some embodiments, the hole transport layer is a monolayer structure including the self-assembled hole transport material. The hole transport layer is anchored on the substrate by the anchoring group of the self-assembled hole transport material. At this time, the thickness of the hole transport layer is 1nm to 50nm. For example, the thickness of the hole transport layer can be, but is not limited to, 1nm, 2nm, 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm or a range consisting of any two of these values.

[0147] In some other embodiments, the hole transport layer includes a first sublayer and a second sublayer stacked, the material of the first sublayer is a metal oxide, the material of the second sublayer includes the self-assembled hole transport material, and the first sublayer is arranged between the substrate and the second sublayer. The second sublayer is anchored on the first sublayer by the anchoring group of the self-assembled hole transport material. Specifically, the material of the first sublayer includes but is not limited to nickel oxide. At this time, the thickness of the first sublayer is 10nm~200nm, and the thickness of the second sublayer is 1nm~50nm. For example, the thickness of the first sublayer may be, but is not limited to, 10nm, 20nm, 30nm, 50nm, 60nm, 80nm, 100nm, 120nm, 150nm, 200nm or a range consisting of any two of these values. The thickness of the second sublayer may be, but is not limited to, 1nm, 2nm, 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm or a range consisting of any two of these values.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] Specifically, the material of the electron transport layer includes one or more of fullerene and fullerene derivatives.

[0152] Specifically, the material of the counter electrode is selected from one or more of silver, copper, conductive oxide and carbon electrode.

[0153] 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.

[0154] In some embodiments, the photovoltaic device is a single junction cell, see Figure 2 The optoelectronic device 200 includes a 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 , which are stacked.

[0155] In some other embodiments, the optoelectronic device is a tandem cell. Specifically, the tandem cell includes any one of a perovskite / crystalline silicon tandem cell, a full perovskite tandem cell, a perovskite / organic tandem cell, and a perovskite / CIGS tandem cell. Inverted (pin) perovskite solar cells not only have the advantages of low-temperature processability and excellent stability, but are also compatible with different bottom cells to prepare different tandem solar cells.

[0156] A fifth aspect of the present application provides a method for preparing a photoelectric device, comprising the following steps:

[0157] forming a hole transport layer on a substrate;

[0158] forming a perovskite layer on the hole transport layer to prepare a photoelectric device;

[0159] Wherein, the substrate comprises a metal oxide, and the material of the hole transport layer comprises a self-assembled hole transport material having the following general structural formula:

[0160] ;

[0161] In the formula, each L is independently C2~C 18 The alkyl group;

[0162] Each A is independently an anchoring group;

[0163] Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl;

[0164] m is an integer from 1 to 4.

[0165] In some embodiments, the preparation steps of the hole transport layer include:

[0166] dissolving the self-assembled hole transport material in tetrahydrofuran to obtain a hole transport solution;

[0167] The hole transport solution is applied on the surface of the substrate, and annealed at 100° C. to 150° C. for 5 min to 20 min to anchor the self-assembled hole transport material on the substrate to prepare a hole transport layer.

[0168] In some of the embodiments, before the annealing treatment, a step of rinsing with isopropanol is further included to remove the self-assembled hole transport material that is not anchored to the substrate, which is beneficial to improving the stability of the device.

[0169] In some embodiments, a solution method is used to prepare a perovskite layer. Specifically, a perovskite precursor solution is prepared, and the perovskite precursor solution is spin-coated on the surface of the hole transport layer, annealed, and a perovskite layer is prepared. 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 10 seconds, then spin coating at a speed of 5000 rpm for 30 seconds, and the annealing process is annealing at 100°C for 40 minutes.

[0170] 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.

[0171] Specifically, the electron transport layer is prepared by a solution method. In a specific example, the preparation step of the electron transport layer includes: preparing an electron transport material solution, 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. It can be understood that in some other embodiments, other methods can also be used to form the electron transport layer, such as evaporation.

[0172] Specifically, the hole blocking layer is prepared by a solution method. Specifically, the preparation step of the hole blocking layer includes: dissolving the hole blocking material in isopropanol to a concentration of 0.5 mg / mL, dropping the obtained hole blocking material solution on the electron transport layer, and spin coating at a speed of 5000 rpm for 35 seconds to prepare the hole blocking layer. It can be understood that in other embodiments, other methods can also be used to form the hole blocking layer, such as evaporation method.

[0173] Specifically, the counter electrode is prepared by an evaporation method.

[0174] It can be understood that the above only provides a relatively specific method for preparing an optoelectronic device, but is not limited thereto.

[0175] 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.

[0176] 1. Synthesis Example

[0177] Synthesis Example 1

[0178] This synthesis example provides a self-assembled hole transport material with the structural formula , the synthetic route is as follows:

[0179] , the preparation steps are as follows:

[0180] Step (1) Synthesis of intermediate M11

[0181] Under nitrogen atmosphere, tri(p-bromophenyl)phosphine oxide (1.03 g, 2.0 mmol), 2-nitrobenzeneboronic acid (1.20 g, 7.2 mmol), potassium carbonate (1.24 g, 9.0 mmol) and tetrabutylammonium bromide (64 mg, 0.2 mmol) were dissolved in a mixed solvent of 1,4-dioxane (30 mL) and water (10 mL). After replacing nitrogen by vacuum, tetrakistriphenylphosphine palladium (110 mg, 0.1 mmol) was added and the temperature was raised to 100 °C and refluxed for 12 hours. After the reaction was completed, water was added to quench, and dichloromethane was used for extraction. The organic phase was dried over anhydrous sodium sulfate and concentrated, and further purified by column chromatography. The eluent ratio was petroleum ether: dichloromethane = 10:1 to 3:1 (volume ratio), and finally a white solid M11 (1.05 g, yield 82%) was obtained.

[0182] Step (2) Synthesis of intermediate M12

[0183] Under nitrogen atmosphere, M11 (962 mg, 1.5 mmol) was dissolved in triethyl phosphite (20 mL), heated to 160°C and stirred for 24 hours. When the raw material was exhausted, the excess triethyl phosphite was removed by rotary evaporation, and the crude product was purified by column chromatography with an eluent ratio of petroleum ether: dichloromethane = 10:1 to 0:1 (volume ratio), and finally a white solid product M12 (573 mg, yield 70%) was obtained.

[0184] Step (3) Synthesis of intermediate M13

[0185] The intermediate M12 (545 mg, 1.0 mmol) and tetrabutylammonium bromide (32 mg, 0.1 mmol) were dissolved in 1,4-dibromobutane (15 mL), and then a 50% mass percentage potassium hydroxide aqueous solution (7 mL) was added, and the reaction was stirred at 65°C for 24 hours. After the reaction was completed, water was added to the reaction system to quench the reaction, and the reaction was extracted with dichloromethane. The obtained organic phase was dried over anhydrous sodium sulfate and concentrated, and purified by column chromatography. The eluent ratio was petroleum ether: dichloromethane = 1:0 to 3:1, and finally a colorless viscous product M13 (846 mg, yield 89%) was obtained.

[0186] Step (4) Synthesis of intermediate M14

[0187] Intermediate M13 (800 mg, 0.84 mmol) was dissolved in triethyl phosphite (10 mL) and stirred at 160 °C for 12 hours. After the reaction, the excess triethyl phosphite was removed by rotary evaporation to obtain intermediate M14, which was directly used in the next step without further purification.

[0188] Step (5) Synthesis of Compound P1

[0189] Under nitrogen atmosphere, the intermediate M14 was dissolved in anhydrous 1,4-dioxane (15 mL), trimethylsilyl bromide (1.2 mL) was added, and the reaction was stirred at room temperature for 24 hours. After the reaction was completed, the organic solvent was removed by rotary evaporation, and then methanol (10 mL) was added to dissolve it again, and deionized water was added dropwise until a white solid precipitated in the reaction system, and stirring and hydrolysis were continued for 3 hours, and then a white solid product was obtained by suction filtration. It was redissolved in a small amount of tetrahydrofuran, added dropwise to n-hexane for precipitation, and filtered again to obtain the final product P1, a white solid (703 mg, yield 85%), which is the self-assembled hole transport material of this embodiment. The NMR characterization data of compound P1 are as follows:

[0190] 1H NMR (500 MHz, DMSO-d6) δ 8.14 – 8.04 (m, 6H), 7.95 (s, 6H), 7.78 (d, J = 2.1 Hz, 3H), 7.60 (dd, J = 7.1, 2.2 Hz, 3H), 7.48 – 7.40 (m, 3H), 7.40 – 7.29 (m, 6H), 4.21 (t, J = 5.1 Hz, 6H), 1.96 (dt, J = 11.7, 9.4 Hz, 6H), 1.83 (ddd, J = 11.8, 6.7, 5.2 Hz, 6H), 1.75 – 1.62 (m, 6H).

[0191] 13 C NMR (125 MHz, DMSO-d6) δ 142.92, 139.92, 130.23, 126.29, 125.76,125.70, 122.63, 121.55, 120.37, 119.97, 112.98, 109.54, 43.28, 28.57, 26.02,20.71.

[0192] Synthesis Example 2

[0193] This synthesis example provides a self-assembled hole transport material. The synthesis process thereof is referred to the preparation synthesis example 1, except that in the synthesis of the intermediate M11 in step (1), the 2-nitrobenzene boronic acid in step (1) is replaced with 5-methoxy-2-nitrobenzene boronic acid, the structural formula of which is The remaining preparation steps are the same as those in Synthesis Example 1. The structural formula of the self-assembled hole transport material (denoted as Compound P2) prepared in Synthesis Example 2 is:

[0194] .

[0195] The NMR characterization data of compound P2 are as follows:

[0196] 1 H NMR (500 MHz, DMSO-d6) δ 8.05 (d, J = 6.9 Hz, 3H), 7.95 (s, 6H), 7.75 (d, J = 2.3 Hz, 3H), 7.61 (d, J = 1.9 Hz, 3H), 7.56 (dd, J = 7.1, 2.2Hz, 3H), 7.28 (d, J = 8.2 Hz, 3H), 6.88 (dd, J = 8.2, 1.9 Hz, 3H), 4.21 (t, J= 5.2 Hz, 6H), 3.83 (s, 9H), 2.04 – 1.89 (m, 6H), 1.83 (tt, J = 6.4, 5.4 Hz, 6H), 1.74 – 1.64 (m, 6H).

[0197] 13 C NMR (125 MHz, DMSO-d6) δ 155.02, 142.70, 135.81, 130.22, 126.36,125.55, 122.98, 122.80, 116.68, 112.95, 110.07, 104.90, 55.68, 43.39, 28.57, 26.02, 20.71.

[0198] Synthesis Example 3

[0199] This synthesis example provides a self-assembled hole transport material. The synthesis process thereof is referred to the preparation synthesis example 1, except that in the synthesis of the intermediate M11 in step (1), the 2-nitrobenzene boronic acid in step (1) is replaced with 5-methyl-2-nitrobenzene boronic acid, the structural formula of which is The remaining preparation steps are the same as those in Synthesis Example 1. The structural formula of the self-assembled hole transport material (denoted as Compound P3) prepared in Synthesis Example 3 is:

[0200] .

[0201] The NMR characterization data of compound P3 are as follows:

[0202] 1 H NMR (500 MHz, DMSO-d6) δ 8.03 (d, J = 6.9 Hz, 3H), 7.95 (s, 6H), 7.76 (d, J = 2.2 Hz, 3H), 7.64 (d, J = 1.5 Hz, 3H), 7.58 (dd, J = 6.9, 2.2Hz, 3H), 7.40 (s, 3H), 7.09 (ddd, J = 7.8, 1.9, 1.0 Hz, 3H), 4.21 (t, J = 5.1Hz, 6H), 2.48 (s, 9H), 1.96 (dt, J = 11.7, 9.4 Hz, 6H), 1.83 (ddd, J = 11.8,6.7, 5.2 Hz, 6H), 1.73 – 1.64 (m, 6H).

[0203] 13 C NMR (125 MHz, DMSO-d6) δ 142.49, 138.19, 130.79, 130.23, 126.27,125.56, 125.54, 122.42, 121.31, 112.96, 108.90, 43.39, 28.57, 26.02, 21.36,20.71.

[0204] Synthesis Example 4

[0205] This synthesis example provides a self-assembled hole transport material. The synthesis process thereof is referred to the preparation of Synthesis Example 1, except that in the synthesis of intermediate M11 in step (1), 2-nitrobenzeneboronic acid in step (1) is replaced by 4-methoxy-2-nitrobenzeneboronic acid, the structural formula of which is The remaining preparation steps are the same as those in Synthesis Example 1. The structural formula of the self-assembled hole transport material (denoted as Compound P4) prepared in Synthesis Example 4 is:

[0206] .

[0207] The NMR characterization data of compound P4 are as follows:

[0208] 1 H NMR (500 MHz, DMSO-d6) δ 8.06 (d, J = 6.9 Hz, 3H), 7.95 (s, 6H), 7.84 (d, J = 7.9 Hz, 3H), 7.75 (d, J = 2.3 Hz, 3H), 7.61 (dd, J = 6.9, 2.2Hz, 3H), 7.12 (d, J = 2.2 Hz, 3H), 6.86 (dd, J = 8.0, 2.2 Hz, 3H), 4.23 (t, J= 5.2 Hz, 6H), 3.82 (s, 9H), 2.03 – 1.92 (m, 6H), 1.83 (tt, J = 6.4, 5.4 Hz, 6H), 1.75 – 1.62 (m, 6H).

[0209] 13 C NMR (125 MHz, DMSO-d6) δ 160.10, 142.76, 141.47, 130.22, 126.34,125.29, 122.85, 122.84, 116.10, 112.95, 109.33, 94.37, 55.91, 43.23, 28.57, 26.02, 20.71.

[0210] Synthesis Example 5

[0211] This synthesis example provides a self-assembled hole transport material. The synthesis process thereof is similar to that of Synthesis Example 2. The only difference is that in the synthesis of intermediate M13 in step (3), tetrabutylammonium bromide in step (3) is replaced with dibutylammonium bromide. The remaining preparation steps are the same as those of Synthesis Example 2. The structural formula of the self-assembled hole transport material prepared in Synthesis Example 5 (denoted as Compound P5) is:

[0212] .

[0213] The NMR characterization data of compound P5 are as follows:

[0214] 1 H NMR (500 MHz, DMSO-d6) δ 8.44 (s, 6H), 8.05 (d, J = 6.9 Hz, 3H), 7.75 (d, J = 2.2 Hz, 3H), 7.61 (d, J = 1.9 Hz, 3H), 7.56 (dd, J = 7.1, 2.2Hz, 3H), 7.26 (d, J = 8.2 Hz, 3H), 6.88 (dd, J = 8.2, 1.9 Hz, 3H), 4.37 (t, J= 7.9 Hz, 6H), 3.83 (s, 9H), 2.24 (dt, J = 11.8, 7.9 Hz, 6H).

[0215] 13 C NMR (125 MHz, DMSO-d6) δ 155.02, 141.53, 135.21, 130.22, 126.36,125.55, 123.04, 122.81, 116.68, 112.87, 110.09, 104.90, 55.68, 34.43, 26.66.

[0216] Synthesis Example 6

[0217] This synthesis example provides a self-assembled hole transport material. The synthesis process thereof is similar to that of Synthesis Example 3. The only difference is that in the synthesis of intermediate M13 in step (3), tetrabutylammonium bromide in step (3) is replaced with dibutylammonium bromide. The remaining preparation steps are the same as those of Synthesis Example 3. The structural formula of the self-assembled hole transport material prepared in Synthesis Example 6 (denoted as Compound P6) is:

[0218] .

[0219] The NMR characterization data of compound P6 are as follows:

[0220] 1 H NMR (500 MHz, DMSO-d6) δ 8.44 (s, 6H), 8.03 (d, J = 6.9 Hz, 3H), 7.76 (d, J = 2.2 Hz, 3H), 7.64 (d, J = 1.7 Hz, 3H), 7.58 (dd, J = 6.9, 2.2Hz, 3H), 7.40 (s, 3H), 7.09 (ddd, J = 8.0, 2.0, 1.1 Hz, 3H), 4.37 (t, J = 7.9Hz, 6H), 2.48 (s, 9H), 2.24 (dt, J = 11.8, 7.9 Hz, 6H).

[0221] 13 C NMR (125 MHz, DMSO-d6) δ 141.39, 137.20, 130.79, 130.22, 126.27,125.56, 125.54, 122.59, 122.43, 121.31, 112.83, 109.02, 34.43, 26.65, 21.36.

[0222] 2. Device Examples

[0223] Device Example 1

[0224] This device embodiment provides an inverted perovskite solar cell, and the preparation steps are as follows:

[0225] (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.

[0226] (2) 2 mg of the self-assembled hole transport material P1 synthesized in Synthesis Example 1 was dissolved in 1 mL of tetrahydrofuran, added dropwise to the surface of the ITO conductive glass, and spin-coated at 3000 rpm for 30 s. The surface was then dynamically rinsed once with 300 μL of isopropanol, and then annealed at 100°C for 10 min to form a self-assembled hole transport layer with a thickness of 3 nm.

[0227] (3) Dissolve 922 mg of lead iodide, 348 mg of iodomethane, 45.46 mg of cesium iodide, 13.5 mg of chloromethylamine and 55.62 mg of lead chloride in 1 mL of a mixed solvent of N,N-dimethylformamide and N-methylpyrrolidone (volume ratio of 1000:192), 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 ITO conductive glass that forms the self-assembled hole transport layer. First, spin coat it at 1000 rpm for 10 s, then spin coat it at 5000 rpm for 30 s, and then put the ITO conductive glass on a hot stage and heat anneal it at 100 °C for 40 min to form a perovskite layer with a thickness of 650 nm.

[0228] (4) Dissolve 20 mg of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) in 1 mL of chlorobenzene and stir at room temperature to obtain a [6,6]-phenyl-C61-butyric acid methyl ester solution. Take 30 μL of the [6,6]-phenyl-C61-butyric acid methyl ester solution and drop it on the ITO conductive glass with a perovskite layer. Spin coat at 3000 rpm for 60 s to form an electron transport layer with a thickness of 20 nm.

[0229] (5) Dissolve 0.5 mg of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in 1 mL of isopropanol and stir at room temperature to obtain a hole blocking layer solution. Take 40 μL of the hole blocking layer solution and drop it onto the electron transport layer. Spin coat at 5000 rpm for 35 s to form a hole blocking layer with a thickness of 6 nm.

[0230] (6) The ITO conductive glass formed with the hole blocking layer, PCBM electron transport layer, perovskite layer, and self-assembled hole transport layer was transferred to the vacuum coating instrument and the vacuum degree was drawn to 3×10 -4 Silver was evaporated at 400 Å Pa to form a silver electrode with a thickness of 100 nm, thereby obtaining the perovskite solar cell of the device embodiment.

[0231] Device Example 2

[0232] This device embodiment provides a perovskite solar cell, and the preparation steps are similar to those of device embodiment 1, except that in step (2) of this device embodiment, the self-assembled hole transport material used is compound P2 prepared in synthesis embodiment 2. The other steps are the same as those in embodiment 1 and will not be repeated.

[0233] Device Example 3

[0234] This device embodiment provides a perovskite solar cell, and the preparation steps are similar to those of device embodiment 1, except that in step (2) of this device embodiment, the self-assembled hole transport material used is compound P3 prepared in synthesis embodiment 3. The other steps are the same as those in embodiment 1 and will not be repeated.

[0235] Device Example 4

[0236] This device embodiment provides a perovskite solar cell, and the preparation steps are similar to those of device embodiment 1, except that in step (2) of this device embodiment, the self-assembled hole transport material used is compound P4 prepared in synthesis embodiment 4. The other steps are the same as those in embodiment 1 and will not be repeated.

[0237] Device Example 5

[0238] This device embodiment provides a perovskite solar cell, and the preparation steps are similar to those of device embodiment 1, except that in step (2) of this device embodiment, the self-assembled hole transport material used is compound P5 prepared in synthesis embodiment 5. The other steps are the same as those in embodiment 1 and will not be repeated.

[0239] Device Example 6

[0240] This device embodiment provides a perovskite solar cell, and the preparation steps are similar to those of device embodiment 1, except that in step (2) of this device embodiment, the self-assembled hole transport material used is compound P6 prepared in synthesis embodiment 6. The other steps are the same as those in embodiment 1 and will not be repeated.

[0241] Device Comparison Example 1

[0242] Device Comparative Example 1 provides a perovskite solar cell, and the preparation steps are similar to those of Example 1, except that in step (2) of the device comparative example 1, the self-assembled hole transport material used is [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), and the other steps are the same as those of Example 1 and will not be repeated herein.

[0243] The performance of the perovskite solar cells prepared by the above device embodiments and device comparative examples was tested, and the data shown in the following Table 1 were obtained.

[0244] Table 1

[0245]

[0246] It can be understood that in the above test process, each device was tested three times. For example, in device embodiment 1, T1, T2 and T3 represent the results of the three tests respectively.

[0247] It can be seen from Table 1 that the photoelectric conversion performance of the device example is significantly better than that of the device comparison example. Therefore, by optimizing the structure of the self-assembled hole transport material, it is beneficial to improve the photoelectric conversion performance of the device.

[0248] 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.

[0249] 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 has the following general structural formula: ； In the formula, each L is independently C2~C 18 of alkylene; Each A is independently an anchoring group; Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl; m is an integer from 1 to 4.

2. The self-assembled hole transport material according to claim 1, characterized in that: One or more of the following conditions are met: (1) Each L is independently a C2-C6 alkylene group; (2) Each A is independently selected from a phosphate group, a sulfonate group, a carboxylate group and a borate group; (3) Each R is independently selected from one of hydrogen, C1~C6 alkyl and C1~C6 alkoxy; optionally, each R is independently selected from one of hydrogen, methyl and methoxy.

3. The self-assembled hole transport material according to claim 1 or 2, characterized in that: The self-assembled hole transport material is selected from one or more of the following structures: , , , , and .

4. A method for preparing a self-assembled hole transport material, characterized in that: The steps include: Providing compound a; The compound a is reacted with XLX to generate compound b; reacting the compound b with the ester of the anchoring group to generate a self-assembled hole transport material; Wherein, the structural formula of the compound a is , the structural formula of the compound b is , the structural formula of the self-assembled hole transport material is ; Wherein, each L is independently C2~C 18 of alkylene; Each A is independently an anchoring group; Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl; m is an integer from 1 to 4; Each X is independently halogen.

5. The method for preparing the self-assembled hole transport material according to claim 4, characterized in that: The compound a is prepared by the following steps: Compound c and compound d are subjected to Suzuki reaction to generate compound e; The compound e is subjected to a cyclization reaction under the action of triethyl phosphite to generate the compound a; Wherein, the structural formulas of the compound c, the compound d and the compound e are respectively , and , each Y is independently halogen.

6. Use of the self-assembled hole transport material according to any one of claims 1 to 3 or the self-assembled hole transport material prepared by the preparation method according to any one of claims 4 to 5 in preparing optoelectronic devices.

7. A photoelectric device, characterized in that: The method comprises a substrate, a hole transport layer and a perovskite layer, wherein the substrate comprises a metal oxide, and the hole transport layer is arranged between the substrate and the perovskite layer; The material of the hole transport layer includes a self-assembled hole transport material having the following general structural formula: ； In the formula, each L is independently C2~C 18 of alkylene; Each A is independently an anchoring group; Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl; m is an integer from 1 to 4.

8. The optoelectronic device according to claim 7, characterized in that: The hole transport layer is a single-layer structure including the self-assembled hole transport material, and the self-assembled hole transport material is anchored on the substrate; Alternatively, the hole transport layer includes a first sublayer and a second sublayer which are stacked, the material of the first sublayer includes a metal oxide, the material of the second sublayer includes the self-assembled hole transport material, the first sublayer is arranged between the substrate and the second sublayer, and the self-assembled hole transport material is anchored on the first sublayer.

9. The optoelectronic device according to claim 7 or 8, characterized in that: The photoelectric device also includes 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.

10. 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; Wherein, the substrate comprises a metal oxide, and the material of the hole transport layer comprises a self-assembled hole transport material having the following general structural formula: ； In the formula, each L is independently C2~C 18 of alkylene; Each A is independently an anchoring group; Each R is independently selected from one of hydrogen, halogen, alkyl, alkoxy, alkylthio, hydroxyl, thiol, cyano, amino, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl; m is an integer from 1 to 4.

11. The method for preparing a photoelectric device according to claim 10, characterized in that: The preparation steps of the hole transport layer include: dissolving the self-assembled hole transport material in tetrahydrofuran to obtain a hole transport solution; The hole transport solution is applied on the surface of the substrate, and annealed at 100° C. to 150° C. for 5 min to 20 min to anchor the self-assembled hole transport material on the substrate to prepare a hole transport layer.

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