阅读说明：本技术 一种含螺[芴-杂环]结构的空穴传输材料及其制备方法和应用 (Hole transport material containing spiro [ fluorene-heterocycle ] structure and preparation method and application thereof ) 是由 尹国辉 许波 董颖 张月成 赵继全 于 2021-09-16 设计创作，主要内容包括：本发明为一种含螺[芴-杂环]结构的空穴传输材料及其制备方法和应用。该材料以氮上连有烃基的螺[芴-9,4’-咪唑啉]-2’,5’-二酮或螺[芴-9,4’-咪唑啉]-2’,5’-二硫酮作为中心核,含甲氧基或甲硫基取代的二苯胺、二苯胺、咔唑、吩噻嗪或吩噁嗪为端基基团,制备中,在三氟乙酸或磺酸化合物作用下,9,10-菲醌类型化合物与脲或脲衍生物反应合成螺[芴-9,4’-咪唑啉]-2’,5’-二酮类型化合物,反应条件温和,制备简便,为这一螺环骨架结构类型化合物的合成提供了新方法。(The invention relates to a hole transport material containing a spiro [ fluorene-heterocycle ] structure, and a preparation method and application thereof. The spiro [ fluorene-9, 4' -imidazoline ] -2 ', 5 ' -dione or spiro [ fluorene-9, 4' -imidazoline ] -2 ', 5 ' -dithione with alkyl connected to nitrogen is used as a central core, and diphenylamine, carbazole, phenothiazine or phenoxazine containing methoxyl or methylthio substitution is used as an end group, in the preparation process, under the action of trifluoroacetic acid or sulfonic acid compounds, 9, 10-phenanthrenequinone type compounds and urea or urea derivatives react to synthesize spiro [ fluorene-9, 4' -imidazoline ] -2 ', 5 ' -dione type compounds, the reaction conditions are mild, the preparation is simple and convenient, and a novel method is provided for the synthesis of the spiro skeleton structure type compounds.)

1. A hole transport material containing a spiro [ fluorene-heterocycle ] structure is characterized in that the chemical structure general formula of the compound is shown as formula I:

wherein X is an oxygen atom or a sulfur atom; r is C1-C12 alkyl; g is any one of the following structural formulas:

2. spiro [ fluorene-containing heterocycles as claimed in claim 1]A hole transport material of structure characterized in that G isR is methyl to obtain the hole transport material with the chemical structure shown as SFHc- (1) or SFHc- (2):

3. the method for producing a spiro [ fluorene-heterocycle ] structure-containing hole transport material according to claim 2, characterized by one of the following two methods:

the method comprises the following steps: the synthesis steps of the SFHc- (1) are as follows:

s1: under the protection of inert gas, adding 2, 7-dibromo-9, 10-phenanthrenequinone, 1, 3-dimethylurea, acid and a first solvent into a reactor with a water separator, and reacting at 100-120 ℃ for 10-12 h to obtain a spiro compound 1;

wherein the mol ratio of the 2, 7-dibromo-9, 10-phenanthrenequinone to the 1, 3-dimethylurea to the acid is 1: 1-3: 1-5, wherein the dosage of the solvent is 2-20 mL of the solvent added in each millimole of 2, 7-dibromo-9, 10-phenanthrenequinone;

the acid is one or more of trifluoroacetic acid or sulfonic acid compounds; the sulfonic acid compound is p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid or camphorsulfonic acid;

s2: under the protection of inert gas, adding a compound 1, 4' -dimethoxydiphenylamine, a strong base, a catalyst and a second solvent into a reactor, and reacting for 10-15 h at 105-115 ℃ to obtain a hole transport material SFHc- (1);

wherein the mol ratio of the compound 1 to the 4,4' -dimethoxydiphenylamine is 1: 2.5-3.5, wherein the molar ratio of the strong base to the catalyst to the compound 1 is 2-6: 0.03 to 2: 1; adding 2-20 mL of a second solvent into each millimole of the compound 1;

the reaction is that the strong base is sodium tert-butoxide or potassium tert-butoxide, the catalyst is tris (dibenzylideneacetone) dipalladium and a substance M, the substance M is tri-tert-butylphosphine or tri-tert-butylphosphine tetrafluoroborate, and the molar ratio of tris (dibenzylideneacetone) dipalladium to the substance M is 0.01-1: 0.02 to 1;

or, the second method, the synthesis steps of the SFHc- (2) are as follows:

under the protection of inert gas, reacting a third solvent, a compound SFHc- (1) and a Lawson reagent at 105-115 ℃ for 9-11 h to obtain a hole transport material SFHc- (2);

the mol ratio of SFHc- (1) to Lawson reagent is 1: 2-4, adding 2-20 mL of a third solvent per millimole of the compound SFHc- (1).

4. The method according to claim 3, wherein the first solvent, the second solvent, and the third solvent are toluene.

5. The method for producing a spiro [ fluorene-heterocycle ] structure-containing hole transport material according to claim 3, wherein the inert gas is argon or nitrogen.

6. A perovskite solar cell is characterized by comprising a transparent conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode in sequence from bottom to top, wherein the hole transport layer is made of any one of the hole transport materials based on the spiro [ fluorene-heterocycle ] structure;

the electron transport layer is composed of a compact titanium dioxide layer and a mesoporous titanium dioxide layer.

7. The perovskite solar cell of claim 6, wherein the transparent conductive substrate is FTO conductive glass;

the material component of the perovskite layer is APbB₃Wherein A is one or more of Cs, FA and MA, and B is one or two of I and Br;

the metal electrode is gold (Au);

the thickness of the compact titanium dioxide layer is 0.01-30 nm; the thickness of the mesoporous titanium dioxide layer is 60-280 nm; the thickness of the perovskite layer is 200-550 nm; the thickness of the hole transport layer is 40-170 nm; the thickness of the metal electrode is 60-100 nm.

8. The perovskite solar cell according to claim 6, characterized in that the material of the perovskite layer is Cs_0.05FA_0.85MA_0.10Pb(I_0.97Br_0.03)₃。

9. The method for producing a perovskite solar cell as claimed in claim 6, characterized by comprising the steps of:

s1: carrying out ultrasonic cleaning and drying on the transparent conductive substrate, and then carrying out ozone ultraviolet treatment;

s2: preparing compact TiO on the treated transparent conductive substrate by a spray pyrolysis method₂A layer;

s3: adding TiO into the mixture₂Dense TiO spin-coated to S2 after slurry dilution₂Sintering on the film to obtain mesoporous TiO₂A layer;

s4: preparing perovskite precursor liquid, and spin-coating the perovskite precursor liquid to mesoporous TiO 3₂Annealing the film to form a perovskite layer;

s5: preparing a hole transport material containing a spiro [ fluorene-heterocycle ] structure into a solution, and spin-coating the solution on the surface of the perovskite thin film of S4 to obtain a hole transport layer;

s6: and depositing a metal electrode on the hole transport layer by a vacuum evaporation method.

10. The method for preparing the perovskite solar cell as claimed in claim 9, wherein the cleaning treatment in step S1 is ultrasonic cleaning with a cleaning agent, deionized water, acetone and ethanol for 10-30 min, and ozone ultraviolet treatment for 10-30 min;

preferably, in step S2, the spraying solution is ethanol, titanium acetylacetonate and acetylacetone in a ratio of 40-45: 2-5: 2 (volume ratio), and pyrolyzing for 10-30 min at 400-500 ℃ under the pyrolysis condition;

preferably, in step S3, TiO₂The slurry was mixed with ethanol according to 1: diluting at a ratio of 5-7 (mass ratio), wherein the spin-coating rotation speed is 3000-5000 rpm, and sintering treatment conditions are sintering at 400-500 ℃ for 20-45 min;

preferably, in step S4, the solvent for preparing the perovskite precursor solution is a DMF/DMSO mixed solvent with a volume ratio of 3-5: 1, and the heating and dissolving temperature is 60-80 ℃; spin-coating perovskite precursor liquid in two spin-coating processes, wherein the first process is spin-coating at 1500-3000 rpm for 6-15 s, and the second process is spin-coating at 4000-7000 rpm for 15-25 s; dripping 80-120 mu L of chlorobenzene 3-8 s before the second process is finished; annealing conditions are 100-130 ℃ for 10-30 min;

preferably, in step S5, the concentration of the hole transport material containing spiro [ fluorene-heterocycle ] structure is 10 to 80mmol/mL, the solvent is chlorobenzene, and 15 to 25 μ L of 4-tert-butylpyridine and 7 to 15 μ L of lithium bis (trifluoromethanesulfonyl) imide (acetonitrile solution with concentration of 500 to 550 mg/mL) are added to each mL of chlorobenzene solution; the spin coating condition is 3000-5000 rpm for 10-30 s.

Technical Field

The invention relates to the technical field of organic photoelectric materials, in particular to a preparation method of a hole transport material containing a spiro [ fluorene-heterocycle ] structure and application of the hole transport material in a perovskite solar cell.

Background

In recent years, organic-inorganic hybrid Perovskite Solar Cells (PSCs) have become a research hotspot of a new generation of solar cells due to the advantages of wide material sources, simple preparation process, high Photoelectric Conversion Efficiency (PCE), and the like. In 2009, the japanese scientist Miyasaka et al applied perovskite light absorbing materials to solar cells for the first time and achieved 3.8% photoelectric conversion efficiency (Kojima a, Teshima K, Shirai Y, Miyasaka t.journal of the American Chemical Society,2009,131(17): 6050-. With the continuous and deep research of researchers on PSCs, the certified photoelectric conversion efficiency of the perovskite solar cell breaks through 25% at present, and the perovskite solar cell shows good application and development prospects.

As an important component of perovskite solar cells, Hole Transport Materials (HTMs) play an essential role in accelerating hole extraction and transport, inhibiting carrier recombination, protecting perovskite layers from erosion, and the like, and the performance of the HTMs directly affects the photovoltaic performance of PSCs. Currently, the most used hole transport material in perovskite solar cells is 2,2',7,7' -tetrakis [ N, N-bis (4-methoxyphenyl) amino ] -9,9' -spirobifluorene (spiro-OMeTAD). However, the synthesis steps of the spiro-OMeTAD are complex and the purification is complicated, so that the cost is high, and the commercial development of the perovskite solar cell is not facilitated. Therefore, the development and preparation of a hole transport material with simplicity and excellent performance is one of the important research points in the field of perovskite solar cells, and has important significance for promoting the commercialization process of perovskite solar cells.

Disclosure of Invention

The invention aims to provide a hole transport material containing a spiro [ fluorene-heterocycle ] structure, a preparation method thereof and application thereof in perovskite solar cells, aiming at the defects in the prior art. The material takes spiro [ fluorene-9, 4 '-imidazoline ] -2', 5 '-diketone or spiro [ fluorene-9, 4' -imidazoline ] -2 ', 5' -dithione with alkyl connected on nitrogen as a central core, diphenylamine, carbazole, phenothiazine or phenoxazine containing methoxyl or methylthio substitution as an end group, and hetero atoms in the central spiro [ fluorene-heterocycle ] core can passivate the surface defect of a perovskite layer; in the preparation, under the action of trifluoroacetic acid or a sulfonic acid compound, the 9, 10-phenanthrenequinone compound and urea or a urea derivative react to synthesize a spiro [ fluorene-9, 4' -imidazoline ] -2 ', 5 ' -dione compound, the reaction condition is mild, the preparation is simple and convenient, and a novel method is provided for synthesizing the spiro skeleton structure compound.

In order to achieve the purpose, the invention provides the following technical scheme:

a hole transport material containing a spiro [ fluorene-heterocycle ] structure is disclosed, wherein the chemical structure general formula of the compound is shown as formula I:

wherein X is an oxygen atom or a sulfur atom; r is C1-C12 alkyl; g is any one of the following structural formulas:

preferably, R is C1-C6 hydrocarbyl.

More preferably, G isR is methyl to obtain the hole transport material with the chemical structure shown as SFHc- (1) or SFHc- (2):

the preparation method of the hole transport material containing the spiro [ fluorene-heterocycle ] structure.

The synthesis steps of the SFHc- (1) are as follows:

s1: under the protection of inert gas, adding 2, 7-dibromo-9, 10-phenanthrenequinone, 1, 3-dimethylurea, acid and a first solvent into a reactor with a water separator, and reacting at 100-120 ℃ for 10-12 h to obtain a spiro compound 1;

wherein the mol ratio of the 2, 7-dibromo-9, 10-phenanthrenequinone to the 1, 3-dimethylurea to the acid is 1: 1-3: 1-5, wherein the dosage of the solvent is 2-20 mL of the solvent added in each millimole of 2, 7-dibromo-9, 10-phenanthrenequinone;

the acid is one or more of trifluoroacetic acid or sulfonic acid compounds; the sulfonic acid compound is p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid or camphorsulfonic acid.

S2: under the protection of inert gas, adding a compound 1, 4' -dimethoxydiphenylamine, a strong base, a catalyst and a second solvent into a reactor, and reacting for 10-15 h at 105-115 ℃ to obtain a hole transport material SFHc- (1);

wherein the mol ratio of the compound 1 to the 4,4' -dimethoxydiphenylamine is 1: 2.5-3.5, wherein the molar ratio of the strong base to the catalyst to the compound 1 is 2-6: 0.03 to 2: 1; 2-20 mL of the second solvent is added per millimole of the compound 1.

The reaction is that the strong base is sodium tert-butoxide or potassium tert-butoxide, the catalyst is tris (dibenzylideneacetone) dipalladium and a substance M, the substance M is tri-tert-butylphosphine or tri-tert-butylphosphine tetrafluoroborate, and the molar ratio of tris (dibenzylideneacetone) dipalladium to the substance M is 0.01-1: 0.02 to 1.

The synthesis steps of the SFHc- (2) are as follows:

and under the protection of inert gas, reacting the third solvent, the compound SFHc- (1) and the Lawson reagent at 105-115 ℃ for 9-11 h to obtain the hole transport material SFHc- (2).

Preferably, the molar ratio of SFHc- (1) to lawson's reagent is 1: 2-4, adding 2-20 mL of a third solvent per millimole of the compound SFHc- (1).

The first solvent, the second solvent and the third solvent are all toluene.

Preferably, the inert gas in the above reaction step is argon or nitrogen.

The invention also provides a perovskite solar cell which sequentially comprises a transparent conductive substrate, an electron transport layer, a perovskite layer, a hole transport layer and a metal electrode from bottom to top, wherein the hole transport layer is made of any one of the hole transport materials based on the spiro [ fluorene-heterocycle ] structure.

Preferably, the transparent conductive substrate is FTO conductive glass.

Preferably, the electron transport layer is composed of a dense titania layer and a mesoporous titania layer.

Preferably, the material component of the perovskite layer is APbB₃Wherein A is one or more of Cs, FA and MA, and B is one or two of I and Br;

more preferably Cs_0.05FA_0.85MA_0.10Pb(I_0.97Br_0.03)₃。

Preferably, the metal electrode is gold (Au).

Preferably, the thickness of the compact titanium dioxide layer is 0.01-30 nm; the thickness of the mesoporous titanium dioxide layer is 60-280 nm; the thickness of the perovskite layer is 200-550 nm; the thickness of the hole transport layer is 40-170 nm; the thickness of the metal electrode is 60-100 nm.

The preparation method of the perovskite solar cell comprises the following steps:

s1: carrying out ultrasonic cleaning and drying on the transparent conductive substrate, and then carrying out ozone ultraviolet treatment;

s2: preparing compact TiO on the treated transparent conductive substrate by a spray pyrolysis method₂And (3) a layer.

S3: adding TiO into the mixture₂Dense TiO spin-coated to S2 after slurry dilution₂Sintering on the film to obtain mesoporous TiO₂A layer;

s4: preparing perovskite precursor liquid, and spin-coating the perovskite precursor liquid to mesoporous TiO 3₂Annealing the film to form a perovskite layer;

s5: preparing a hole transport material containing a spiro [ fluorene-heterocycle ] structure into a solution, and spin-coating the solution on the surface of the perovskite thin film of S4 to obtain a hole transport layer;

s6: and depositing a metal electrode on the hole transport layer by a vacuum evaporation method.

Preferably, the cleaning treatment in step S1 is ultrasonic cleaning with a cleaning agent, deionized water, acetone and ethanol for 10-30 min, and ozone ultraviolet treatment for 10-30 min.

Preferably, in step S2, the spraying solution is ethanol, titanium acetylacetonate and acetylacetone in a ratio of 40-45: 2-5: 2 (volume ratio) and carrying out pyrolysis for 10-30 min at 400-500 ℃.

Preferably, in step S3, TiO₂The slurry was mixed with ethanol according to 1: 5-7 (mass ratio), the spin-coating speed is 3000-5000 rpm, and the sintering treatment condition is sintering at 400-500 ℃ for 20-45 min.

Preferably, in step S4, the solvent for preparing the perovskite precursor solution is a DMF/DMSO mixed solvent with a volume ratio of 3-5: 1, and the heating and dissolving temperature is 60-80 ℃; spin-coating perovskite precursor liquid in two spin-coating processes, wherein the first process is spin-coating at 1500-3000 rpm for 6-15 s, and the second process is spin-coating at 4000-7000 rpm for 15-25 s; dripping 80-120 mu L of chlorobenzene 3-8 s before the second process is finished; the annealing condition is 100-130 ℃ annealing for 10-30 min.

Preferably, in step S5, the concentration of the hole transport material containing spiro [ fluorene-heterocycle ] structure is 10 to 80mmol/mL, the solvent is chlorobenzene, and 15 to 25 μ L of 4-tert-butylpyridine and 7 to 15 μ L of lithium bis (trifluoromethanesulfonyl) imide (acetonitrile solution with concentration of 500 to 550 mg/mL) are added to each mL of chlorobenzene solution; the spin coating condition is 3000-5000 rpm for 10-30 s.

Compared with the prior art, the invention has the following beneficial effects:

1. the hole transport material containing the spiro [ fluorene-heterocycle ] structure provided by the invention has the advantages of simple synthetic route, easily obtained raw materials and easy purification; meanwhile, the hole transport material containing the spiro [ fluorene-heterocycle ] structure has good solubility, film forming property and thermal stability.

2. The hole transport material containing the spiro [ fluorene-heterocycle ] structure is applied to perovskite solar cells, and test results show that the cell device can obtain good photoelectric conversion efficiency (the highest photoelectric conversion efficiency can exceed 21%) and has wide application prospects.

Drawings

FIG. 1 shows UV-VIS absorption spectra (10) of the hole transport materials SFHc- (1) and SFHc- (2) according to the present invention^{- 5}mol/L, dichloromethane solution);

FIG. 2 is a TGA curve of a hole transport material SFHc- (1) according to the present invention;

FIG. 3 is a TGA curve of a hole transport material SFHc- (2) according to the present invention;

FIG. 4 is a DSC curve of the hole transport material SFHc- (1) of the present invention;

FIG. 5 is a DSC curve of the hole transport material SFHc- (2) of the present invention;

FIG. 6 is a schematic view of the device structure of the perovskite solar cell of the present invention;

FIG. 7 is a J-V curve of a perovskite solar cell device based on SFHc- (1) and SFHc- (2) of the invention.

Detailed Description

The present invention is further illustrated by the following specific examples to enable those skilled in the art to better understand the present invention, but the present invention is not limited to the following examples.

The experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.

Example 1: synthesis of spiro [ fluorene-heterocycle ] hole transport materials SFHc- (1) and SFHc- (2).

The synthetic routes of SFHc- (1) and SFHc- (2) are as follows:

synthesis of intermediate 1: 2, 7-dibromo-9, 10-phenanthrenequinone (1.76g,4.8mmol), 1, 3-dimethylurea (0.86g,9.8mmol), and toluene (20mL) were sequentially added to a 50mL round-bottomed flask, and after stirring at room temperature for 2min, trifluoroacetic acid (2.23g, 19.6mmol) was added, a water separator and a reflux condenser were attached, and the reaction was refluxed (110.6 ℃ C.) under an argon atmosphere for 12 hours. After the reaction is finished, the temperature is reduced to room temperature, the solvent is removed under reduced pressure, and a column layer is formedThe product was isolated by chromatography (petroleum ether: dichloromethane: 1: 2) to give 1.07g of a white solid in 51% yield.¹H NMR(400MHz,CDCl₃)δ(ppm):7.62-7.57(m,4H),7.41(s,2H),3.21(s,3H),2.60(s,3H).¹³C NMR(100MHz,CDCl₃)δ(ppm):170.6,156.6,141.3,139.7,133.8,126.9,122.5,122.4,74.6,26.0,25.9.

Synthesis of Compound SFHc- (1): a50 mL round bottom flask was charged with intermediate 1(1.31g,3mmol), 4' -dimethoxydiphenylamine (2.06g,9mmol), tris (dibenzylideneacetone) dipalladium (0.28g,0.3mmol), sodium tert-butoxide (1.49g,15.5mmol), tri-tert-butylphosphine tetrafluoroborate (0.21g,0.72mmol), and toluene (20mL) in that order, and refluxed (110.6 ℃ C.) under argon atmosphere for 12 h. Cooling to room temperature, removing the solvent in vacuo, separating by column chromatography (petroleum ether: ethyl acetate: 2: 1), and further recrystallizing with ethyl acetate and n-hexane to purify the product to obtain a pale yellow solid 1.14g, with a yield of 52%.¹H NMR(400MHz,Acetone-d₆)δ(ppm):7.55(d,J＝8.4Hz,2H),7.02(d,J＝7.2Hz,8H),6.89(d,J＝8.4Hz,12H),3.78(s,12H),2.88(s,3H),2.51(s,3H).¹³C NMR(100MHz,Acetone-d₆)δ(ppm):169.8,154.7,146.8,140.0,139.2,132.9,124.9,120.7,118.9,114.0,113.2,73.3,53.3,23.3,23.1.HRMS(ESI):calcd for C₄₅H₄₀N₄O₆[M⁺]732.2942,found 732.2952.

Synthesis of Compound SFHc- (2): a 50mL round bottom flask was charged with the compound SFHc- (1) (0.97g,1.32mmol), lawson's reagent (CAS No.: 19172-47-5, 1.07g,2.65mmol), and toluene (20mL), refluxed for 10 hours under an argon atmosphere, then cooled to room temperature, the solvent was removed in vacuo, and separated by column chromatography (petroleum ether: dichloromethane ═ 1: 1) and further recrystallized from dichloromethane and n-hexane for purification to give 0.49g of a yellow solid in 49% yield.¹H NMR(400MHz,CDCl₃)δ(ppm):7.34(d,J＝8.4Hz,2H),6.99(d,J＝8.4Hz,8H),6.91(d,J＝8.0Hz,2H),6.80(d,J＝8.4Hz,8H),6.67(s,2H),3.79(s,12H),3.62(s,3H),2.91(s,3H).¹³C NMR(100MHz,CDCl₃)δ(ppm):202.3,181.3,155.8,148.4,143.3,140.6,134.0,126.1,123.0,120.3,115.9,114.7,86.4,55.4,33.7,31.7.HRMS(ESI):calcd for C₄₅H₄₀N₄O₄S₂[M⁺]764.2485,found 764.2491.

The thermal decomposition temperatures of the compounds SFHc- (1) and SFHc- (2) prepared in example 1 were measured, and the results are shown in FIGS. 2 and 3, indicating that both compounds have good thermal stability, based on 5% weight loss.

The glass transition temperatures of the compounds SFHc- (1) and SFHc- (2) prepared in example 1 were measured, and the results (see FIGS. 4 and 5) were 120 ℃ and 111 ℃, respectively.

Example 2: the compound SFHc- (1) is used as a hole transport material and is applied to perovskite solar cell devices, and the preparation method comprises the following steps:

(1) ultrasonically cleaning fluorine-doped tin oxide glass with an etching groove with a cleaning agent, deionized water, acetone and ethanol for 20min respectively in sequence, and using N₂Blow-drying and then carrying out O for 20min₃UV treatment.

(2) Measuring ethanol, titanium acetylacetonate and acetylacetone according to a ratio of 45: 3: 2 (volume ratio), spraying nitrogen as carrier gas onto FTO substrate at 450 deg.C, heating for 20min, and naturally cooling to obtain compact TiO₂And (3) a layer.

(3) Adding TiO into the mixture₂Slurry and ethanol were mixed according to a 1: 6 (mass ratio), then ultrasonically treating and stirring to uniformly disperse the TiO, and spin-coating the TiO on dense TiO at 4000rpm₂On the layer, sintering at 450 deg.C for 30min to form mesoporous TiO₂A layer; the thickness was 220 nm.

(4) Weighing PbI₂(1.58mmol), FAI (1.28mmol), MABr (0.15mmol), CsI (0.08mmol) in 1mL volume 4: 1, heating to 70 ℃ to dissolve to obtain a precursor solution. Taking a precursor solution (60 mu L) to spin-coat on TiO through two spin-coating processes₂Spin-coating at 2000rpm for 10s in the first process, then spin-coating at 6000rpm for 20s in the second process, dripping 100 mu L of chlorobenzene 5s before the second process is finished, and immediately annealing on a 120 ℃ hot bench for 20min after the spin-coating is finished to form a perovskite thin film; the thickness was 450 nm.

(5) Weighing SFHc- (1) and dissolving in chlorobenzene to prepare a 40mmol/mL solution, then adding 4-tert-butylpyridine (23.667 mu L) and acetonitrile solution (520mg/mL) of lithium bis (trifluoromethanesulfonimide) (10.673 mu L) into each milliliter of solution, and then spin-coating on the surface of the perovskite film for 20s at the speed of 4000 rpm; the thickness was 70 nm.

(6) Vacuum evaporating a layer of 80nm gold electrode on the surface of the film obtained in the step (5) to obtain the perovskite solar cell, wherein the effective area of the perovskite solar cell is 0.16cm²。

Example 3: the compound SFHc- (2) is used as a hole transport material and is applied to perovskite solar cell devices.

The other steps are the same as those in example 2 except that SFHc- (1) is replaced with SFHc- (2) in the step (5).

And (3) photovoltaic performance testing:

xenon lamp solar simulator, AM 1.5G intensity (100 mW/cm) in a glove box under nitrogen atmosphere²) The perovskite solar cell devices prepared as described above were tested for current density-voltage (J-V) curves.

The J-V curve after the test is shown in FIG. 7. The short-circuit current density (Jsc) of the perovskite solar cell device corresponding to the compound SFHc- (2) is 24.18mA/cm²Open circuit voltage (Voc) is 1.100V, Fill Factor (FF) is 0.809, and energy conversion efficiency (PCE) is 21.52%; as can be seen from fig. 7, this result is superior to the photovoltaic performance of the SFHc- (1) -based perovskite solar cell device under the same conditions (Jsc-24.01 mA/cm)²，Voc＝0.975V，FF＝0.721，PCE＝16.87％)。

The foregoing is merely a preferred embodiment of the present invention, which is provided for the purpose of illustration and not for the purpose of limitation, and it will be understood by those skilled in the art that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention, and these changes, substitutions and alterations should not be limited by the scope of the invention.

The invention is not the best known technology.