Hole transport material, hole transport layer and solar cell thereof

Abstract

The invention provides a hole transport material, a hole transport layer and a solar cell thereof. The hole transport material comprises an SAM material and nucleotide; wherein the SAM material is an SAM material containing a phosphate group. The hole transport layer is prepared from the hole transport material, so that the wettability of SAM and a perovskite substrate is improved, and the preparation of a large-area perovskite module is facilitated; hygroscopicity is reduced, and photoelectric conversion efficiency and stability of the device are improved.

Description

Technical Field

[0001] The present invention relates to the field of perovskite solar cells, and in particular to a hole transport material, a hole transport layer and a solar cell thereof. Background Art

[0002] Thanks to the development of perovskite film-forming technology and its own material technology, the photoelectric conversion efficiency of perovskite solar cell technology has increased from 3.8% to more than 26% in the past decade. At present, the development of efficient, stable and low-cost charge transport materials, especially hole transport materials (HTM), is crucial to promote the commercialization of PSC (perovskite solar cells).

[0003] Currently, the development of efficient, stable and low-cost charge transport materials, especially hole transport materials (HTMs), is crucial to promote PSCs towards commercialization. Recently, an anchoring-based self-assembly strategy has been demonstrated to be able to construct efficient hole transport layers for high-performance pin-structured PSCs. The process uses molecular HTMs that include anchoring groups (e.g., carboxyl groups) that can spontaneously adsorb onto the surface of oxide substrates to form a monolayer coverage. Compared with traditional thick hole transport layers (HTLs) based on spin coating or spray pyrolysis, the self-assembled monolayer has the advantages of minimal material consumption and low parasitic absorption. In addition, the chemical bath deposition-based method is a low-cost and scalable process route that has been successfully applied to small modules as well as large-area perovskite silicon tandem solar cells.

[0004] However, the self-assembled molecular layers reported so far still have problems with insufficient stability and poor wettability, and poor uniformity in large-area preparation, which leads to leakage current. This leaves a big obstacle for the application of more effective HTM. Summary of the invention

[0005] In view of the technical problems that the hole transport layer prepared by the self-assembled molecular layer used in the above-mentioned prior art has insufficient stability and poor wettability, the present invention provides a hole transport material, a hole transport layer and a solar cell thereof. The hole transport layer is prepared by using the hole transport material of the present invention, which increases the wettability on the SAM (self-assembled monolayer) and the perovskite substrate, is conducive to the preparation of large-area perovskite modules; reduces hygroscopicity, and improves the photoelectric efficiency and stability of the device.

[0006] Specifically, the first aspect of the present invention provides a hole transport material, which includes a SAM material and a nucleotide, wherein the SAM material is a SAM material containing a phosphate group.

[0007] In one or more embodiments, the mass ratio of SAM material to nucleotide is (10-5):1.

[0008] In one or more embodiments, the nucleotide is one or more of adenylic acid, guanylic acid, cytidylic acid, uridylic acid, thymidylic acid, xanthylic acid, and inosinic acid.

[0009] In one or more embodiments, the SAM material is a compound of formula A:

[0010]

[0011] In formula A, X is selected from a bond or C(R 3 )(R 3a );R 1 and R 2 Each is independently selected from hydrogen, C1-4 alkyl, C1-4 alkoxy or halogen; Y is selected from C1-6 alkyl or phenyl.

[0012] In one or more embodiments, the SAM material is selected from one or more of the compounds of formula I, formula II, formula III, formula IV, and formula V:

[0013]

[0014]

[0015] A second aspect of the present invention provides a composite hole transport layer, wherein the composite hole transport layer comprises a hole transport material as described in any embodiment of the present invention.

[0016] The third aspect of the present invention provides a method for preparing a composite hole transport layer as described in any embodiment of the present invention, the method comprising: dispersing a SAM material and a nucleotide in a solvent, filtering to obtain a hole transport material dispersion; coating the dispersion on a substrate, annealing to obtain a composite hole transport layer.

[0017] In one or more embodiments, the total mass concentration of the SAM material and the nucleotide in the dispersion is 0.1-1 mg / mL or 0.5-0.7 mg / mL.

[0018] In one or more embodiments, the solvent is selected from one or more of isopropanol, ethanol, chloroform, and N,N-dimethylformamide.

[0019] In one or more embodiments, the filtration is performed at a fineness of 210-230 nm.

[0020] In one or more embodiments, the coating is performed by spin coating.

[0021] In one or more embodiments, the annealing temperature is 80-120° C., such as 100° C., and the annealing time is 8-12 min.

[0022] A fourth aspect of the present invention provides a perovskite solar cell, which comprises a stacked conductive glass layer or a conductive glass layer + an inorganic hole transport layer, a composite hole transport layer as described in any embodiment of the present invention, a perovskite light absorbing layer, an electron transport layer and an electrode, and optionally a hole blocking layer arranged between the electron transport layer and the electrode.

[0023] In one or more embodiments, the perovskite solar cell is a pin-type perovskite solar cell.

[0024] A fifth aspect of the present invention provides the use of nucleotides in enhancing the stability of a hole transport layer prepared using a self-assembled molecular layer, and / or increasing its wettability with a perovskite substrate;

[0025] The sixth aspect of the present invention provides the use of nucleotides in reducing the hygroscopicity of a hole transport layer prepared by a self-assembled molecular layer and improving the photoelectric efficiency and stability of the device;

[0026] A seventh aspect of the present invention provides the use of a hole transport material as described in any embodiment of the present invention in the preparation of a perovskite solar cell.

[0027] An eighth aspect of the present invention provides the use of a hole transport material as described in any embodiment herein for enhancing the wettability of a SAM with a perovskite substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of a perovskite solar cell according to one embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in this article. Unless otherwise specified, all technical and scientific terms used in this article are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definitions in this article shall prevail.

[0030] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0031] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0032] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0033] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0034] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0035] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0036] In this article, self-assembled monolayers are referred to as SAM.

[0037] The purpose of the present invention is to provide a hole transport material, a hole transport layer and a cell for a perovskite solar cell. The hole transport material of the present invention is used to prepare the hole transport layer, which increases the mutual wettability of the SAM and the perovskite substrate, facilitates the preparation of a large-area perovskite module, reduces hygroscopicity, and improves the photoelectric efficiency and stability of the device.

[0038] In some embodiments, such as Figure 1 As shown, the perovskite solar cell includes TCO conductive glass, a composite hole transport layer, a perovskite layer, an electron transport layer and an electrode from bottom to top.

[0039] The composite hole transport layer of the present invention comprises a SAM material and nucleotides, wherein the SAM material is a SAM material containing a phosphate group.

[0040] In some embodiments, the nucleotide is one or more of adenylic acid, guanylic acid, cytidylic acid, uridylic acid, thymidylic acid, xanthinyl acid, and inosinic acid.

[0041] In the SAM material of the present invention, the phosphate group is used as the anchoring group of the SAM material. The inventors found that by adding nucleotides to the SAM whose anchoring group is the phosphate group; utilizing the anchoring effect of the phosphate group in the nucleotide and the substrate, and having a nucleic acid head that interacts with the perovskite, the wettability of the perovskite on the substrate is enhanced, which is beneficial to the preparation of a large-area perovskite module; reducing hygroscopicity and improving the efficiency and stability of the device.

[0042] In some embodiments, the SAM material is a compound of formula A:

[0043]

[0044] In formula A, X is selected from a bond or C(R 3 )(R 3a );R 1 and R 2 Each is independently selected from hydrogen, C1-4 alkyl, C1-4 alkoxy or halogen; Y is selected from C1-6 alkyl or phenyl.

[0045] In some embodiments, the halogen can be one or more of F, Cl, Br, and I.

[0046] In some embodiments, the SAM material is selected from one or more of the compounds of formula I, formula II, formula III, formula IV, and formula V:

[0047]

[0048] In some embodiments, the SAM material is selected from a compound of Formula I, a compound of Formula II, a compound of Formula III, a compound of Formula IV, or a compound of Formula V.

[0049] In some embodiments, the mass ratio of SAM material to nucleotide is (10-5):1.

[0050] The composite hole transport layer of the present invention can be prepared by a solution process.

[0051] In some embodiments, the present invention provides a method for preparing a composite hole transport layer, which comprises dispersing a SAM material and a nucleotide in a solvent, filtering to obtain a hole transport material dispersion; coating the dispersion on a substrate, and annealing to obtain a composite hole transport layer.

[0052] In some embodiments, the dispersion method may be ultrasonic dispersion, and the dispersion time may be 15-25 minutes.

[0053] After dispersion, the modified hole transport material dispersion can be formed by filtering using a 210-230 nm, such as a 220 nm, PTFE filter.

[0054] In some embodiments, the total mass of the SAM material and the nucleotides and the volume ratio of the solvent is (0.1-1) mg / mL or (0.5-0.7) mg / mL. Generally, the total mass of the SAM material and the nucleotides and the volume ratio of the solvent are satisfied. In some preferred embodiments, the mass volume ratio of the SAM material and the solvent is (0.05-0.95) mg / mL or (0.05-0.5) mg / mL. In some preferred embodiments, the mass volume ratio of the nucleotides and the solvent is (0.05-0.95) mg / mL or (0.05-0.1) mg / mL.

[0055] In some embodiments, the above dispersion can be dropped onto a substrate such as TCO glass and coated by spin coating. The spin coating speed can be 4500-5500 rpm and the spin coating time can be 25-35 s.

[0056] After spin coating, annealing treatment is performed. In some embodiments, the TCO glass spin-coated with the hole transport material dispersion can be placed on a hot plate for heating annealing treatment. The heating temperature can be 80-120° C., such as 100° C., and the heating time can be 8-12 minutes to obtain a composite hole transport layer.

[0057] In some embodiments, the composite hole transport layer has a thickness of 0.5-5 nm.

[0058] The present invention also includes a perovskite solar cell, which includes a conductive glass layer or a conductive glass layer + an inorganic hole layer, a composite hole transport layer as described herein, a perovskite light absorbing layer, an electron transport layer and an electrode, and a hole blocking layer optionally disposed between the electron transport layer and the electrode, arranged in sequence from bottom to top.

[0059] The conductive glass layer applicable to the present invention may be a conventional conductive glass used in the art for preparing perovskite solar cells, such as TCO conductive glass.

[0060] The material suitable for the inorganic hole transport layer of the present invention can be selected from one or more of nickel oxide, cuprous iodide, cuprous thiocyanate, cupric oxide, cuprous oxide, copper sulfide and antimony-doped tin oxide nanoparticles. The preparation of the inorganic hole transport layer is not particularly limited, and the conventional method for preparing the hole transport layer in the art can be used, such as a magnetron sputtering process. The process parameters can be adjusted according to the target thickness of the inorganic hole transport layer. In some embodiments, the thickness of the inorganic hole transport layer is 1nm-100nm.

[0061] The active material of the perovskite active layer suitable for the present invention comprises a first perovskite material and a second perovskite material; wherein the first perovskite material is selected from at least one of a lead halide salt and a tin halide salt, and the second perovskite material is selected from at least one of a formamidine halide salt, a methylamine halide salt and a cesium halide salt. In some embodiments, the materials of the perovskite absorption layer are lead iodide and iodomethylamine. The preparation of the perovskite active layer is not particularly limited, and the conventional method for preparing the perovskite active layer in the art can be used, including but not limited to one or more of spin coating, blade coating, evaporation, printing, spraying, spray pyrolysis, and slit coating. The process parameters can be adjusted according to the target thickness of the perovskite absorption layer. In some embodiments, the thickness of the perovskite absorption layer is 450nm-550nm.

[0062] Materials suitable for the electron transport layer of the present invention include, but are not limited to, one or more of [6,6]-phenyl-C61-butyric acid methyl ester, C60 and tin oxide. The preparation of the electron transport layer is not particularly limited, and the conventional method for preparing the electron transport layer in the art can be used, including but not limited to one or more of spin coating, spray coating, spray pyrolysis, slit coating, and atomic layer deposition. The process parameters can be adjusted according to the target thickness of the electron transport layer. In some embodiments, the thickness of the electron transport layer is 10nm-100nm, such as 20-40nm.

[0063] Materials suitable for the hole blocking layer of the present invention include, but are not limited to, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline and zirconium acetylacetonate. The preparation of the hole blocking layer is not particularly limited, and the conventional method for preparing the hole blocking layer in the art can be used, including but not limited to one or more of spin coating, spray coating, spray pyrolysis, slit coating, and atomic layer deposition. The process parameters can be adjusted according to the target thickness of the hole blocking layer. In some embodiments, the thickness of the hole blocking layer is 1nm-10nm, such as 5-8nm.

[0064] The material suitable for the electrode of the present invention can be selected from one or more of silver, copper, conductive oxide and carbon electrode. In some embodiments, the thickness of the electrode is 90nm-400nm, such as 80-120nm.

[0065] In some embodiments, the perovskite solar cell of the present invention is a single-junction perovskite solar cell or a tandem perovskite solar cell. Tandem perovskite solar cells exemplarily include two-terminal tandem cells, three-terminal tandem cells, and four-terminal tandem cells. In some embodiments, the perovskite solar cell is a pin-type perovskite solar cell.

[0066] Beneficial effects of the present invention:

[0067] The present invention adopts nucleotides and SAM materials to prepare the hole transport layer, which is beneficial to the uniformity of SAM on the substrate, increases the wettability of SAM on the perovskite substrate, and is beneficial to the preparation of large-area perovskite modules; reduces hygroscopicity and improves the efficiency and stability of the device; when preparing the perovskite layer, it is beneficial to the wettability of perovskite on SAM, promotes the coverage and film formation of perovskite, and is beneficial to the preparation of large-area batteries.

[0068] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples can all be purchased through commercial routes.

[0069] Example 1

[0070] (1) The TCO conductive glass was ultrasonically cleaned with deionized water, acetone and isopropanol for 15 minutes respectively, and finally dried in a drying oven at 75°C for standby use; the dried TCO glass substrate was placed in a UV ozone machine for 25 minutes to remove organic impurities on its surface and optimize its surface wettability;

[0071] (2) 0.5 mg of the SAM material of the compound of formula III and 0.1 mg of adenylic acid are dispersed in 1 mL of isopropanol solution; ultrasonication is performed for 20 min, and filtration is performed using a 220 nm PTFE filter to form a modified composite hole transport material dispersion;

[0072] (3) Take 30 μL of the above dispersion and drop it on the TCO glass. Spin-coat it at 5000 rpm for 30 seconds. Heat and anneal the TCO glass at 100 °C on a hot plate for 10 minutes to obtain a 1 nm composite hole transport layer.

[0073] (3) Dissolve 722.08 mg of lead iodide and 238.50 mg of iodomethylamine solid in 1 mL of N,N-dimethylformamide (DMF), stir at room temperature until completely dissolved, and obtain a perovskite precursor solution; in a nitrogen glove box, take 30 μL of the perovskite precursor solution and drop it onto the ITO conductive glass that forms the composite hole transport layer, first spin-coat it at 1000 rpm for 10 seconds, then spin-coat it at 5000 rpm for 30 seconds, and quickly drop 125 μL of chlorobenzene after 25 seconds of this process, and then place the TCO glass on a hot stage and heat and anneal it at 100°C for 40 minutes to form a perovskite light-absorbing layer of 500 nm;

[0074] (5) Dissolve 20 mg of methanefullerene phenyl-C61-butyric acid-methyl ester (PCBM) in 1 mL of chlorobenzene and stir at room temperature to obtain a [6,6]-phenyl-C61-butyric acid methyl ester solution; Take 30 μL of the [6,6]-phenyl-C61-butyric acid methyl ester solution and spin coat it on the ITO conductive glass with a perovskite light absorption layer at 3000 rpm for 60 seconds to form a 30 nm electron transport layer;

[0075] (6) Dissolve 0.5 mg of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in 1 mL of isopropanol and stir at room temperature to obtain a hole blocking layer solution; take 40 μL of the hole blocking layer solution and drop it onto the electron transport layer, and spin coat at 5000 rpm for 35 s to form a hole blocking layer of 6 nm;

[0076] (7) Transfer the TCO conductive glass forming the hole blocking layer, electron transport layer, perovskite light absorption layer, and hole transport layer to the vacuum coating instrument and wait until the vacuum degree is drawn to 3*10 -4 A silver electrode was evaporated at 400 ℃ and 100 nm thick on the hole blocking layer to obtain an electrode layer.

[0077] Example 2

[0078] The difference between Example 2 and Example 1 is that 0.1 mg of adenylic acid is replaced by 0.1 mg of guanylic acid.

[0079] Example 3

[0080] The difference between Example 3 and Example 1 is that 0.1 mg of adenylic acid is replaced by 0.1 mg of cytidylic acid.

[0081] Example 4

[0082] The difference between Example 4 and Example 1 is that 0.1 mg of adenylic acid is replaced by 0.1 mg of uridine acid.

[0083] Example 5

[0084] The difference between Example 5 and Example 1 is that 0.1 mg of adenylic acid is replaced by 0.1 mg of thymidylic acid.

[0085] Example 6

[0086] The difference between Example 6 and Example 1 is that 0.1 mg of adenylic acid is replaced by 0.1 mg of xanthic acid.

[0087] Example 7

[0088] The difference between Example 7 and Example 1 is that 0.1 mg of adenylic acid is replaced by 0.1 mg of inosinic acid.

[0089] Example 8

[0090] The difference between Example 8 and Example 1 is that 0.5 mg of the compound of formula III is replaced by 0.5 mg of the compound of formula I.

[0091] Example 9

[0092] The difference between Example 9 and Example 1 is that 0.5 mg of the compound of formula III is replaced by 0.5 mg of the compound of formula II.

[0093] Example 10

[0094] The difference between Example 10 and Example 1 is that 0.5 mg of the compound of formula III is replaced by 0.5 mg of the SAM material of the compound of formula IV.

[0095] Embodiment 11

[0096] The difference between Example 11 and Example 1 is that 0.5 mg of the compound of formula III is replaced by 0.5 mg of the compound of formula V.

[0097] Example 12

[0098] The difference between Example 12 and Example 1 is that the mass ratio of the compound of formula III to adenylic acid is 10:1, wherein the compound of formula III is 0.5 mg and the adenylic acid is 0.05 mg.

[0099] Embodiment 13

[0100] The difference between Example 13 and Example 1 is that before preparing the composite hole transport layer, an inorganic hole transport layer is prepared on the TCO glass, specifically: on the cleaned glass substrate with the TCO layer, a layer of nickel oxide is prepared by using a nickel oxide target with a diameter of 4 inches and a thickness of 4 mm by using radio frequency magnetron sputtering, the thickness of the nickel oxide is 15 nm, the deposition pressure is 2 Pa, and the argon gas flow rate is 85 sccm (standard state cubic centimeter per minute) to form an inorganic hole transport layer.

[0101] Comparative Example 1

[0102] The difference between Comparative Example 1 and Example 1 is that adenylic acid is not added in step (2), and the remaining operating steps and conditions are the same.

[0103] Comparative Example 2

[0104] The difference between Example 2 and Example 1 is that the mass ratio of the compound of formula III to adenylic acid is 2:1, wherein the compound of formula III is 0.5 mg and the adenylic acid is 0.25 mg.

[0105] Test Example 1

[0106] Photoelectric tests were performed on the perovskite solar cells prepared in Examples 1-14 and Comparative Examples 1-2. The test temperature was 25±1°C. The current density-voltage curves (JV curves) of the devices were obtained by using a source meter (Keithley 2400) under AM1.5G (100 mW / cm 2 ) obtained under illumination, the cell area is 0.08cm 2 , before the test, the light intensity was calibrated by a standard silicon cell, and the scanning rate was 10mV / s.

[0107] The open circuit voltage is the terminal voltage of the battery in the open circuit state. The short circuit current is the current density that the perovskite solar cell can generate under short circuit conditions. The fill factor is the ratio of the maximum power of the solar cell to the product of the open circuit voltage and the short circuit current. The photoelectric conversion efficiency can be calculated by measuring the current density-voltage curve (JV curves) of the solar cell.

[0108] The results are shown in Table 1 below.

[0109] Table 1. Photoelectric test results

[0110]

[0111]

[0112] It can be seen from Table 1 that, compared with Comparative Examples 1-2, Examples 1-13 of the present invention use the hole transport material of the present invention to prepare the composite hole transport layer, which can improve the photoelectric conversion efficiency and fill factor of the device.

[0113] Test Example 2

[0114] The perovskite solar cells prepared in Examples 1-5 and Comparative Examples 1-2 were tested for stability under air conditions (humidity between 30-60%). Specifically, the photoelectric conversion efficiency was tested after the device was placed in the air for 500 hours, and normalized; normalized efficiency = photoelectric conversion efficiency after aging / photoelectric conversion efficiency before aging × 100%, and the stability of the solar cell was tested by normalized efficiency. The photoelectric conversion efficiency after aging is the photoelectric conversion efficiency data measured after the device was placed in the air for 500 hours. The photoelectric conversion efficiency before aging is the photoelectric conversion efficiency of the battery measured in the above-mentioned test example 1. The specific test results are shown in Table 2.

[0115] Table 2: Battery stability test

[0116]

[0117] It can be seen from Table 2 that the present invention can improve the stability of the battery. This is because the additive can interact with the perovskite, effectively passivate various defects on the surface of the perovskite, inhibit carrier recombination at the interface, and improve the efficiency of the perovskite battery.

[0118] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A hole transport material, characterized in that: The hole transport material comprises a SAM material and nucleotides; wherein the SAM material is a SAM material containing a phosphonic acid group.

2. The hole transport material according to claim 1, characterized in that The nucleotides are one or more of adenylic acid, guanylic acid, cytidylic acid, uridylic acid, thymidylic acid, xanthineic acid and inosinic acid; and / or The mass ratio of SAM material to nucleotide is (10-5):

1.

3. The hole transport material according to claim 1, characterized in that The SAM material is a compound of formula A: In formula A, X is selected from a bond or C(R3)(R 3a ); R1 and R2 are each independently selected from hydrogen, C1-4 alkyl, C1-4 alkoxy or halogen; Y is selected from C1-6 alkyl or phenyl.

4. The hole transport material according to claim 3, characterized in that The SAM material is selected from one or more compounds of formula I, formula II, formula III, formula IV and formula V:

5. A composite hole transport layer, characterized in that: The composite hole transport layer comprises the hole transport material according to any one of claims 1 to 4.

6. A method for preparing a composite hole transport layer as claimed in claim 5, characterized in that: The method comprises: dispersing SAM material and nucleotide in a solvent, filtering to obtain a hole transport material dispersion; coating the hole transport material dispersion on a substrate, annealing to obtain a composite hole transport layer.

7. The method according to claim 5, characterized in that The method meets one or more of the following characteristics: The volume ratio of the total mass of the SAM material and the nucleotide to the solvent is (0.1-1) mg / mL or (0.5-0.7) mg / mL; In the hole transport material dispersion, the mass volume ratio of the SAM material to the solvent is (0.05-0.95) mg / mL or (0.05-0.5) mg / mL; In the hole transport material dispersion, the mass volume ratio of nucleotide to solvent is (0.05-0.95) mg / mL or (0.05-0.1) mg / mL; The solvent is selected from one or more of isopropanol, ethanol, chloroform and N,N-dimethylformamide; The filtration accuracy is 210-230nm; The coating method is spin coating; The annealing temperature is 80-120° C., such as 100° C., and the annealing time is 8-12 minutes.

8. A perovskite solar cell, characterized in that: The perovskite solar cell comprises a stacked conductive glass layer or a conductive glass layer + an inorganic hole transport layer, a composite hole transport layer as claimed in claim 4, a perovskite light absorbing layer, an electron transport layer and an electrode, and optionally a hole blocking layer arranged between the electron transport layer and the electrode.

9. The optoelectronic device according to claim 8, characterized in that The perovskite solar cell is a pin-type perovskite solar cell. 10.Select from the following applications: Application of nucleotides in enhancing the stability of a hole transport layer prepared by a self-assembled molecular layer and / or increasing its wettability with a perovskite substrate; The use of nucleotides in reducing the hygroscopicity of hole transport layers prepared using self-assembled molecular layers and improving the photoelectric efficiency and stability of devices; Use of the hole transport material according to claim 1 or 2 in the preparation of a perovskite solar cell; Use of the hole transport material as claimed in claim 1 or 2 in enhancing the wettability of a hole transport layer and a perovskite substrate.

Images