WO2023109035A1

WO2023109035A1 - Compound and use thereof in solar cell

Info

Publication number: WO2023109035A1
Application number: PCT/CN2022/097587
Authority: WO
Inventors: 董鑫; 何博; 杨泽君; 张华�
Original assignee: 西安隆基乐叶光伏科技有限公司
Priority date: 2021-12-17
Filing date: 2022-06-08
Publication date: 2023-06-22
Also published as: CN116283897A

Abstract

Disclosed is an application of a compound in a solar cell. The structural formula of the compound is (C)n-L-(M)m, wherein n≥1 and m≥1; a C structure is selected from at least one of conjugated structural units of aromatic hydrocarbons and derivatives thereof or heterocyclic compounds and derivatives thereof; L is a chain segment having a carboxylate radical, a sulfonate radical and a phosphate radical at an end group, and the chain segment is at least one of an alkyl chain having 0-20 carbon atoms, an alkoxy chain, an ether oxygen chain, a phenyl group, a silyl group, or a nitrogen-containing fragment; and M is selected from at least one of hydrogen, an alkali metal, an alkaline earth metal or a transition metal. The present application further provides a solar cell and a preparation method therefor. The compound of the present application, when used in a solar cell, can not only adjust the energy level matching at the lower interface of a perovskite absorption layer and passivate interface defects, thereby improving interface contact of a device and reducing carrier recombination at the lower interface, but also solve the problems that the efficiency of the solar cell is difficult to further improve and the stability decreases.

Description

A kind of compound and the application of this compound in solar cell

Cross References to Related Applications

This disclosure claims priority to a Chinese patent application with application number 202111555379.9 entitled "A Compound and Application of the Compound in Solar Cells" filed with the China Patent Office on December 17, 2021, the entire contents of which are incorporated by reference in this disclosure.

technical field

The present application relates to the technical field of solar cells, in particular to a compound and the application of the compound in solar cells, a solar cell, a stacked solar cell and a preparation method thereof.

Background technique

Organic-inorganic hybrid perovskite solar cells have attracted extensive attention as a new type of high-efficiency and low-cost solar cells. In just a few years, the photoelectric conversion efficiency of small-area perovskite cells has risen rapidly from 3.8% in 2009 to more than 25%. In addition, perovskite solar cells can be efficiently and mass-produced by solution processing methods such as slit coating, spray coating, doctor blade coating, and roll-to-roll. Compared with traditional silicon-based solar energy, it has the advantages of low manufacturing cost, simple processing technology and flexible device preparation, and has good commercial prospects.

Common perovskite solar cell devices are p-i-n type (transparent electrode/hole transport layer/perovskite active layer/electron transport layer/metal electrode) and n-i-p type (transparent electrode/electron transport layer/perovskite active layer/ hole transport layer/metal electrode) in two configurations. Regardless of the device structure, the preparation process of the perovskite layer will inevitably produce some point defects, anti-site ion defects, and atomic clusters in the bulk and interface defects, resulting in a decrease in device efficiency. Compared with bulk defects, the carrier recombination caused by interface defects is an important factor that causes the decrease of open circuit voltage and device performance of battery devices. At present, there are two commonly used defect passivation methods: 1. Passivation reagents are added as additives to the precursor solution, which has a weak effect on interface passivation; 2. Prepare an interface passivation layer on the upper layer of perovskite , this method can only passivate the upper interface. However, more and more studies have found that the buried interface defects in the lower layer of perovskite have a greater impact on device performance, and the effective passivation of the lower interface passivation defects is a very important direction to further improve device efficiency.

Contents of the invention

In view of the above problems, the present application proposes a compound, which is used in solar cells as a hole transport functional layer, which can adjust the energy level matching at the lower interface of the perovskite absorber layer, passivate interface defects, and improve the device interface. contact, reduce the carrier recombination at the lower interface, and at the same time, it can also solve the problem that the efficiency of solar cells is difficult to further improve and the stability decreases.

The application provides a compound, the structural formula of the compound is (C)n-L-(M)m, n≥1, m≥1,

The C structure is selected from at least one of the conjugated structural units of aromatic hydrocarbons and their derivatives or heterocyclic compounds and their derivatives;

L is a chain segment with carboxylate, sulfonate, or phosphate at the end group, and the chain segment is an alkyl chain with 0 to 20 carbon atoms, an alkoxy chain, an ether oxygen chain, a phenyl group, a silyl group, or at least one of the nitrogen-containing fragments;

M is at least one selected from hydrogen, alkali metals, alkaline earth metals or transition metals.

Further, the C structure is selected from thiophene and its derivatives, thiophene and its derivatives, pyrrole and its derivatives, pyridine and its derivatives, benzene and its derivatives, fluorene and its derivatives, carbazole and its Derivatives, at least one of triarylamine and its derivatives.

Further, the C structure has at least one of the following structures:

Further, the structural formula of the compound is selected from the following:

The present application also provides a preparation method of the compound, and the compound is synthesized through route one, route two, route three or route four, wherein,

Route 1:

Add _AlCl3 in batches to the solution containing succinic anhydride, after the reaction, slowly add the aromatic hydrocarbon containing the C structure or its derivatives or heterocyclic compound or its derivatives dropwise, and obtain compound 1a after the reaction is completed;

Compound 1a is reduced by hydrazine hydrate under alkaline conditions, and the pH is adjusted after the reaction is completed, thereby obtaining Compound 1b;

Wherein the structural formula of compound 1a is:

The structural formula of compound 1b is:

Route two:

Under alkaline conditions, add EtOOC(CH ₂ ) _n Br to the solution of the aromatic hydrocarbon or its derivatives or heterocyclic compounds or its derivatives containing the C structure to carry out the alkylation reaction at the N atom position, after the reaction is complete Compound 2a is obtained;

The solution of compound 2a is subjected to ester hydrolysis reaction under alkaline conditions, and the pH is adjusted after the reaction to obtain compound 2b;

Wherein the structural formula of compound 2a is:

The structural formula of compound 2b is:

Route three:

Under anhydrous and oxygen-free alkaline conditions, add Br(CH ₂ ) _n Br to the solution containing the aromatic hydrocarbon or its derivatives or heterocyclic compounds or its derivatives containing the C structure to carry out sp3C atomic position of the cyclopentadiene unit The alkylation reaction of the compound 3a is obtained after the reaction;

Compound 3a reacts with a cyanide reagent to obtain compound 3b after the reaction;

Compound 3b is subjected to cyano hydrolysis under alkaline conditions, and after the reaction, acid is used to adjust the pH to obtain compound 3c;

Wherein, the structural formula of compound 3a is:

The structural formula of compound 3b is:

The structural formula of compound 3c is:

Route 4:

Add dropwise the solution containing alkali into the solution containing A-COOH, adjust its pH after the reaction, and continue the reaction to obtain the organic metal salt product A-COOM;

where A is

one of

M is metal.

Further, in the route 1, succinic anhydride and anhydrous dichloromethane are mixed and stirred evenly to obtain a mixed solution 1, and cooled, and AlCl is added in batches to the mixed solution ₁ for reaction, and then slowly added dropwise The solution of aromatic hydrocarbon or its derivatives or heterocyclic compound or its derivatives containing C structure, after the dropwise addition, continue to react until the reaction is complete to obtain the mixed solution 2, pour the mixed solution 2 into ice water, and then Adjust the pH, then extract the aqueous phase, combine the organic phases, then dry, filter, spin off the solvent, and separate to obtain compound 1a;

Mix and dissolve compound 1a and diethylene glycol to obtain a mixed solution 3, and cool it down, add hydrazine hydrate and potassium hydroxide to the mixed solution 3, heat and react to obtain a mixed solution 4, adjust the mixed solution 4 pH, and then filtered and recrystallized to obtain compound 1b.

Further, once the mixed solution is cooled to 0°C, anhydrous AlCl ₃ is added therein to react for 1-2h;

Pour the mixed solution 2 into ice water, and then adjust its pH so that the pH is 2, then extract the aqueous phase with dichloromethane, and combine the organic phases;

Cool the mixed solution 3 to 0°C, then add hydrazine hydrate and potassium hydroxide to the mixed solution 3, heat the reaction to reflux, continue the reaction for 2-6 hours, and then lower the reaction solution to room temperature to obtain a mixed solution Fourth, adjust the pH of the mixed solution to 2 or 7, and then undergo suction filtration and recrystallization to obtain 1b.

Further, in the route two, Bu ₄ NHSO ₄ and benzene are sequentially added to the solution containing aromatic hydrocarbons or derivatives thereof or heterocyclic compounds or derivatives thereof, stirred evenly, and NaOH aqueous solution is added dropwise, stirred Finally, EtOOC(CH ₂ ) _n Br was added dropwise therein. After the dropwise addition was completed, the temperature was raised to continue the reaction to obtain the mixed solution 5, and then the organic phase was washed several times with water, and the solvent was removed by spin to obtain the product compound 2a;

Potassium hydroxide aqueous solution and ethanol were sequentially added to compound 2a, heated to react to obtain mixed solution 6, the pH of the mixed solution 6 was adjusted, and then filtered and recrystallized to obtain 2b.

Further, in the route two, Bu ₄ NHSO ₄ and benzene are sequentially added to the solution containing aromatic hydrocarbons or derivatives thereof or heterocyclic compounds or derivatives thereof, stirred evenly, and NaOH aqueous solution is added dropwise, stirred Finally, continue to add the bromoester compound EtOOC(CH ₂ )nBr dropwise therein. After the dropwise addition is completed, raise the temperature to 50-80°C and continue the reaction to obtain the mixed solution 5. The mixed solution 5 is cooled to room temperature, and the organic phase Wash several times with water, spin off the solvent, and separate by column chromatography to obtain the product compound 2a;

Add potassium hydroxide aqueous solution and ethanol in sequence to compound 2a, heat to reflux, and then cool to 0°C to obtain mixed solution 6, adjust the pH of the mixed solution 6 to 2 or 7, then undergo suction filtration and recrystallization to obtain compound 2b .

Further, in the route three, tetrahydrofuran is added to the solution of aromatic hydrocarbons containing C structure or derivatives thereof or heterocyclic compounds or derivatives thereof, and then ventilated, stirred and cooled, and BuLi is slowly added dropwise therein, After the dropwise addition, react to obtain the mixed solution 7, add the mixed solution 7 dropwise to the tetrahydrofuran solution containing Br(CH ₂ ) _n Br, after the dropwise addition, obtain the mixed solution 8, pour the mixed solution 8 into water, Extract, then combine the organic phases, then dry, filter, spin off the solvent, and separate to obtain compound 3a;

Add 18-crown ether-6, potassium cyanide, and acetonitrile to compound 3a, stir evenly, and heat to react to obtain mixed liquid 9, pour mixed liquid 9 into water, wash, then adjust the pH of the aqueous phase, and then combine the organic phase, and then dried, filtered, spin off the solvent, and separated to obtain compound 3b;

Add potassium hydroxide, ethanol, and water to compound 3b, stir evenly, and heat to react to obtain a mixed liquid 10, pour the mixed liquid 10 into water, extract several times, adjust the pH of the aqueous phase, and then use suction filtration, heavy Crystallization gave the product compound 3c.

Further, in the route three, under anhydrous and oxygen-free conditions, tetrahydrofuran is added to the solution of aromatic hydrocarbons or derivatives thereof or heterocyclic compounds or derivatives thereof containing C structure, and then the gas is ventilated, stirred and cooled to -20°C, slowly add BuLi dropwise to it, after the dropwise addition, rise to room temperature to react to obtain the mixed solution 7, add the mixed solution 7 dropwise to the tetrahydrofuran solution containing Br(CH ₂ )nBr, and dropwise add the reaction system Keep the temperature at 0°C, after the dropwise addition, rise to room temperature to react to obtain the mixed solution 8, pour the mixed solution 8 into water, extract with ether, then combine the organic phases, dry, filter, and spin off the solvent to obtain the crude product , the resulting crude product was separated by column chromatography to obtain compound 3a;

Add 18-crown ether-6, potassium cyanide, and acetonitrile to compound 3a, stir evenly, and heat to reflux reaction to obtain mixed solution 9, cool the mixed solution 9 to room temperature, and pour mixed solution 9 into water , washing with ether, adjusting the pH of the aqueous phase to 7, then combining the organic phases, drying, filtering, and spinning off the solvent to obtain a crude product, which was separated by column chromatography to obtain compound 3b;

Add potassium hydroxide, ethanol and water (2.5:1, 15mL) to compound 3b, stir evenly, and heat to reflux reaction to obtain mixed solution 10; The mixed solution 10 is cooled to room temperature, and it is poured into water, using After extraction with ether several times, the pH of the aqueous phase was adjusted to 2 or 7, and the product compound 3c was obtained by suction filtration and recrystallization.

Further, A-COOH was dissolved in DMSO, and the ethanol solution of the metal hydroxide was slowly added dropwise therein to obtain the mixed solution eleven, and then the pH of the mixed solution eleven was adjusted, and the reaction was continued to obtain the mixed solution twelve, and the reaction After the end, the mixed solution was filtered under reduced pressure and dried to obtain the corresponding organometallic salt product A-COOM.

Further, in the route four, A-COOH is dissolved in DMSO, and the ethanol solution of the metal hydroxide is slowly added dropwise therein to obtain the mixed solution eleven, and then the pH of the mixed solution eleven is adjusted to 7.0, and continued After reacting for 0.5-6 hours, the mixed solution 12 was obtained. After the reaction, the mixed solution 12 was filtered under reduced pressure and dried to obtain the corresponding organometallic salt product A-COOM.

The application also provides an application of the compound in solar cells.

The present application also provides a solar cell, including a substrate, a hole transport functional layer, a perovskite absorption layer, an electron transport layer, and a top electrode that are sequentially stacked from bottom to top;

The hole transport functional layer contains (C)n-L-(M)m;

The (C)n-L-(M)m is the compound (C)n-L-(M)m described in any one of claims 1-4.

Further, the hole transport functional layer is a hole transport layer and a modification layer laminated together, and the hole transport layer is laminated with the substrate, and the modification layer is laminated with the perovskite absorbing layer together.

Further, the modification layer is a (C)n-L-(M)m layer with a thickness of 0.1-30nm;

The thickness of the hole transport layer is 1-150nm.

Further, the hole transport functional layer is a mixture of the hole transport layer material and the modification layer material, and the hole transport functional layer is formed on the surface of the substrate.

Further, the modification layer material contains compound (C)n-L-(M)m;

In the hole transport functional layer, the mass ratio of compound (C)n-L-(M)m in the modification layer material to the hole transport layer material is 0.01%-99.9%;

The thickness of the hole-transporting functional layer is 0.1-50 nm.

Further, the hole transport functional layer is a (C)n-L-(M)m layer with a thickness of 0.1-30 nm.

Further, when the solar cell is a single cell, the substrate includes a transparent cell substrate and a TCO layer laminated together, and the TCO layer and the hole transport functional layer are laminated together.

Further, when the solar cell is a stacked cell, the substrate includes a silicon-based cell and a TCO layer stacked together, and the TCO layer is stacked with the hole transport functional layer.

The present application also provides a method for preparing a solar cell, comprising the steps of:

provide the basis;

preparing a hole transport functional layer on one side surface of the substrate;

preparing a perovskite absorbing layer on the surface of the hole transport functional layer away from the substrate;

preparing an electron transport layer on a surface of the perovskite absorption layer away from the hole transport functional layer;

preparing a top electrode on the surface of the side of the electron transport layer away from the perovskite absorbing layer;

The hole transport functional layer contains (C)n-L-(M)m;

The (C)n-L-(M)m is the compound (C)n-L-(M)m described in any one of claims 1-9.

Further, the prepared solar cell is the aforementioned solar cell.

The compound provided by the application is used in solar cells as a hole-transporting functional layer. The group C of the compound mainly plays the role of charge transport and regulation of molecular energy levels; the group L is an acid-containing end group connection segment and mainly serves as a connection conductive segment. and metal ions, and the role of passivating the adjacent upper and lower layer defects; the group M is a metal ion that can react or dope with the perovskite absorber layer, passivate the interface defects, and adjust the interface energy level matching. Part of the structure is synergistic, so that it can not only adjust the energy level matching at the lower interface of the perovskite absorbing layer of the solar cell, passivate the interface defect, improve the device interface contact, reduce the carrier recombination at the lower interface, but also solve the problem of perovskite The device efficiency is difficult to further improve and the problem of stability decline.

The above description is only an overview of the technical solution of the present disclosure. In order to better understand the technical means of the present disclosure, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present disclosure more obvious and understandable , the specific embodiments of the present disclosure are enumerated below.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following will briefly introduce the drawings that need to be used in the descriptions of the embodiments or related technologies. Obviously, the drawings in the following description are the For some disclosed embodiments, those skilled in the art can also obtain other drawings based on these drawings without any creative work.

The accompanying drawings are used for better understanding of the present application, and do not constitute an improper limitation of the present application. in:

FIG. 1 is a schematic structural diagram of a solar cell provided by the present application.

Fig. 2 is a schematic structural diagram of a tandem solar cell provided by the present application.

FIG. 3 is a characteristic curve of fluorescence properties of the perovskite absorbing layer of the solar cell in Example 2 and Comparative Example 1 provided by the present application.

Explanation of reference signs

11-substrate, 12-hole transport functional layer, 14-perovskite absorption layer, 15-electron transport layer, 16-top electrode, 21-upper battery, 22-lower battery, 23-composite layer.

specific embodiment

The following describes the exemplary embodiments of the present application, including various details of the embodiments of the present application to facilitate understanding, and they should be considered as exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the application. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness. In this application, the upper and lower positions are determined according to the incident direction of light, and the incident light is up.

Since the modification of the lower interface of the perovskite absorbing layer needs to be carried out before the preparation of the perovskite absorbing layer, it is not only necessary to consider whether the preparation process will destroy the underlying structure (such as hole transport layer, substrate, etc.), but also to consider when preparing the perovskite absorbing layer. Whether it will destroy the modification layer; therefore, it is difficult to choose a suitable modification material for the lower interface.

Therefore, in order to solve the above problems and improve the efficiency of perovskite solar cells and the stability of devices, this application adopts an organic metal salt compound as the passivation material for the lower interface of the perovskite absorbing layer. The compound is mainly composed of three parts: a conductive segment, an acid radical-containing end group connection segment and a metal ion. The conductive segment has a certain ability to transport charges, which is beneficial to the transport and extraction of carriers at the interface. The connecting segment containing the acid radical end group connects the conductive segment and the metal ion, and at the same time, the acid radical end group can interact with the uncoordinated Pb at the lower interface of the perovskite absorbing layer to passivate the defects at the lower interface of the perovskite absorbing layer. O can also interact with the TCO layer in the underlying substrate, passivating surface defects on the substrate. The metal ions can be alkali metals, alkaline earth metals or transition metals, and the metal ions can react or dope with the perovskite absorber layer to passivate interface defects and adjust interface energy level matching. For example, K+ ions can form a two-dimensional perovskite K ₂ PbI ₄ structure with the perovskite absorber layer, eliminate residual PbI ₂ , and effectively weaken the hysteresis of battery devices; Ni ²⁺ doping can effectively suppress defects in the internal structure of perovskite , improve the defect formation energy, and then increase the short-range order of the perovskite absorber layer, thereby improving the device performance. This type of organometallic salt compound can be prepared on the hole transport layer as an interface passivation layer, that is, a modification layer, or it can be configured as a mixed solution with a hole transport material to directly prepare the hole transport functional layer 12, or It directly replaces the hole transport layer and plays the role of hole transport and interface passivation.

The organometallic salt compound is hereinafter referred to as the compound, and the specific description is as follows:

In the present application, the structural formula of the compound is (C)n-L-(M)m, n≥1, m≥1,

The C structure is at least one selected from conjugated structural units such as aromatic hydrocarbons and their derivatives or heterocyclic compounds and their derivatives;

L is a terminal group, having a chain segment of carboxylate, sulfonate, and phosphate, and the chain segment is an alkyl chain, an alkoxy chain, an ether oxygen chain, a silyl group, a phenyl group, a chain containing At least one of nitrogen groups, etc., C can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20;

It is preferably a chain segment with carboxylate, sulfonate, or phosphate, and the chain segment is an alkyl chain with a C number of 0, 1, 2, 3, or 4, an alkoxy chain, an ether oxygen chain, a silyl group, a benzene At least one of group, nitrogen-containing group, etc.;

M is at least one selected from hydrogen, alkali metals, alkaline earth metals, and transition metals. Preferred is hydrogen or potassium.

Preferably, the C structure is at least one selected from bithiophene, nathiophene, naphthalene, benzothiophene, pyridine, fluorene, and carbazole.

In this application, the C structure has at least one of the following structures:

In a specific embodiment, the C structure is selected from at least one of conjugated structural units such as aromatic rings and their derivatives or heterocyclic rings and their derivatives; L is a terminal group with carboxylate, sulfonate, phosphate A chain segment, the chain segment is at least one of an alkyl chain, an alkoxy chain, an ether oxygen chain, a silyl group, a phenyl group, a nitrogen-containing group, etc. with a C number of 0 to 20, and M is selected from hydrogen, At least one of alkali metals, alkaline earth metals, and transition metals.

In a specific embodiment, the C structure is selected from thiophene and its derivatives, thiophene and its derivatives, pyrrole and its derivatives, pyridine and its derivatives, benzene and its derivatives, fluorene and its derivatives, carbazole At least one of triarylamine and its derivatives, triarylamine and its derivatives; L is a terminal group, with a segment of carboxylate, sulfonate, and phosphate, and the segment is an alkyl chain with a C number of 0-20 , at least one of alkoxy chains, ether oxygen chains, silyl groups, phenyl groups, nitrogen-containing groups, etc., and M is at least one selected from hydrogen, alkali metals, alkaline earth metals, and transition metals.

In a specific embodiment, the C structure is selected from at least one of conjugated structural units such as aromatic rings and their derivatives or heterocycles and their derivatives; L is a segment with carboxylate, sulfonate, and phosphate, The chain segment is at least one of alkyl chains, alkoxy chains, ether oxygen chains, silyl groups, phenyl groups, nitrogen-containing groups, etc. with C numbers of 0, 1, 2, 3, and 4, and M is selected from At least one of hydrogen, alkali metals, alkaline earth metals, and transition metals.

In a specific embodiment, the C structure is selected from at least one of conjugated structural units such as aromatic rings and their derivatives or heterocyclic rings and their derivatives; L is a terminal group with carboxylate, sulfonate, phosphate A chain segment, the chain segment is at least one of an alkyl chain, an alkoxy chain, an ether oxygen chain, a silyl group, a phenyl group, a nitrogen-containing group, etc. with a C number of 0 to 20, and M is selected from hydrogen, One or both of potassium.

In a specific embodiment, the C structure is selected from thiophene and its derivatives, thiophene and its derivatives, pyrrole and its derivatives, pyridine and its derivatives, benzene and its derivatives, fluorene and its derivatives, carbazole and its derivatives, at least one of triarylamine and its derivatives; L is a chain segment with carboxylate, sulfonate, and phosphate, and the chain segment is C number 0, 1, 2, 3, 4 At least one of alkyl chains, alkoxy chains, ether oxygen chains, silyl groups, phenyl groups, nitrogen-containing groups, etc., and M is at least one selected from hydrogen, alkali metals, alkaline earth metals, and transition metals.

In a specific embodiment, the C structure is selected from thiophene and its derivatives, thiophene and its derivatives, pyrrole and its derivatives, pyridine and its derivatives, benzene and its derivatives, fluorene and its derivatives, carbazole At least one of triarylamine and its derivatives, triarylamine and its derivatives; L is a terminal group, with a segment of carboxylate, sulfonate, and phosphate, and the segment is an alkyl chain with a C number of 0-20 , an alkoxy chain, an ether oxygen chain, a silyl group, a phenyl group, a nitrogen-containing group, etc., and M is selected from one or both of hydrogen and potassium.

In a specific embodiment, the C structure is selected from at least one of conjugated structural units such as aromatic rings and their derivatives or heterocycles and their derivatives; L is a segment with carboxylate, sulfonate, and phosphate, The chain segment is at least one of alkyl chains, alkoxy chains, ether oxygen chains, silyl groups, phenyl groups, nitrogen-containing groups, etc. with C numbers of 0, 1, 2, 3, and 4, and M is selected from One or both of hydrogen or potassium.

In a specific embodiment, the C structure is selected from thiophene and its derivatives, thiophene and its derivatives, pyrrole and its derivatives, pyridine and its derivatives, benzene and its derivatives, fluorene and its derivatives, carbazole and its derivatives, at least one of triarylamine and its derivatives; L is a chain segment with carboxylate, sulfonate, and phosphate, and the chain segment is C number 0, 1, 2, 3, 4 At least one of an alkyl chain, an alkoxy chain, an ether oxygen chain, a silyl group, a phenyl group, a nitrogen-containing group, etc., and M is selected from one or both of hydrogen and potassium.

In this application, the compound can be the following:

The application provides a preparation method of a compound, specifically as follows:

Route 1:

Wherein the structural formula of 1a is:

The structural formula of 1b is:

The specific steps are: mix and stir succinic anhydride and anhydrous dichloromethane to obtain a mixed solution 1, cool to 0°C, add anhydrous _AlCl3 to the mixed solution in batches for 1-2 hours, and then slowly add After the aromatic hydrocarbon containing the C structure or its derivatives or heterocyclic compound or its derivatives is added dropwise, it is raised to room temperature and the reaction is continued until the reaction is complete to obtain the mixed solution 2. Pour the mixed solution 2 into ice water, then adjust the pH so that the pH is 2, then extract the aqueous phase with dichloromethane, combine the organic phases, and then dry, filter, spin off the solvent, recrystallize or use a column Chromatography affords 1a.

Mix and dissolve 1a and diethylene glycol to obtain a mixed solution 3, and cool it to 0°C, add hydrazine hydrate and potassium hydroxide to the mixed solution 3, heat the reaction, and cool the reaction solution to room temperature to obtain a mixed solution Fourth, adjust the pH of the mixed solution to 2 or 7. Then after suction filtration and recrystallization, 1b was obtained;

More specifically, the synthesis steps of 1a: Add succinic anhydride (10.0mmol, 1.0equiv) and 20mL of anhydrous DCM to a two-necked flask in sequence, stir the mixed solution, cool to 0°C, and add anhydrous AlCl ₃ (12.0mmol, 1.2equiv), continue to react for 1-2h. Slowly add the aromatic compound to be reacted dropwise. After the dropwise addition, rise to room temperature and continue the reaction until the reaction is complete. The reaction mixture was poured into 30m ice water, and the pH was adjusted to 2 with 2N HCl. The aqueous phase was extracted three times with DCM, the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by spin. The crude product was recrystallized with PE/ethyl acetate or separated by column chromatography (PE/EA=2:1, with 0.3% CH ₃ COOH), the pure product 1a was obtained.

1b: Add 1a (65.2mmol, 1.0equiv) and 250mL of diethylene glycol into the two-necked flask at one time, and stir to dissolve. The mixed solution was cooled to 0° C., and hydrazine hydrate (2.19 equiv, 143 mmol) and KOH (2.19 equiv, 143 mmol) were added to the reaction flask. The reaction mixture was heated to reflux, and the reaction was continued for 4h. The reaction solution was cooled to room temperature, and the pH was adjusted to pH=7 with 2N HCl. Suction filtration, the filter cake was washed several times with cold methanol solution, and the filter cake was collected. The filter cake can also be purified by methanol recrystallization. The pure product 1b was obtained.

Route two:

Wherein the structural formula of 2a is:

The structural formula of 2b is:

The specific steps are: adding Bu ₄ NHSO ₄ and benzene in sequence to the solution containing the aromatic hydrocarbon or its derivative or heterocyclic compound or its derivative containing the C structure, stirring evenly, adding NaOH aqueous solution dropwise, after stirring, adding Continue to add the bromoester compound EtOOC(CH ₂ )nBr dropwise. After the dropwise addition is completed, the temperature is raised to continue the reaction to obtain the mixed solution 5. The mixed solution was cooled to room temperature, the organic phase was washed several times with water, the solvent was removed by spin, and the product 2a was obtained by column chromatography;

Add KOH aqueous solution and ethanol in sequence to 2a, heat to reflux, and then cool to 0° C. to obtain mixed solution 6, and adjust the pH of the mixed solution 6 to 2 or 7. Then, 2b was obtained through suction filtration and recrystallization;

Further specific legal steps are:

Synthetic steps of 2a: Add the solution (1.0 equiv) of the aromatic hydrocarbon or its derivative or heterocyclic compound or its derivative containing the C structure, Bu ₄ NHSO ₄ (0.24 equiv), 130 mL of benzene into a two-necked flask in sequence, Aqueous 50% NaOH (25 mL) was added dropwise with stirring. After stirring for 5 min, the desired bromoester compound EtOOC(CH ₂ )nBr(2.1 equiv) was added dropwise. After the dropwise addition, the temperature was raised to 60° C. to continue the reaction for 4 h. Cool at room temperature, wash the organic phase with water several times, and spin off the solvent. Column chromatography (PE/ethyl acetate 9:1) gave the product 2a.

Synthesis steps of 2b: 2a (3.82mmol), 10% KOH aqueous solution (45mL) and ethanol (20mL) were sequentially added to a two-necked flask, heated to reflux for 20min, cooled to 0°C, and adjusted to pH=7 with 2N HCl. Suction filtration, the filter cake was washed several times with cold methanol solution, and the filter cake was collected. The filter cake can also be purified by methanol recrystallization. The pure product 2b was obtained.

Route three:

Wherein, the structural formula of 3a is:

The structural formula of 3b is:

The structural formula of 3c is:

The specific steps are: under anhydrous and oxygen-free conditions, add tetrahydrofuran to the solution of the aromatic hydrocarbon or its derivatives or heterocyclic compound or its derivatives containing the C structure, then pump and ventilate, stir and cool, and slowly drop Add BuLi, after the dropwise addition, rise to room temperature for reaction to obtain the mixed solution 7, add the mixed solution 7 dropwise to the tetrahydrofuran solution containing Br(CH ₂ ) _n Br, keep the temperature of the reaction system at 0°C during the dropping process, and drop After the addition was completed, it was raised to room temperature for reaction to obtain a mixed solution 8. Pour the mixed liquid 8 into water, extract with ether, then combine the organic phases, dry, filter, and spin off the solvent to obtain a crude product, which is separated by column chromatography to obtain 3a.

Add 18-crown ether-6, potassium cyanide and acetonitrile to 3a, stir evenly, and heat to reflux for reaction to obtain mixed solution 9. The mixed solution 9 was cooled to room temperature, the mixed solution 9 was poured into water, and washed with ether. Adjust the pH of its aqueous phase to 7, then combine the organic phases. After drying, filtering, and spinning off the solvent to obtain a crude product, the obtained crude product was separated by column chromatography to obtain 3b;

Potassium hydroxide, ethanol and water (2.5:1, 15 mL) were added to 3b, stirred evenly, and heated to reflux to obtain a mixed solution 10. The mixture was cooled to room temperature, poured into water, extracted several times with ether, and the pH of the aqueous phase was adjusted to 2 or 7. Then adopt suction filtration and recrystallization to obtain product 3c;

The further specific steps are, the synthesis steps of 3a are: under anhydrous and oxygen-free conditions, sequentially add aromatic hydrocarbons or derivatives thereof or heterocyclic compounds or derivatives thereof containing the C structure to be reacted in the reaction flask (1.0equiv, 5.05 mmol), anhydrous THF (20mL), and gas exchange three times. Stir and cool to -20°C, slowly add BuLi (1.6M in hexane, 1.01 equiv, 5.12mmol) dropwise. After the dropwise addition, warm up to room temperature and react for 1 h, then add the reaction mixture dropwise into a solution of Br(CH ₂ ) _n Br (1.0 equiv, 5.05 mmol) in THF (10 mL), and keep the temperature of the reaction system at 0°C during the dropping process . After the dropwise addition, it was raised to room temperature and reacted for 1 h. The reaction mixture was poured into water, extracted three times with ether, and the organic phases were combined. Dry over anhydrous Na ₂ SO ₄ , filter, and spin off the solvent to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 9:1) to obtain pure product 3a.

The synthesis steps of 3b are as follows: add 3a (1.01equiv, 1.22mmol), 18-Crown-6 (0.3equiv, 0.37mmol), KCN (7.55equiv, 9.22mmol), acetonitrile (15mL) into a three-necked flask in sequence, stir and heat Reflux reaction 10h. After the reaction was complete, cool to room temperature, pour the reaction mixture into water, and wash with ether several times. The pH of the aqueous phase was adjusted to pH=7 with 2N HCl. Combine the organic phases. Dry over anhydrous Na ₂ SO ₄ , filter, and spin off the solvent to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 8:2) to obtain pure product 3b.

The synthesis steps of 3c are: add 3b (1.01equiv, 0.62mmol), KOH (34.5equiv, 21.40mmol), ethanol:water (2.5:1, 15mL) into a three-necked flask in sequence, stir, and heat to reflux for 3h. After the reaction was complete, cool to room temperature, pour the reaction mixture into water, and extract with ether several times. The pH of the aqueous phase was adjusted to pH=7 with 2N HCl. Suction filtration, the filter cake was washed several times with cold methanol solution, and the filter cake was collected. The filter cake can also be purified by methanol recrystallization. The pure product 3c was obtained.

Route 4:

where A is

one of

M is metal.

The specific steps are as follows: dissolve A-COOH in DMSO, and slowly add the ethanol solution of metal hydroxide dropwise therein to obtain the mixed solution 11, then adjust the pH of the mixed solution 11 to 7.0, and continue the reaction to obtain the mixed solution 11 2. After the reaction is finished, the mixed solution is filtered under reduced pressure and dried to obtain the corresponding organometallic salt product A-COOM;

A further specific step is to dissolve 1 eq of A-COOH in a solvent such as DMSO, and slowly add an ethanol solution (0.5M in 10% ethanol) of a metal hydroxide (such as KOH, NaOH, etc.) dropwise at r.t.～100°C, Adjust the pH to ~7.0, react at the same temperature for 30min-6h under stirring. After the reaction, filter under reduced pressure, wash the filter cake with cold methanol, collect the filter cake, and freeze-dry for 36 hours or vacuum-dry to obtain the corresponding organometallic salt product.

Specifically, the synthetic route of 2TAK is as follows:

Using 2TA as raw material, 2TAK was synthesized according to the synthetic route. The specific steps are:

Dissolve 1eq of 2TA in DMSO and other solvents, slowly add potassium hydroxide ethanol solution (0.5M in 10% ethanol) dropwise at 100°C, adjust the pH to 7.0, and react for 6h under stirring at the same temperature. After the reaction, filter under reduced pressure, wash the filter cake with cold methanol, collect the filter cake, and freeze-dry for 36 hours or vacuum-dry to obtain 2TAK. ¹ H NMR (DMSO-d6, 400MHz) δ (ppm): 7.12 (dd, J = 6.8Hz, J = 4.8Hz, 1H), 7.33 (d, J = 5.2Hz 1H), 7.47 (d, J = 4.8 Hz, 1H), 7.61 (d, J=6.8Hz, 1H).

Specifically, the synthetic route of O-2TAK is as follows:

The specific steps are: Synthetic steps of 4a: add 2-methoxy-5 bromothiophene (1equiv), 5-carboxythiophene-2-boronic acid (1equiv) and Na ₂ CO ₃ (2equiv) to the Schleck tube successively, pump Take a breath. Pd(PPh ₃ ) ₄ (5 mol%) was added into the glove box. The solvent acetonitrile (20 mL) was then added and heated to 80° C. for 12 h. After the reaction was complete, it was lowered to room temperature, poured into water, extracted the aqueous phase with dichloromethane (DCM), combined the organic phases, dried over anhydrous Na ₂ SO ₄ , filtered, and the solvent was spin-off to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 9:1) to obtain product 4a (yield 80%). ¹ H NMR (CDC1 ₃ , 400 MHz) δ (ppm): 3.70 (s, 3H), 7.02-7.09 (m, 3H), 7.17 (d, J=5.2Hz, 1H), 10.5 (s, 1H).

O-2TAK: The synthesis method is the same as that described in Route 4. Yield 90%. ¹ H NMR (CDC1 ₃ , 400 MHz) δ (ppm): 3.70 (s, 3H), 7.02-7.09 (m, 3H), 7.17 (d, J = 5.2 Hz, 1H).

Specifically, the synthetic routes of O-2TAK4, O-3TAK, and 3TAK are as follows:

Synthesis of O-2TAK4, O-3TAK, 3TAK:

5a1: 5a1 was synthesized by route 1, using thiophene as the starting material, with a yield of 72%. ¹ H NMR (DMSO-d6) δ (ppm): 2.56 (t, J = 6.7Hz, 2H), 3.18 (t, J = 6.7Hz, 2H), 7.23 (t, J = 4.8Hz, 1H,), 7.68(dd, J=4.8/0.9Hz, 1H), 7.72(dd, J=4.8/0.9Hz, 1H), 12.2(bs, 1H).

5a2 was synthesized by route 1, using bithiophene as the starting material, and the yield was 69%. ¹ H NMR (DMSO-d6) δ (ppm): 2.56 (t, J = 6.7Hz, 2H), 3.18 (t, J = 6.7Hz, 2H), 6.67 (d, J = 3.6Hz, 1H), 6.97 (d, J=3.6Hz, 1H), 6.98(dd, J=4.7Hz, J=3.6Hz, 1H), 7.09(d, J=3.6Hz, 1H), 7.17(d, J=4.7Hz, 1H ), 12.2(bs,1H).

5b1: 5b1 was synthesized by route 1, starting from 5a1, with a yield of 72%. ¹ H NMR (DMSO-d6) δ (ppm): 1.95 (q, J = 7.4Hz, 2H), 2.34 (t, J = 7.4Hz, 2H), 2.82 (t, J = 7.4Hz, 2H), 6.72 (dd, J=3.5/1.1Hz, 1H), 6.84 (dd, J=5.1/3.5Hz, 1H), 7.05 (dd, J=5.1/1.1Hz, 1H), 10.7 (bs, 1H).

5b2: 5b2 was synthesized by route 1, starting from 5a2, with a yield of 75%. ¹ H NMR (CDC1 ₃ ) δ (ppm): 1.39-1.72 (m, 2H), 2.36 (t, 2H), 2.79 (t, 2H), 6.67 (d, J=3.6Hz, 1H), 6.97 (d ,J=3.6Hz,1H),6.98(dd,J=4.7Hz,J=3.6Hz,1H),7.09(d,J=3.6Hz,1H),7.17(d,J=4.7Hz,1H), 10.7(bs,1H).

5c1: Add 5b1 (1 equ.) and 30 mL of anhydrous DMC into the reaction flask, stir and lower the temperature to 0°C. Add NBS (1.2equ.) in batches, warm up to room temperature after the addition, and react in the dark for 8 hours. The reaction mixture was poured into water, extracted three times with ether, and the organic phases were combined. Dry over anhydrous Na ₂ SO ₄ , filter, and spin off the solvent to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 9:1) to obtain the pure product 5c1 with a yield of 85%. ¹ H NMR (DMSO-d6) δ (ppm): 1.95 (q, J = 7.4Hz, 2H), 2.34 (t, J = 7.4Hz, 2H), 2.82 (t, J = 7.4Hz, 2H), 6.72 (dd, J=7.5Hz, 1H), 6.93 (dd, J=7.5Hz, 1H), 10.7(bs, 1H).

5c2: 5c2 was synthesized by route 1, starting from 5b2, with a yield of 81%. ¹ H NMR (CDC1 ₃ ) δ (ppm): 1.39-1.72 (m, 2H), 2.36 (t, 2H), 2.79 (t, 2H), 6.67 (m, J = 3.6Hz, 1H), 6.97 (d , J=3.6Hz, 1H), 6.98 (dd, J=4.7Hz, J=3.6Hz, 1H), 7.09 (d, J=3.6Hz, 1H), 10.7 (bs, 1H).

5d1: The synthesis method is the same as that of 4a to synthesize 5d1. Starting from 5c1, the yield was 88%. ¹ H NMR (DMSO-d6) δ (ppm): 1.95 (q, J = 7.4Hz, 2H), 2.34 (t, J = 7.4Hz, 2H), 2.82 (t, J = 7.4Hz, 2H), 3.70 (s, 3H), 6.72(d, J=7.5Hz, 1H), 6.93(d, J=7.5Hz, 1H), 6.98(d, J=7.5Hz, J=3.6Hz, 1H), 7.09(d , J=7.5Hz, 1H), 10.7(bs, 1H).

5d2: The synthesis method is the same as that of 4a to synthesize 5d2. Starting from 5c2, the yield was 87%. ¹ H NMR (CDCl ₃ ) δ (ppm): 1.35-1.78 (m, 2H), 2.36 (t, 2H), 2.79 (t, 2H), 3.70 (s, 3H), 6.68 (d, J = 3.6Hz ,1H),6.97(d,J=3.6Hz,1H),6.99(d,J=3.7Hz,1H),7.02(dd,J=3.7Hz,J=5.1Hz,1H),7.05(d,J= 3.7Hz, 1H), 7.15(d, J=3.6Hz, 1H), 7.19(d, J=5.1Hz, 1H), 10.7(bs, 1H).

5d3: The synthesis method is the same as that of 4a to synthesize 5d3. Starting from 5c3, the yield is 90%. ¹ H NMR (CDCl ₃ ) δ (ppm): 1.35-1.78 (m, 4H), 2.36 (t, 4H), 2.79 (t, 4H), 6.68 (d, J=3.6Hz, 1H), 6.97 (d ,J=3.6Hz,7H),6.99(d,J=3.7Hz,2H),7.05(d,J=3.7Hz,2H),7.15(d,J=3.6Hz,2H),10.7(bs,1H ).

O-2TAK4: O-2TAK4 was synthesized by route 4, starting from 5d1, with a yield of 80%. ¹ H NMR (DMSO-d6) δ (ppm): 1.95 (q, J = 7.4Hz, 2H), 2.34 (t, J = 7.4Hz, 2H), 2.82 (t, J = 7.4Hz, 2H), 3.70 (s, 3H), 6.72(d, J=7.5Hz, 1H), 6.93(d, J=7.5Hz, 1H), 6.98(d, J=7.5Hz, J=3.6Hz, 1H), 7.09(d , J=7.5Hz, 1H).

O-3TAK: O-3TAK was synthesized by route 4, starting from 5d2, with a yield of 83%. ¹ H NMR (CDCl ₃ ) δ (ppm): 1.35-1.78 (m, 2H), 2.36 (t, 2H), 2.79 (t, 2H), 3.70 (s, 3H), 6.68 (d, J = 3.6Hz ,1H),6.97(d,J=3.6Hz,1H),6.99(d,J=3.7Hz,1H),7.02(dd,J=3.7Hz,J=5.1Hz,1H),7.05(d,J= 3.7Hz, 1H), 7.15(d, J=3.6Hz, 1H), 7.19(d, J=5.1Hz, 1H).

3TAK: 3TAK was synthesized by route 4, starting from 5d3, with a yield of 75%. ¹ H NMR (CDCl ₃ ) δ (ppm): 1.35-1.78 (m, 4H), 2.36 (t, 4H), 2.79 (t, 4H), 6.68 (d, J=3.6Hz, 1H), 6.97 (d , J=3.6Hz, 7H), 6.99 (d, J=3.7Hz, 2H), 7.05 (d, J=3.7Hz, 2H), 7.15 (d, J=3.6Hz, 2H).

Specifically, the synthetic route of PyAK is as follows:

6b: 6b was synthesized by route 2, starting from 6a, with a yield of 75%. ¹ H NMR(CDCI ₃ )δ(ppm):1.20(t,3H),1.35-1.87(m,2H),2.35(t,2H),4.10(q,2H),4.20(t,2H),7.00 -7.10 (AB system, J=5.2Hz, 4H).

PyAK: PyAK was synthesized by route 2, starting from 6b, with a yield of 81%. ¹ H NMR (CDCI ₃ ) δ (ppm): 1.35 (m, 2H), 2.25 (t, 2H), 4.20 (t, 2H), 7.00-7.10 (AB system, J=5.2Hz, 4H).

Specifically, the synthetic route of C2TAK is:

7b: 7b was synthesized by Route 3, starting from 7a, with a yield of 65%. ¹ H NMR (CDCI ₃ ) δ (ppm): 1.50-1.80 (m, 4H), 3.39 (t, 2H), 3.52 (t, 2H), 7.05-7.15 (AB system, J=5.2Hz, 4H).

7c: 7c was synthesized by route 3, starting from 7b, with a yield of 93%. ¹ H NMR (CDCI ₃ ) δ (ppm): 1.40-2.30 (m, 4H), 3.49 (t, 1H), 3.65 (t, 2H), 7.05-7.15 (AB system, J=5.2Hz, 4H).

C2TAK: C2TAK was synthesized by route 3, starting from 7c, with a yield of 65%. ¹ H NMR (CDCI ₃ ) δ (ppm): 1.50 (m, 2H), 2.30 (t, 2H), 3.51 (t, 1H), 7.05-7.15 (AB system, J=5.2Hz, 4H).

The above compounds are used in solar cells as follows:

As shown in FIG. 1 , the present application provides a solar cell, which includes a substrate 11 , a hole transport functional layer 12 , a perovskite absorption layer 14 , an electron transport layer 15 and a top electrode 16 stacked sequentially from bottom to top.

Further, the substrate 11 includes a transparent battery substrate and a TCO layer laminated together, and the TCO layer and the hole transport functional layer 12 are laminated together.

In this application, the transparent battery substrate may be transparent glass, organic polymers such as PET, and the like.

The TCO layer can be fluorine-doped tin oxide (FTO), indium tin oxide (ITO) or aluminum-doped zinc oxide (AZO); the thickness of the TCO layer is 50-1000nm, for example, it can be 50nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm, 750nm, 800nm, 850nm, 900nm, 950nm or 1000nm.

The electron transport layer 15 can be a titanium oxide layer, a tin oxide layer, a C60 layer or a C60-PCBM layer, [60]PCBM ([6,6]-phenyl-C ₆₁ butyric acid methyl ester, the Chinese name is [ 6,6]-phenyl-C ₆₁ -butyric acid methyl ester) layer, [70]PCBM ([6,6]-Phenyl-C ₇₁ -butyric acid methyl ester, the Chinese name is [6,6]-benzene base-C ₇₁ -isomethyl butyrate) layer, bis[60]PCBM (Bis(1-[3-(methoxycarbonyl)propyl]-1-phenyl)-[6,6]C ₆₂ ) layer, [60] ICBA(1',1",4',4"-Tetrahydro-di[1,4]methanonaphthaleno[1,2:2',3',56,60:2",3"][5,6]fullerene -C60) layer, etc., including but not limited to this, as long as the functions in this application can be realized.

The perovskite absorption layer 14 may be an organic-inorganic hybrid halide perovskite layer, an all-inorganic halide perovskite layer, a lead-free perovskite layer, etc., including but not limited thereto. Its thickness is 200-5000nm, such as 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm, 1200nm, 1300nm, 1400nm, 1500nm, 1600nm, 1700nm, 1800nm, 1900nm, 2000nm , 2100nm, 2200nm, 2300nm, 2400nm, 2500nm, 3000nm, 3500nm, 4000nm, 4500nm or 5000nm.

The top electrode 16 is a metal electrode layer, which can be made of one or more of metal materials such as Ag, Au, Cu, Al, Ni, C material, and polymer conductive material, and its thickness can be 0.1 μm- 50 μm, for example, may be 0.1 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm.

In the present application, the hole-transporting functional layer 12 consists of three structures, specifically as follows:

The first structure: the hole transport functional layer 12 is a hole transport layer and a modification layer stacked together, and the hole transport layer and the substrate 11 are stacked together, the modification layer and the perovskite The ore absorbing layers 14 are stacked together.

The hole transport layer can be a molybdenum oxide layer, [bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) layer, copper iodide layer or Spiro-OMeTAD (2 ,2',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (4-methoxyphenyl)amino]-9,9'-spirobifluorene) layer, PEDOT layer, PEDOT:PSS layer, P3HT layer, P3OHT layer, P3ODDT layer, NiOx layer or CuSCN layer.

The thickness of the hole transport layer may be 1-150nm, for example, 1nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm or 150nm.

The modification layer is a (C)n-L-(M)m layer with a thickness of 0.1-30nm, such as 0.1nm, 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm , 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, or 30 nm.

In the first structure, the modification layer is not only used to passivate the lower interface defects of the perovskite absorbing layer 14 to reduce interfacial recombination, but also to adjust the surface work function of the hole transport layer to make it It matches the energy level of the perovskite absorbing layer 14; further, the lower interface of the perovskite absorbing layer 14 is the surface laminated with the modification layer.

The second structure: the hole transport functional layer 12 is a mixture of the hole transport layer material and the modification layer material, and the hole transport functional layer 12 is formed on the surface of the substrate 11 .

Specifically, the hole transport layer material is dissolved in a solvent to obtain solution 1, the modification layer material is dissolved in a solvent to obtain solution 2, and then solution 1 and solution 2 are mixed to obtain a mixed solution, and then the mixed solution is spin-coated or spray-coated or soaking to form the hole transport functional layer 12 on the surface of the substrate 11 . The solvent is selected from at least one of amides, alcohols, esters, ketones, ethers or sulfones/sulfoxides.

The modification layer material contains compound (C)n-L-(M)m;

In the hole transport functional layer 12, the mass ratio of the compound (C)n-L-(M)m in the modification layer material to the hole transport layer material is 0.01% to 99.9%, for example, it can be 0.01%. , 1%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99.9%;

The thickness of the hole transport functional layer 12 is 0.1-50nm, for example, 0.1nm, 1nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm.

Existing hole transport materials can better modify the oxide semiconductor conductive layer, but due to poor carrier transport performance or energy level matching, it is difficult to extract charges, resulting in obvious battery hysteresis. After the hole transport material is doped with (C)n-L-(M)m, the formed hole transport functional layer has groups interacting with the underlying semiconductor conductive layer and can interact with the upper perovskite absorbing layer. The formation of a two-dimensional perovskite interface layer is beneficial to reduce the defect state density at the lower interface, weaken the carrier recombination at the lower interface, and facilitate charge extraction.

The third structure: the hole transport functional layer 12 is a (C)n-L-(M)m layer with a thickness of 0.1-30nm, such as 0.1nm, 1nm, 10nm, 15nm, 20nm, 25nm, 30nm.

In the compound (C)n-L-(M)m, C is an organic conjugated segment, which makes it have hole transport ability, and L contains groups interacting with the lower semiconductor conductive layer, which can passivate the defects of the lower conductive layer , and the M group can form a two-dimensional structure with the upper perovskite absorber layer. (C)n-L-(M)m passivates the upper and lower interface defects at the same time, and can adjust the energy level at the interface to make it more conducive to carrier extraction, and can simultaneously function as a hole transport layer and a modification layer.

When the hole-transporting functional layer 12 of the first structure is applied in a solar cell, the specific preparation method is as follows:

The application provides a method for preparing a solar cell, comprising the steps of:

Step 1: providing a substrate 11;

Step 2: preparing a hole transport layer on one side surface of the substrate 11;

Step 3: preparing a modification layer on the surface of the hole transport layer facing away from the substrate 11;

Step 4: preparing a perovskite absorbing layer 14 on the surface of the modification layer facing away from the hole transport layer;

Step 5: preparing an electron transport layer 15 on the surface of the perovskite absorbing layer 14 away from the modification layer;

Step 6: Prepare a top electrode 16 on the surface of the electron transport layer 15 facing away from the perovskite absorbing layer 14 .

In step one, a TCO layer is prepared on the transparent battery substrate, so as to obtain the substrate 11 .

Specifically, the TCO layer may be a transparent conductive film, which may be fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), and the like.

In step 2, on the surface of the TCO layer away from the transparent battery substrate, it is prepared by any one of the processing methods of spin coating, blade coating, slit coating, spray coating, printing, vacuum deposition, and film drawing The hole transport layer has a thickness in the range of 1-150nm.

In step 3, first configure the modification layer solution, dissolve the compound (C)n-L-(M)m in solvents such as amides, alcohols, esters, ketones, ethers or sulfone/sulfoxides, and prepare into a modification layer solution with a concentration of 0.1mM-1M; and then apply the modification layer solution by any one of the processing methods of spin coating, scrape coating, soaking, slit coating, spray coating, printing, vacuum deposition, and film drawing A modification layer is formed on the surface of the hole transport layer facing away from the substrate 11 .

The thickness of the modification layer is 0.1-30 nm, preferably 1-5 nm.

In step 4, the perovskite precursor solution is coated on the surface of the modification layer away from the hole transport layer by any one of the processing methods of spin coating, blade coating, slit coating, spray coating, printing, and vacuum deposition. One side surface, thereby forming the perovskite absorbing layer 14.

Specifically, the perovskite precursor solution contains metal halides (the metal halides contain at least one of Pb, Cs, Rb, and K), formamidine halide salts, methylamine halide salts, etc. Organic amine salts, other organic and inorganic additives. The perovskite precursor solution needs to be heated, gas-phase method, anti-solvent method, vacuum desolventization, etc. to form the perovskite absorbing layer 14 on the modified layer.

Specifically, the general chemical formula of the perovskite absorbing layer 14 is ABX ₃ , wherein A is a monovalent metal cation or an organic cation, which can be selected from: CH ₃ NH ₃ , C ₄ H ₉ NH ₃ , NH ₂ =CHNH _2. At least one of Cs; B is a divalent metal cation, which can be selected from at least one of Pb and Sn; X is a monovalent anion, which can be selected from halogen elements such as Cl, Br or I, SCN-, etc. At least one or more of the pseudohalogens, such as multiple X ions, the total ratio of which satisfies the general chemical formula of the composition of the perovskite absorbing layer 14 . In order to better absorb sunlight, the thickness of the perovskite absorbing layer 14 may range from 200 nm to 5000 nm.

In Step 5, electron transport is prepared on the surface of the perovskite absorbing layer 14 away from the modified layer by vacuum deposition, spin coating, doctor blade coating, slit coating, spray coating, printing, ALD and other processing methods. Layer 15, the electron transport layer 15 has a thickness in the range of 1-150 nm.

In step six, a TCO layer is prepared on the surface of the electron transport layer 15 facing away from the perovskite absorbing layer 14, and then a TCO layer is used on the surface of the TCO layer facing away from the electron transport layer 15. The metal electrode layer is prepared by evaporation, printing, electroplating, silk screen and other processing methods. The TCO layer and the metal electrode layer form the top electrode 16. The TCO layer is a transparent conductive film, which can be fluorine-doped tin oxide (FTO) , indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), etc. The material used for the metal electrode can be selected from one or more of Ag, Au, Cu, Al, Ni and other metal materials, C material, polymer conductive material, and the thickness of the top electrode 16 is 0.1 μm-50 μm.

Step 1: providing a substrate 11;

Specifically, a TCO layer is prepared on a transparent battery substrate to obtain a substrate 11 . The TCO layer may be fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), and the like.

Specifically, on the surface of the TCO layer away from the transparent battery substrate, holes are prepared by any one of spin coating, blade coating, slit coating, spray coating, printing, vacuum deposition, and film drawing. The transport layer has a thickness in the range of 1-150nm.

Specifically, first configure the modification layer solution, and dissolve the compound (C)n-L-(M)m in solvents such as amides, alcohols, esters, ketones, ethers or sulfone/sulfoxides, and make the concentration The modification layer solution is 0.1mM-1M; then, the modification layer solution is coated on the The side surface of the hole transport layer facing away from the substrate 11 forms a modified layer.

The thickness of the modification layer is 0.1-30 nm, preferably 1-5 nm.

Specifically, the electron transport layer 15 is prepared on the surface of the perovskite absorbing layer 14 away from the modified layer by vacuum deposition, spin coating, doctor blade coating, slit coating, spray coating, printing, ALD and other processing methods. , the thickness range of the electron transport layer 15 is 1-150nm.

Step 6: Prepare a top electrode 16 on the side surface of the electron transport layer 15 away from the perovskite absorption layer 14;

Specifically, a TCO layer is prepared on the surface of the electron transport layer 15 facing away from the perovskite absorbing layer 14, and then on the surface of the TCO layer facing away from the electron transport layer 15, evaporation , printing, electroplating, silk screen and other processing methods to prepare the metal electrode layer, the TCO layer and the metal electrode layer form the top electrode 16, the TCO layer is a transparent conductive film, which can be fluorine-doped tin oxide (FTO), oxide Indium tin (ITO), aluminum-doped zinc oxide (AZO), etc. The material used for the metal electrode can be selected from one or more of Ag, Au, Cu, Al, Ni and other metal materials, C material, polymer conductive material, and the thickness of the top electrode 16 is 0.1 μm-50 μm.

In the present application, the solar cell prepared by the above preparation method is the aforementioned solar cell, and the parameters of the solar cell can refer to the description of the aforementioned solar cell.

When the hole-transporting functional layer 12 of the second structure is applied in a solar cell, the specific preparation method is as follows:

Step 1: providing a substrate 11;

Step 2: preparing a hole transport functional layer 12 on one side surface of the substrate 11;

Step 3: preparing a perovskite absorbing layer 14 on the surface of the hole transport functional layer 12 facing away from the substrate 11;

Step 4: preparing an electron transport layer 15 on the surface of the perovskite absorbing layer 14 away from the modification layer;

Step five: preparing a top electrode 16 on the surface of the electron transport layer 15 facing away from the perovskite absorbing layer 14 .

In step 2, firstly, the hole transport layer material is dissolved in a solvent to obtain a solution 1, and the modification layer material is dissolved in a solvent to obtain a solution 2, and then the solution 1 and the solution 2 are mixed to obtain a mixed solution, and then the mixed The hole transport functional layer 12 is formed on the surface of the substrate 11 by spin coating, spray coating or soaking. The solvent is selected from at least one of amides, alcohols, esters, ketones, ethers or sulfones/sulfoxides.

The hole transport layer material is selected from molybdenum oxide, [bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), copper iodide or Spiro-OMeTAD (2,2 ',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene Chinese name is 2,2',7,7'-four[N,N-di(4 -methoxyphenyl)amino]-9,9'-spirobifluorene), PEDOT, one of PEDOT:PSS, P3HT, P3OHT, P3ODDT, NiOx or CuSCN.

The material of the modification layer is the aforementioned compound (C)n-L-(M)m. In the hole transport functional layer 12, the mass ratio of the compound (C)n-L-(M)m in the modification layer material to the hole transport layer material is 0.01%-99.9%;

The thickness of the hole-transporting functional layer 12 is 1-50 nm.

In step 3, the perovskite precursor solution is coated on the hole transport functional layer 12 away from the substrate 11 by any one of the processing methods of spin coating, blade coating, slit coating, spray coating, printing, and vacuum deposition. One side of the surface, thereby forming a perovskite absorbing layer 14.

Specifically, the general chemical formula of the perovskite absorbing layer 14 is ABX ₃ , wherein A is a monovalent metal cation or an organic cation, which can be selected from: CH ₃ NH ₃ , C ₄ H ₉ NH ₃ , NH ₂ =CHNH _2. At least one of Cs; B is a divalent metal cation, which can be selected from at least one of Pb and Sn; X is a monovalent anion, which can be selected from halogen elements such as Cl, Br or I, SCN-, etc. At least one or more of the pseudohalogens, such as multiple X ions, the total ratio of which satisfies the general chemical formula of the composition of the perovskite absorbing layer 14 . In order to achieve better absorption of sunlight, the thickness range of the perovskite absorbing layer 14 can be 200-5000nm;

In step 4, electron transport is prepared on the surface of the perovskite absorbing layer 14 away from the modified layer by vacuum deposition, spin coating, doctor blade coating, slit coating, spray coating, printing, ALD and other processing methods. Layer 15, the electron transport layer 15 has a thickness in the range of 1-150 nm.

In step five, prepare a TCO layer on the surface of the electron transport layer 15 away from the perovskite absorbing layer 14, and then use The metal electrode layer is prepared by evaporation, printing, electroplating, silk screen and other processing methods. The TCO layer and the metal electrode layer form the top electrode 16. The TCO layer is a transparent conductive film, which can be fluorine-doped tin oxide (FTO) , indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), etc. The material used for the metal electrode can be selected from one or more of metal materials such as Ag, Au, Cu, Al, Ni, C material, and polymer conductive material. The thickness of the top electrode 16 is 0.1 μm-50 μm.

Step 1: providing a substrate 11;

Specifically, a TCO layer is prepared on a transparent battery substrate to obtain a substrate 11 .

Specifically, firstly, the material of the hole transport layer is dissolved in a solvent to obtain a solution 1, and the material of the modification layer is dissolved in a solvent to obtain a solution 2, and then the solution 1 and the solution 2 are mixed to obtain a mixed solution, and then the mixed solution is used The hole transport functional layer 12 is formed on the surface of the substrate 11 by spin coating, spray coating or soaking. The solvent is selected from at least one of amides, alcohols, esters, ketones, ethers or sulfones/sulfoxides.

The material of the modification layer is the aforementioned compound (C)n-L-(M)m.

In the hole transport functional layer 12, the mass ratio of the compound (C)n-L-(M)m in the modification layer material to the hole transport layer material is 0.01%-99.9%;

The thickness of the hole transport functional layer 12 is 0.1-50 nm.

Specifically, the perovskite precursor solution is coated on a side of the hole transport functional layer 12 away from the substrate 11 by any one of the processing methods of spin coating, blade coating, slit coating, spray coating, printing, and vacuum deposition. side surface, thereby forming the perovskite absorbing layer 14.

Specifically, the perovskite precursor solution contains metal halides (the metal halides contain at least one of Pb, Cs, Rb, and K), formamidine halide salts, methylamine halide salts, etc. Organic amine salts, other organic and inorganic additives. The perovskite precursor liquid needs to adopt methods such as heating, gas phase method, anti-solvent method, vacuum desolventization, etc. to generate the perovskite absorbing layer 14 on the modified layer.

Specifically, the electron transport layer 15 is prepared on the surface of the perovskite absorbing layer 14 away from the modified layer by vacuum deposition, spin coating, doctor blade coating, slit coating, spray coating, printing, ALD and other processing methods. , the thickness of the electron transport layer 15 is in the range of 1-150 nm.

When the hole-transporting functional layer 12 of the third structure is applied in a solar cell, the specific preparation method is as follows:

Step 1: providing a substrate 11;

Step 4: Prepare an electron transport layer 15 on the surface of the perovskite absorption layer 14 away from the hole transport functional layer 12;

In step 2, the compound (C)n-L-(M)m is first dissolved in solvents such as amides, alcohols, esters, ketones, ethers or sulfones/sulfoxides to form a concentration of 0.1mM- 1M solution; then use any one of spin coating, scrape coating, soaking, slit coating, spray coating, printing, vacuum deposition, and film drawing to coat the solution on the TCO layer away from the transparent One side surface of the battery substrate to form a hole transport functional layer 12 .

The thickness of the hole-transporting functional layer 12 is 0.1-30 nm.

In step 3, the perovskite precursor solution is coated on the hole transport functional layer 12 away from the TCO by any one of the processing methods of spin coating, blade coating, slit coating, spray coating, printing, and vacuum deposition. One side surface of the layer, thereby forming the perovskite absorbing layer 14.

Specifically, the perovskite precursor solution contains metal halides (the metal halides contain at least one of Pb, Cs, Rb, and K), formamidine halide salts, methylamine halide salts, etc. Organic amine salts, other organic and inorganic additives. The perovskite precursor solution needs to be heated, gas phase method, anti-solvent method, vacuum solvent removal and other methods to form the perovskite absorption layer 14 on the hole transport functional layer 12 .

In step 4, vacuum deposition, spin coating, doctor blade coating, slit coating, spray coating, printing, ALD and other processing methods are applied on the surface of the perovskite absorption layer 14 away from the hole transport functional layer 12 An electron transport layer 15 is prepared on it, and the thickness of the electron transport layer 15 is in the range of 1-150 nm.

In step five, prepare a TCO layer on the surface of the electron transport layer 15 away from the perovskite absorbing layer 14, and then use The metal electrode layer is prepared by evaporation, printing, electroplating, silk screen and other processing methods. The TCO layer and the metal electrode layer form the top electrode 16. The TCO layer is a transparent conductive film, which can be fluorine-doped tin oxide (FTO) , indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), etc. The material used for the metal electrode can be selected from one or more of Ag, Au, Cu, Al, Ni and other metal materials, C material, polymer conductive material, and the thickness of the top electrode 16 is 0.1 μm-50 μm.

Step 1: providing a substrate 11;

Specifically, firstly, the compound (C)n-L-(M)m is dissolved in solvents such as amides, alcohols, esters, ketones, ethers or sulfone/sulfoxides to prepare a concentration of 0.1mM-1M solution; then adopt spin coating, scrape coating, soaking, slit coating, spray coating, printing, vacuum deposition, film drawing in any processing method to coat the solution on the TCO layer away from the transparent battery lining One side surface of the bottom, thereby forming the hole transport function layer 12.

The thickness of the hole-transporting functional layer 12 is 0.1-30 nm.

Specifically, the perovskite precursor solution is coated on the hole transport functional layer 12 away from the TCO layer by any one of the processing methods of spin coating, blade coating, slit coating, spray coating, printing, and vacuum deposition. One side surface, thereby forming the perovskite absorbing layer 14.

Step 4: preparing an electron transport layer 15 on the surface of the perovskite absorption layer 14 away from the hole transport functional layer 12;

Specifically, it is prepared on the surface of the perovskite absorbing layer 14 away from the hole transport functional layer 12 by vacuum deposition, spin coating, doctor blade coating, slit coating, spray coating, printing, ALD and other processing methods. The electron transport layer 15, the thickness range of the electron transport layer 15 is 1-150nm.

As shown in FIG. 2 , the present application provides a tandem solar cell, which includes an upper cell 21 and a lower cell 22 with a TCO layer between the upper cell 21 and the lower cell 22 . The lower cell 22 may be a silicon-based cell, and the TCO layer is laminated with the hole transport functional layer of the aforementioned perovskite solar cell. Various parameters of the upper battery 21 can refer to the aforementioned solar battery.

Example

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

Example 1

The preparation method of the solar cell of the present embodiment comprises the following steps:

Preparation of Substrate 11

An ITO layer is deposited on the glass substrate by PVD method, and the thickness of the ITO layer is 150 nm.

Preparation of the hole transport layer

On the surface of the ITO layer facing away from the glass substrate, a nickel oxide layer, that is, a hole transport layer, is prepared by PVD sputtering. The specific process parameters are 99.99% Ni target material, and the deposition pressure is <2×10-4Pa, The power is 50-1000W, the _O2 partial pressure is about 3%-20%, and the thickness of the hole transport layer is 20nm.

Prepare the finishing layer

First, 2,2'-bithiophene-5-carboxylic acid (abbreviated as 2TA, derived from Aladdin, with a purity of 96%) was dissolved in isopropanol to prepare a 50 mM 2TA solution, and then the 2TA solution was uniformly coated by spin coating. coated on the surface of the hole transport layer facing away from the substrate 11 to form a 2TA modified layer with a thickness of 10 nm.

Preparation of perovskite absorber layer 14

The perovskite absorption layer 14 is prepared on the surface of the modification layer away from the hole transport layer by two-step spin coating. Specifically, first prepare the perovskite precursor solution, the composition of the perovskite precursor solution is prepared according to the ratio of Cs _0.05 FA _0.80 MA _0.15 Pb(I _0.85 Br _0.15 ) ₃ , and then spin-coat the The perovskite precursor solution is evenly coated on the surface of the modification layer facing away from the hole transport layer, and then heated at a temperature of 150° C. to form the perovskite absorbing layer 14 with a thickness of 500 nm .

Preparation of electron transport layer 15

Prepare a C60 layer on the surface of the perovskite absorbing layer 14 away from the modified layer by thermal evaporation processing method, and then prepare _SnO2 on the surface of the side of the C60 layer away from the perovskite absorbing layer 14 by ALD processing method layer, the thickness of the C60 layer is 10 nm, the thickness of the SnO ₂ layer is 10 nm, and the C60 layer and the SnO ₂ layer form the composite electron transport layer 15.

Preparation of the upper electrode

On the side surface of electron transport layer 15 away from described perovskite absorption layer 14, adopt PVD method to deposit ITO layer, the thickness of described ITO layer is 150nm, then on one side of described ITO layer away from described electron transport layer 15 Silver paste was evaporated on the side surface to form a silver electrode, and the thickness of the silver electrode was 200 nm.

The performance of the solar cell is shown in Table 1.

Example 2

The preparation method of the tandem solar cell of this embodiment includes the following steps:

The lower cell is a heterojunction silicon substrate cell,

Composite layer preparation

A PVD process is used to prepare an ITO composite layer on the light-incident side of the heterojunction silicon-based cell, and the thickness of the composite layer junction should be 50 nm.

Prepare the battery

Step 1: preparing a hole transport layer on the ITO composite layer, the hole transport layer is a nickel oxide hole transport layer, and the nickel oxide is prepared by PVD sputtering. 99.99% Ni target material, deposition pressure <2×10-4Pa, power 50-1000W, O ₂ partial pressure about 3%-20%, nickel oxide hole transport layer thickness 20nm.

Step 2: Prepare a modified layer of 2,2'-bithiophene-5-carboxylic acid (abbreviated as 2TA, derived from Aladdin, with a purity of 96%) on the surface of the hole transport layer facing away from the ITO composite layer. Specifically, 2TA was first dissolved in isopropanol to prepare a 50 mM 2TA solution, and then the 2TA solution was evenly coated on the surface of the hole transport layer facing away from the substrate 11 by spin coating, Thus, a 2TA modified layer was formed with a thickness of 10 nm.

Step 3: Prepare the perovskite absorbing layer 14 on the surface of the modification layer facing away from the hole transport layer by two-step spin coating. Specifically, first prepare the perovskite precursor solution, the composition of the perovskite precursor solution is prepared according to the ratio of Cs _0.05 FA _0.80 MA _0.15 Pb(I _0.85 Br _0.15 ) ₃ , and then spin-coat the The perovskite precursor solution is evenly coated on the surface of the modification layer facing away from the hole transport layer, and then heated at a temperature of 150° C. to form the perovskite absorbing layer with a thickness of 500 nm.

Step 4: Prepare a C60 layer on the surface of the perovskite absorbing layer away from the modified layer by thermal evaporation processing method, and then prepare SnO on the surface of the side of the C60 layer away from the perovskite absorbing layer by ALD processing method ₂ layers, the thickness of the C60 layer is 10nm, and the thickness of the SnO ₂ layer is 10nm.

Step 5: Deposit an ITO layer on the surface of the _SnO2 layer away from the perovskite absorbing layer by PVD method, the thickness of the ITO layer is 150nm, and then place the ITO layer away from the electron transport layer One side surface of 15 is vapor-deposited with silver paste to form a silver electrode, and the thickness of the silver electrode is 200nm.

Step 6: Prepare an Ag back electrode with a thickness of 200 nm on the surface of the heterojunction silicon base cell facing away from the composite layer by thermal evaporation.

The performance parameters of the tandem solar cell are shown in Table 1.

Example 3

The difference between Example 3 and Example 2 lies in the modification layer. The modification layer in Example 3 is 2,2'-bithiophene-5-carboxylate potassium salt (2TAK for short) modification layer with a thickness of 10 nm.

The preparation method of the 2TAK is: dissolve 1eq of 2TA in DMSO and other solvents, slowly add potassium hydroxide ethanol solution (0.5M in 10% ethanol) dropwise at 100°C, adjust the pH to 7.0, and stir at the same temperature Under the reaction 6h. After the reaction, filter under reduced pressure, wash the filter cake with cold methanol, collect the filter cake, and freeze-dry for 36 hours or vacuum-dry to obtain 2TAK. ¹ H NMR (DMSO-d6, 400MHz) δ (ppm): 7.12 (dd, J = 6.8Hz, J = 4.8Hz, 1H), 7.33 (d, J = 5.2Hz 1H), 7.47 (d, J = 4.8 Hz, 1H), 7.61 (d, J=6.8Hz, 1H).

The performance of the solar cell is shown in Table 1.

Example 4

The difference between embodiment 4 and embodiment 2 is the modification layer. The modification layer in embodiment 4 is naphthalene-2-sulfonic acid potassium salt (abbreviated as NSK, derived from Bailingwei, and the purity is 99%) modification layer, and the thickness is 10nm .

The performance of the solar cell is shown in Table 1.

Example 5

The difference between embodiment 5 and embodiment 2 is the modification layer. The modification layer in embodiment 5 is 6-amino-2-naphthalenesulfonate potassium (ANSK for short, derived from Bailingwei, and the purity is 95%) modification layer, the thickness 10nm.

The performance of the solar cell is shown in Table 1.

Example 6

The difference between embodiment 6 and embodiment 2 is the modification layer. The modification layer in embodiment 6 is 5-amino-2-benzothiophene carboxylate potassium (abbreviated as NBTAK, derived from Bailingwei, with a purity of 95%) modification layer , with a thickness of 10nm.

The performance of the solar cell is shown in Table 1.

Example 7

The difference between Example 7 and Example 2 lies in the modification layer. The modification layer in Example 7 is potassium 6-methoxy-benzo[B]thiophene-2-carboxylate (abbreviated as OBTAK, derived from BIT, purity 96%) modified layer with a thickness of 10nm.

The performance of the solar cell is shown in Table 1.

Example 8

The difference between Example 8 and Example 2 lies in the modification layer. The modification layer in Example 8 is 4-pyridine propionate potassium (abbreviated as PPK, derived from Behringwei, with a purity of 95%), with a thickness of 10 nm.

The performance of the solar cell is shown in Table 1.

Example 9

The difference between embodiment 9 and embodiment 2 is the modification layer. The modification layer in embodiment 9 is 9H-fluorene-9-methanesulfonate potassium (abbreviated as FSK, derived from Sigma-Aldrich, with a purity of 99%) modification layer , with a thickness of 10nm.

The performance of the solar cell is shown in Table 1.

Example 10

The tandem solar cell of this embodiment differs from that of Embodiment 2 only in the hole-transporting functional layer 12. Compared with the hole-transporting functional layer 12 in Embodiment 10 and the hole-transporting functional layer 12 in Embodiment 2, There is only a modification layer without a hole transport layer, the modification layer is an O-3TAK layer, and the thickness of the modification layer is 30 nm.

The preparation method of the O-3TAK is:

Succinic anhydride (10.0 mmol, 1.0 equiv) and 20 mL of anhydrous DCM were successively added to the two-necked flask, the mixed solution was stirred, cooled to 0°C, anhydrous AlCl ₃ (12.0 mmol, 1.2 equiv) was added in batches, and the reaction was continued for 2 h. Slowly add bithiophene dropwise. After the dropwise addition, the temperature rises to room temperature and continues the reaction until the reaction is complete. The reaction mixture was poured into 30m of ice water, and the pH was adjusted to 2 with 2N HCl. The aqueous phase was extracted three times with DCM, the organic phases were combined, dried over anhydrous sodium sulfate, filtered, the solvent was removed by spin, and the crude product was separated by column chromatography (PE/EA=2:1, with 0.3% CH ₃ COOH) to obtain the pure product 5a2. Yield 69%. ¹ H NMR (DMSO-d6) δ (ppm): 2.56 (t, J = 6.7Hz, 2H), 3.18 (t, J = 6.7Hz, 2H), 6.67 (d, J = 3.6Hz, 1H), 6.97 (d, J=3.6Hz, 1H), 6.98(dd, J=4.7Hz, J=3.6Hz, 1H), 7.09(d, J=3.6Hz, 1H), 7.17(d, J=4.7Hz, 1H ), 12.2(bs,1H).

Add 5a2 (65.2mmol, 1.0equiv) and 250mL of diethylene glycol to the two-necked flask at one time, stir to dissolve. The mixed solution was cooled to 0° C., and hydrazine hydrate (2.19 equiv, 143 mmol) and KOH (2.19 equiv, 143 mmol) were added to the reaction flask. The reaction mixture was heated to reflux, and the reaction was continued for 4h. The reaction solution was cooled to room temperature, and the pH was adjusted to pH=7 with 2N HCl. Suction filtration, the filter cake was washed several times with cold methanol solution, and the filter cake was collected. The filter cake can also be purified by methanol recrystallization. The pure product 5b2 was obtained. Yield 75%. ¹ H NMR (CDC1 ₃ ) δ (ppm): 1.39-1.72 (m, 2H), 2.36 (t, 2H), 2.79 (t, 2H), 6.67 (d, J=3.6Hz, 1H), 6.97 (d ,J=3.6Hz,1H),6.98(dd,J=4.7Hz,J=3.6Hz,1H),7.09(d,J=3.6Hz,1H),7.17(d,J=4.7Hz,1H), 10.7(bs,1H).

Add 5b2 (1 equ.) and 30 mL of anhydrous DMC to the reaction flask, stir and lower the temperature to 0°C. Add NBS (1.2equ.) in batches, warm up to room temperature after the addition, and react in the dark for 8 hours. The reaction mixture was poured into water, extracted three times with ether, and the organic phases were combined. Dry over anhydrous Na ₂ SO ₄ , filter, and spin off the solvent to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 9:1) to obtain the pure product 5c2. Yield 81%. ¹ H NMR (CDC1 ₃ ) δ (ppm): 1.39-1.72 (m, 2H), 2.36 (t, 2H), 2.79 (t, 2H), 6.67 (m, J = 3.6Hz, 1H), 6.97 (d , J=3.6Hz, 1H), 6.98 (dd, J=4.7Hz, J=3.6Hz, 1H), 7.09 (d, J=3.6Hz, 1H), 10.7 (bs, 1H).

Add 2-methoxy-5-boronic acid thiophene (1equiv), 5c2 (1equiv), Na ₂ CO ₃ (2equiv) sequentially into the Schleck tube, and ventilate. Pd(PPh ₃ )4 (5mol%) was added into the glove box. The solvent acetonitrile (20 mL) was then added and heated to 80° C. for 12 h. After the reaction was complete, it was lowered to room temperature, poured into water, the aqueous phase was extracted with dichloromethane (DCM), the organic phases were combined, dried over anhydrous Na2SO4, filtered, and the solvent was spin-off to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 9:1) to obtain the product 5d2. Yield 87%. ¹ H NMR (CDCl ₃ ) δ (ppm): 1.35-1.78 (m, 2H), 2.36 (t, 2H), 2.79 (t, 2H), 3.70 (s, 3H), 6.68 (d, J = 3.6Hz ,1H),6.97(d,J=3.6Hz,1H),6.99(d,J=3.7Hz,1H),7.02(dd,J=3.7Hz,J=5.1Hz,1H),7.05(d,J= 3.7Hz, 1H), 7.15(d, J=3.6Hz, 1H), 7.19(d, J=5.1Hz, 1H), 10.7(bs, 1H).

Dissolve 1eq of 5d2 in a solvent such as DMSO, slowly add potassium hydroxide ethanol solution (0.5M in 10% ethanol) dropwise at 100°C, adjust the pH to 7.0, and react for 30min-6h under stirring at the same temperature. After the reaction, filter under reduced pressure, wash the filter cake with cold methanol, collect the filter cake, and freeze-dry for 36 hours or vacuum-dry to obtain O-3TAK. 1H NMR(CDCl3)δ(ppm):1.35-1.78(m,2H),2.36(t,2H),2.79(t,2H),3.70(s,3H),6.68(d,J＝3.6Hz,1H ), 6.97(d, J=3.6Hz, 1H), 6.99(d, J=3.7Hz, 1H), 7.02(dd, J=3.7Hz, J=5.1Hz, 1H), 7.05(d, J=3.7Hz , 1H), 7.15 (d, J=3.6Hz, 1H), 7.19 (d, J=5.1Hz, 1H).

The performance parameters of the tandem solar cell are shown in Table 1.

Example 11

The tandem solar cell of this embodiment differs from that of Embodiment 2 only in the hole-transporting functional layer 12. Compared with the hole-transporting functional layer 12 in Example 11 and the hole-transporting functional layer 12 in Example 2, There is only a modification layer without a hole transport layer, the modification layer is a 3TAK layer, and the thickness of the modification layer is 30 nm.

The preparation method of the 3TAK is:

Succinic anhydride (10.0 mmol, 1.0 equiv) and 20 mL of anhydrous DCM were successively added to the two-necked flask, the mixed solution was stirred, cooled to 0°C, anhydrous AlCl ₃ (12.0 mmol, 1.2 equiv) was added in batches, and the reaction was continued for 2 h. Slowly add trithiophene dropwise. After the dropwise addition, the temperature is raised to room temperature and the reaction is continued until the reaction is complete. The reaction mixture was poured into 30m of ice water, and the pH was adjusted to 2 with 2N HCl. The aqueous phase was extracted three times with DCM, the organic phases were combined, dried over anhydrous sodium sulfate, filtered, the solvent was removed by spin, and the crude product was separated by column chromatography (PE/EA=2:1, with 0.3% CH ₃ COOH) to obtain the pure product 5a3.

Succinic anhydride (10.0 mmol, 1.0 equiv) and 20 mL of anhydrous DCM were successively added to the two-necked flask, the mixed solution was stirred, cooled to 0°C, anhydrous AlCl ₃ (12.0 mmol, 1.2 equiv) was added in batches, and the reaction was continued for 2 h. Slowly add 5a3 dropwise. After the dropwise addition, the temperature is raised to room temperature and the reaction is continued until the reaction is complete. The reaction mixture was poured into 30m of ice water, and the pH was adjusted to 2 with 2N HCl. The aqueous phase was extracted three times with DCM, the organic phases were combined, dried over anhydrous sodium sulfate, filtered, the solvent was removed by spin, and the crude product was separated by column chromatography (PE/EA=2:1, with 0.3% CH ₃ COOH) to obtain the pure product 5b3.

Succinic anhydride (10.0 mmol, 1.0 equiv) and 20 mL of anhydrous DCM were successively added to the two-necked flask, the mixed solution was stirred, cooled to 0°C, anhydrous AlCl ₃ (12.0 mmol, 1.2 equiv) was added in batches, and the reaction was continued for 2 h. Slowly add 5b3 dropwise. After the dropwise addition, the temperature is raised to room temperature and the reaction is continued until the reaction is complete. The reaction mixture was poured into 30m of ice water, and the pH was adjusted to 2 with 2N HCl. The aqueous phase was extracted three times with DCM, the organic phases were combined, dried over anhydrous sodium sulfate, filtered, the solvent was removed by spin, and the crude product was separated by column chromatography (PE/EA=2:1, with 0.3% CH ₃ COOH) to obtain the pure product 5c3.

Add 2,5-diboronic acid thiophene (1equiv), 5c3 (2equiv) and Na ₂ CO ₃ (2equiv) sequentially into the Schleck tube, and ventilate. Pd(PPh ₃ )4 (5mol%) was added into the glove box. The solvent acetonitrile (20 mL) was then added and heated to 80° C. for 12 h. After the reaction was complete, it was lowered to room temperature, poured into water, the aqueous phase was extracted with dichloromethane (DCM), the organic phases were combined, dried over anhydrous Na2SO4, filtered, and the solvent was spin-off to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 9:1) to obtain the product 5d3. Yield 90%. ¹ H NMR(CDCl ₃ )δ(ppm):1.35-1.78(m,4H),2.36(t,4H),2.79(t,4H), 6.68(d,J=3.6Hz,1H),6.97(d ,J=3.6Hz,7H),6.99(d,J=3.7Hz,2H),7.05(d,J=3.7Hz,2H),7.15(d,J=3.6Hz,2H),10.7(bs,1H ).

Dissolve 1eq of 5d3 in a solvent such as DMSO, slowly add potassium hydroxide ethanol solution (0.5M in 10% ethanol) dropwise at 100°C, adjust the pH to 7.0, and react for 30min-6h under stirring at the same temperature. After the reaction, filter under reduced pressure, wash the filter cake with cold methanol, collect the filter cake, and freeze-dry for 36 hours or vacuum-dry to obtain 3TAK. 1H NMR(CDCl3)δ(ppm):1.35-1.78(m,4H),2.36(t,4H),2.79(t,4H),6.68(d,J＝3.6Hz,1H),6.97(d,J = 3.6Hz, 7H), 6.99 (d, J = 3.7Hz, 2H), 7.05 (d, J = 3.7Hz, 2H), 7.15 (d, J = 3.6Hz, 2H).

The performance parameters of the tandem solar cell are shown in Table 1.

Example 12

The tandem solar cell of this embodiment differs from that of Embodiment 2 only in the hole transport functional layer 12. Compared with the hole transport functional layer 12 of Embodiment 12, the hole transport functional layer 12 in Embodiment 2, There is only a modification layer without a hole transport layer. The modification layer is a triphenylamine benzyl dipotassium phosphate layer (TPAPK for short, purchased from Bide, with a purity of 95%), and the thickness of the modification layer is 30nm.

The performance parameters of the tandem solar cell are shown in Table 1.

Example 13

The tandem solar cell of this embodiment differs from that of Example 2 only in the hole-transporting functional layer 12. Compared with the hole-transporting functional layer 12 in Example 13 and the hole-transporting functional layer 12 in Example 2, There is only a modification layer without a hole transport layer, the modification layer is a PyAK layer, and the thickness of the modification layer is 30 nm.

The preparation method of described PyAK is:

6a (1.0 equiv), Bu4NHSO4 (0.24 equiv), and 130 mL of benzene were sequentially added to the two-necked flask, and 50% NaOH aqueous solution (25 mL) was added dropwise with stirring. After stirring for 5 min, the desired bromoester compound EtOOC(CH ₂ ) ₃ Br (2.1 equiv) was added dropwise. After the dropwise addition, the temperature was raised to 60° C. to continue the reaction for 4 h. Cool at room temperature, wash the organic phase with water several times, and spin off the solvent. Column chromatography (PE/ethyl acetate 9:1) gave product 6b.

Add 6b (3.82mmol), 10% KOH aqueous solution (45mL) and ethanol (20mL) to the two-necked flask successively, heat to reflux for 20min, cool to 0°C, and adjust the pH to 7 with 2N HCl. Suction filtration, the filter cake was washed several times with cold methanol solution, and the filter cake was collected. The filter cake can also be purified by methanol recrystallization. Get PyAK. 1H NMR (CDCI3) δ (ppm): 1.35 (m, 2H), 2.25 (t, 2H), 4.20 (t, 2H), 7.00-7.10 (AB system, J = 5.2Hz, 4H).

The performance parameters of the tandem solar cell are shown in Table 1.

Example 14

The tandem solar cell of this embodiment differs from that of Embodiment 2 only in the hole-transporting functional layer 12. Compared with the hole-transporting functional layer 12 in Embodiment 14, There is only a modification layer without a hole transport layer, the modification layer is a C2TAK layer, and the thickness of the modification layer is 30 nm.

The preparation method of the C2TAK is:

Under anhydrous and oxygen-free conditions, 7a (1.0 equiv, 5.05 mmol) and anhydrous THF (20 mL) were sequentially added into the reaction flask, and the gas was exchanged three times. Stir and cool to -20°C, slowly add BuLi (1.6M in hexane, 1.01 equiv, 5.12mmol) dropwise. After the dropwise addition, warm up to room temperature and react for 1 h, then add the reaction mixture dropwise into a THF (10 mL) solution of Br(CH ₂ ) ₃ Br (1.0 equiv, 5.05 mmol), and keep the temperature of the reaction system at 0°C during the dropwise addition . After the dropwise addition, it was raised to room temperature and reacted for 1 h. The reaction mixture was poured into water, extracted three times with ether, and the organic phases were combined. Dry over anhydrous Na2SO4, filter, and spin off the solvent to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 9:1) to obtain pure product 7b.

7b (1.01equiv, 1.22mmol), 18-Crown-6 (0.3equiv, 0.37mmol), KCN (7.55equiv, 9.22mmol) and acetonitrile (15mL) were sequentially added to the three-necked flask, stirred, and heated to reflux for 10h. After the reaction was complete, cool to room temperature, pour the reaction mixture into water, and wash with ether several times. The aqueous phase was adjusted to pH 7 with 2N HCl. Combine the organic phases. Dry over anhydrous Na ₂ SO ₄ , filter, and spin off the solvent to obtain a crude product. The obtained crude product was separated by column chromatography (PE/ethyl acetate 8:2) to obtain pure product 7c.

7c (1.01equiv, 0.62mmol), KOH (34.5equiv, 21.40mmol), ethanol:water (2.5:1, 15mL) were sequentially added into the three-neck flask, stirred, and heated to reflux for 3h. After the reaction was complete, cool to room temperature, pour the reaction mixture into water, and extract with ether several times. The aqueous phase was adjusted to pH 7 with 2N HCl. Suction filtration, the filter cake was washed several times with cold methanol solution, and the filter cake was collected. The filter cake can also be purified by methanol recrystallization. Get C2TAK. 1H NMR (CDCI3) δ (ppm): 1.50 (m, 2H), 2.30 (t, 2H), 3.51 (t, 1H), 7.05-7.15 (AB system, J = 5.2Hz, 4H).

The performance parameters of the tandem solar cell are shown in Table 1.

Example 15

The difference between the laminated solar cell of this embodiment and Embodiment 2 is only the hole transport functional layer 12, and the difference between the laminate solar cell of this embodiment and Embodiment 2 is only the hole transport functional layer 12, The preparation method of the hole transport functional layer 12 of embodiment 15 is as follows:

Prepare the hole-transporting functional layer 12 on the ITO composite layer. Specifically, first dissolve Me-4PACz in methanol to obtain solution 1, the concentration of which is 2 mg/mL, and dissolve FAK (refer to the foregoing examples for the preparation method) Solution 2 was obtained in methanol with a concentration of 5 mg/mL, then solution 1 and solution 2 were mixed at a volume ratio of 1:1 to obtain a mixed solution, and then the mixed solution was compounded on the ITO by spin coating The hole transport function layer 12 was formed on the surface of the layer, and its thickness was 30 nm.

The performance parameters of the tandem solar cell are shown in Table 1.

Example 16

The difference between the laminated solar cell of this embodiment and Embodiment 2 is only the hole transport functional layer 12, and the difference between the laminate solar cell of this embodiment and Embodiment 2 is only the hole transport functional layer 12, The preparation method of the hole transport functional layer 12 of embodiment 16 is as follows:

Prepare the hole transport functional layer 12 on the ITO composite layer. Specifically, first dissolve Me-4PACz in methanol to obtain solution 1, the concentration of which is 2 mg/mL, and dissolve C2TAK (refer to the aforementioned examples for the preparation method) Solution 2 was obtained in methanol with a concentration of 5 mg/mL, then solution 1 and solution 2 were mixed at a volume ratio of 1:1 to obtain a mixed solution, and then the mixed solution was compounded on the ITO by spin coating The hole transport function layer 12 was formed on the surface of the layer, and its thickness was 30 nm.

The performance parameters of the tandem solar cell are shown in Table 1.

Comparative example 1

The difference between the tandem solar cell of Comparative Example 1 and Example 2 is only the hole transport functional layer 12. Compared with the hole transport functional layer 12 of Comparative Example 1 and the hole transport functional layer 12 in Example 2, There is only a hole transport layer without a modification layer, and the thickness of the hole transport layer is 30 nm.

The performance parameters of the tandem solar cell are shown in Table 1.

Comparative example 2

The tandem solar cell of this embodiment differs from that of Example 2 only in the hole-transporting functional layer 12. Compared with the hole-transporting functional layer 12 of Comparative Example 2 and the hole-transporting functional layer 12 in Example 2, There is only a hole transport layer without a modification layer, and the hole transport layer is a Me-4PACz layer with a thickness of 30 nm. The performance parameters of the tandem solar cell are shown in Table 1. Table 1 is the performance parameter of each embodiment and the solar cell of comparative example

Summary: Combining Table 1 and Figure 3, it can be seen that the fluorescence emission peaks of the perovskite absorbing layer in Example 2 and Comparative Example 1 are all located at about 754nm, indicating that the modification layer in the hole transport function layer has an important effect on the perovskite absorbing layer. The composition, phase distribution, etc. have little influence, and the fluorescence quantum intensity of the perovskite absorbing layer of Example 1 is significantly higher than that of the perovskite absorbing layer of Comparative Example 1, indicating that the perovskite absorbing layer passivated by the 2TA modified layer absorbs The defects in the layer are significantly reduced, so there is a stronger fluorescence quantum yield, which is conducive to improving the carrier recombination caused by interface defects, thereby improving the efficiency and stability of solar cells.

It can be seen from Table 1 that after the lower interface of the perovskite absorber layer is passivated by the 2TAK layer modification layer, it has a higher open circuit voltage and fill factor, so it has a higher photoelectric conversion performance, and its cell efficiency reaches 25.62% (PCE) , the open circuit voltage is 1.85V, the fill factor is 0.741, and the short circuit current is 18.69mA/cm ² . However, the battery efficiency of Comparative Example 1 is 21.97%, the open circuit voltage is 1.81V, the fill factor is 0.665, and the short circuit current is 18.25mA/cm ² .

In summary, by introducing a modification layer or a modification layer material to passivate the lower interface of the perovskite absorber layer, the loss caused by non-radiative recombination at the interface is greatly reduced, and the interface-modified solar cells all show higher open circuit voltage and fill factor.

Although the embodiments of the present application have been described above, the present application is not limited to the above-mentioned specific embodiments and application fields, and the above-mentioned specific embodiments are only illustrative, instructive, and not restrictive. Those skilled in the art can also make many forms under the enlightenment of this description and without departing from the protection scope of the claims of the application, and these all belong to the protection list of the application.

Claims

A compound, characterized in that, the structural formula of the compound is (C)n-L-(M)m, n≥1, m≥1,

The C structure is selected from at least one of the conjugated structural units of aromatic hydrocarbons and their derivatives or heterocyclic compounds and their derivatives;

L is a chain segment with carboxylate, sulfonate, or phosphate at the end group, and the chain segment is an alkyl chain with 0 to 20 carbon atoms, an alkoxy chain, an ether oxygen chain, a phenyl group, a silyl group, or at least one of the nitrogen-containing fragments;

M is at least one selected from hydrogen, alkali metals, alkaline earth metals or transition metals.
The compound according to claim 1, wherein the C structure is selected from the group consisting of thiophene and its derivatives, thiophene and its derivatives, pyrrole and its derivatives, pyridine and its derivatives, benzene and its derivatives, At least one of fluorene and its derivatives, carbazole and its derivatives, triarylamine and its derivatives.
The compound according to claim 1, wherein the C structure has at least one of the following structures:
The compound according to claim 1, wherein the structural formula of the compound is selected from the following:
A method for preparing the compound according to any one of claims 1 to 4, characterized in that the compound is synthesized by route one, route two, route three or route four, wherein,

Route 1:

Add AlCl3 in batches to the solution containing succinic anhydride, after the reaction, slowly add the aromatic hydrocarbon containing the C structure or its derivatives or heterocyclic compound or its derivatives dropwise, and obtain compound 1a after the reaction is completed;

Compound 1a is reduced by hydrazine hydrate under alkaline conditions, and the pH is adjusted after the reaction is completed, thereby obtaining Compound 1b;

Wherein the structural formula of compound 1a is:

The structural formula of compound 1b is:

Route two:

Under alkaline conditions, add EtOOC(CH 2 ) n Br to the solution of the aromatic hydrocarbon or its derivatives or heterocyclic compounds or its derivatives containing the C structure to carry out the alkylation reaction at the N atom position, after the reaction is complete Compound 2a is obtained;

The solution of compound 2a is subjected to ester hydrolysis reaction under alkaline conditions, and the pH is adjusted after the reaction to obtain compound 2b;

Wherein the structural formula of compound 2a is:

The structural formula of compound 2b is:

Route three:

Under anhydrous and oxygen-free alkaline conditions, add Br(CH 2 ) n Br to the solution containing the aromatic hydrocarbon or its derivatives or heterocyclic compounds or its derivatives containing the C structure to carry out sp3 C atom of cyclopentadiene unit The alkylation reaction of the position, the compound 3a is obtained after the reaction;

Compound 3a reacts with a cyanide reagent to obtain compound 3b after the reaction;

Compound 3b is subjected to cyano hydrolysis under alkaline conditions, and after the reaction, acid is used to adjust the pH to obtain compound 3c;

Wherein, the structural formula of compound 3a is:

The structural formula of compound 3b is:

The structural formula of compound 3c is:

Route 4:

In the solution containing A-COOH, add dropwise in the solution containing alkali, adjust its pH after the reaction, continue the reaction, and obtain the organometallic salt product A-COOM;

where A is
one of

M is metal.
The preparation method according to claim 5, characterized in that, in the route one,

Mix and stir succinic anhydride and anhydrous dichloromethane to obtain mixed liquid 1, and cool it, add AlCl3 in batches to the mixed liquid 1 for reaction, and then slowly add aromatic hydrocarbon or its derivatives containing C structure dropwise or a solution of a heterocyclic compound or a derivative thereof, after the dropwise addition, continue to react until the reaction is complete to obtain a mixed solution 2, pour the mixed solution 2 into ice water, then adjust the pH, then extract the aqueous phase, and combine The organic phase was then dried, filtered, and the solvent was spun off and separated to obtain compound 1a;

Mix and dissolve compound 1a and diethylene glycol to obtain a mixed solution 3, and cool it down, add hydrazine hydrate and potassium hydroxide to the mixed solution 3, heat and react to obtain a mixed solution 4, adjust the mixed solution 4 pH, and then filtered and recrystallized to obtain compound 1b.
The preparation method according to claim 6, characterized in that, in the route one, after the mixed solution is cooled to 0°C, anhydrous AlCl3 is added therein and reacted for 1-2h;

Pour the mixed solution 2 into ice water, and then adjust its pH so that the pH is 2, then extract the aqueous phase with dichloromethane, and combine the organic phases;

Cool the mixed solution 3 to 0°C, then add hydrazine hydrate and potassium hydroxide to the mixed solution 3, heat the reaction to reflux, continue the reaction for 2-6 hours, and then lower the reaction solution to room temperature to obtain a mixed solution Fourth, adjust the pH of the mixed solution to 2 or 7, and then undergo suction filtration and recrystallization to obtain 1b.
The preparation method according to claim 5, characterized in that, in the route two,

Add Bu 4 NHSO 4 and benzene in sequence to the solution of aromatic hydrocarbons or their derivatives or heterocyclic compounds or their derivatives containing C structure, stir evenly, add NaOH aqueous solution dropwise, after stirring, continue to drop EtOOC (CH 2 ) nBr , after the dropwise addition is completed, the temperature is raised to continue the reaction to obtain the mixed solution 5, and then the organic phase is washed several times with water, the solvent is removed by spin, and the product compound 2a is obtained by separation;

Potassium hydroxide aqueous solution and ethanol were sequentially added to compound 2a, heated to react to obtain mixed solution 6, the pH of the mixed solution 6 was adjusted, and then filtered and recrystallized to obtain 2b.
The preparation method according to claim 8, characterized in that, in the route two

Add Bu 4 NHSO 4 and benzene in sequence to the solution of aromatic hydrocarbons or their derivatives or heterocyclic compounds or their derivatives containing C structure, stir evenly, add NaOH aqueous solution dropwise, after stirring, continue to drop bromoester in it EtOOC(CH 2 )nBr-like compound, after the dropwise addition is completed, the temperature is raised to 50-80°C, and the reaction is continued to obtain the mixed solution 5, the mixed solution 5 is cooled to room temperature, the organic phase is washed several times with water, the solvent is removed, and the column Chromatographic separation obtains the product compound 2a;

Add potassium hydroxide aqueous solution and ethanol in sequence to compound 2a, heat to reflux, and then cool to 0°C to obtain mixed solution 6, adjust the pH of the mixed solution 6 to 2 or 7, then undergo suction filtration and recrystallization to obtain compound 2b .
The preparation method according to claim 5, characterized in that, in the route three,

Add tetrahydrofuran to the solution of aromatic hydrocarbons or their derivatives or heterocyclic compounds or their derivatives containing C structure, then ventilate, stir and cool, slowly add BuLi dropwise to it, after the dropwise addition, react to obtain a mixed solution 7. Add the mixed solution 7 dropwise to the tetrahydrofuran solution containing Br(CH 2 ) n Br. After the dropwise addition, the mixed solution 8 is obtained. Pour the mixed solution 8 into water for extraction, then combine the organic phases, and then dry , filter, spin off the solvent, and separate to obtain compound 3a;

Add 18-crown ether-6, potassium cyanide, and acetonitrile to compound 3a, stir evenly, and heat to react to obtain mixed liquid 9, pour mixed liquid 9 into water, wash, then adjust the pH of the aqueous phase, and then combine the organic phase, and then dried, filtered, spin off the solvent, and separated to obtain compound 3b;

Add potassium hydroxide, ethanol, and water to compound 3b, stir evenly, and heat to react to obtain a mixed liquid 10, pour the mixed liquid 10 into water, extract several times, adjust the pH of the aqueous phase, and then use suction filtration, heavy Crystallization gave the product compound 3c.
The preparation method according to claim 10, characterized in that, in the route three,

Under anhydrous and oxygen-free conditions, tetrahydrofuran is added to the solution of aromatic hydrocarbons containing C structure or their derivatives or heterocyclic compounds or their derivatives, then ventilated, stirred and cooled to -20°C, and BuLi is slowly added dropwise. , after the dropwise addition, rise to room temperature to react to obtain the mixed solution 7, add the mixed solution 7 dropwise to the tetrahydrofuran solution containing Br(CH 2 )nBr, keep the temperature of the reaction system at 0°C during the dropwise addition, after the dropwise addition , rise to room temperature and react to obtain the mixed solution 8, pour the mixed solution 8 into water, extract with ether, then combine the organic phases, then dry, filter, spin off the solvent to obtain a crude product, and the obtained crude product is separated by column chromatography to obtain Compound 3a;

Add 18-crown ether-6, potassium cyanide, and acetonitrile to compound 3a, stir evenly, and heat to reflux reaction to obtain mixed solution 9, cool the mixed solution 9 to room temperature, and pour mixed solution 9 into water , washing with ether, adjusting the pH of the aqueous phase to 7, then combining the organic phases, drying, filtering, and spinning off the solvent to obtain a crude product, which was separated by column chromatography to obtain compound 3b;

Add potassium hydroxide, ethanol and water (2.5:1, 15mL) to compound 3b, stir evenly, and heat to reflux reaction to obtain mixed solution 10; The mixed solution 10 is cooled to room temperature, and it is poured into water, using After extraction with ether several times, the pH of the aqueous phase was adjusted to 2 or 7, and the product compound 3c was obtained by suction filtration and recrystallization.
The preparation method according to claim 5, characterized in that, A-COOH is dissolved in DMSO, and the ethanol solution of metal hydroxide is slowly added dropwise therein to obtain the mixed solution 11, and then the pH of the mixed solution 11 is adjusted , and continue the reaction to obtain the mixed solution 12. After the reaction, the mixed solution 12 is filtered under reduced pressure and dried to obtain the corresponding organometallic salt product A-COOM.
The preparation method according to claim 12, characterized in that, in the route four,

Dissolve A-COOH in DMSO, and slowly drop the ethanol solution of metal hydroxide therein to obtain the mixed solution 11, then adjust the pH of the mixed solution 11 to 7.0, continue the reaction for 0.5-6h, and obtain the mixed solution 12 After the reaction, the mixed solution was vacuum filtered and dried to obtain the corresponding organometallic salt product A-COOM.
Application of a compound described in any one of claims 1-13 in solar cells.
A solar cell, characterized in that it includes a substrate, a hole transport functional layer, a perovskite absorption layer, an electron transport layer and a top electrode that are sequentially stacked from bottom to top;

The hole transport functional layer contains (C)n-L-(M)m;

The (C)n-L-(M)m is the compound (C)n-L-(M)m described in any one of claims 1-4.
The solar cell according to claim 15, wherein the hole transport functional layer is a hole transport layer and a modification layer laminated together, and the hole transport layer and the substrate are laminated together, the The modification layer is laminated with the perovskite absorbing layer.
The solar cell according to claim 16, wherein the modification layer is a (C)n-L-(M)m layer with a thickness of 0.1-30nm;

The thickness of the hole transport layer is 1-150nm.
The solar cell according to claim 15, wherein the hole transport functional layer is a mixture of a hole transport layer material and a modification layer material, and the hole transport functional layer is formed on the surface of the substrate.
The solar cell according to claim 18, wherein the modification layer material comprises compound (C)n-L-(M)m;

In the hole transport functional layer, the mass ratio of compound (C)n-L-(M)m in the modification layer material to the hole transport layer material is 0.01%-99.9%;

The thickness of the hole-transporting functional layer is 0.1-50 nm.
The solar cell according to claim 15, characterized in that the hole transport functional layer is a (C)n-L-(M)m layer with a thickness of 0.1-30 nm.
The solar cell according to any one of claims 15-20, wherein when the solar cell is a single cell, the substrate includes a transparent cell substrate and a TCO layer laminated together, and the TCO layer laminated together with the hole transport functional layer.
The solar cell according to any one of claims 15-20, wherein when the solar cell is a stacked cell, the substrate includes a silicon-based cell and a TCO layer stacked together, and the TCO layer laminated together with the hole transport functional layer.
A method for preparing a solar cell, comprising the steps of:

provide the basis;

preparing a hole transport functional layer on one side surface of the substrate;

preparing a perovskite absorbing layer on the surface of the hole transport functional layer away from the substrate;

preparing an electron transport layer on a surface of the perovskite absorption layer away from the hole transport functional layer;

preparing a top electrode on the surface of the side of the electron transport layer away from the perovskite absorbing layer;

The hole transport functional layer contains (C)n-L-(M)m;

The (C)n-L-(M)m is the compound (C)n-L-(M)m described in any one of claims 1-9.
The preparation method according to claim 23, characterized in that the prepared solar cell is the solar cell according to any one of claims 15-22.