Perovskite solar cell based on perovskite thin film crystallization control and preparation method thereof

Abstract

The invention discloses a perovskite solar cell based on perovskite thin film crystallization control and a preparation method thereof, and the method comprises the steps: carrying out the spin coating and deposition of a hole transport layer on conductive glass, customizing and synthesizing small organic molecules with different functional groups through a Michael addition reaction, and taking the small organic molecules as a perovskite precursor additive to prepare a perovskite precursor solution; the perovskite thin film is prepared on the indium tin oxide transparent conductive glass deposited with the hole transport material through an anti-solvent method, and after annealing treatment, the thin film is flat and compact in surface, large in grain size and low in defect state density, and the crystal orientation is perpendicular to a substrate. Spin-coating the passivation layer precursor solution to form a passivation layer; performing vacuum thermal evaporation on the passivation layer to form an electron transport layer material; and sequentially carrying out thermal evaporation on a barrier layer material and a metal electrode on the electron transport layer material to obtain the perovskite solar cell. The prepared trans-perovskite solar cell has excellent photoelectric conversion efficiency and excellent device stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic materials and devices, and in particular relates to a method for synthesizing organic multifunctional molecules to control the crystallization dynamics of perovskite for use in efficient and stable solar cells and a preparation method thereof. Background Art

[0002] Perovskite solar cells, which have the characteristics of low cost, adjustable band gap, and high theoretical limit photoelectric conversion efficiency, are one of the current research frontiers. Due to the development of new hole transport materials and the use of regulatory strategies such as additive engineering and interface engineering, the photoelectric conversion efficiency of inverted structure perovskite solar cells has developed rapidly and reached a record certified value of 26.14%, showing its strong commercial investment and application potential. The preparation of high-quality perovskite films is the key to obtaining excellent photoelectric performance and stable devices, but in the preparation process of perovskite films, surface and grain boundary defects that dominate non-radiative recombination are easily formed. Therefore, regulating the growth and crystallization process of perovskite films and then reducing perovskite surface or grain boundary defects is an effective strategy to improve the performance of perovskite solar cells.

[0003] At present, various types of materials (inorganic salts, organic halide salts, organic small molecules, polymers) have been used as precursor additives to regulate the crystallization and growth process of perovskite films, inhibit the formation of defects in perovskite films, or reduce defect density. At present, organic halide salts and inorganic salts are widely studied for their effective passivation effect. It is reported that long-chain alkyl ammonium halides easily convert the top three-dimensional perovskite into a two-dimensional perovskite layer to hinder the interfacial carrier transport. Halogen anions with small ionic radius can easily bind to the perovskite lattice, resulting in the distortion of the octahedron. Therefore, there are certain risks in using organic halide salts and inorganic salts as precursor additives. Organic small molecules have more flexible structures and designable functional groups, which can avoid the above effects and may be more effective in the passivation of perovskite film defects. Theory and practice show that specific functional groups such as hydroxyl, carboxyl, and amino groups regulate the growth and crystallization of perovskite films and passivate surface defects to varying degrees. Therefore, the development of new organic small molecule precursor additives with multiple functional groups and optimal spatial structures is crucial to obtain high-quality perovskite films and high-performance perovskite solar cell devices.

[0004] Additive engineering plays a key role in achieving high-quality light-absorbing layers for high-performance and stable perovskite solar cells. Various functional groups in additives play different regulatory roles on the perovskite layer. However, few additive molecules can synergistically achieve the dual functions of regulating crystallization and passivating defects. Summary of the invention

[0005] In order to solve the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide a perovskite solar cell and a preparation method for controlling the crystallization of a perovskite film. The method uses the Michael addition reaction to customize the synthesis of 2-ureido-4-pyrimidone (UPy) organic small molecules with different functional groups as perovskite precursor additives to prepare a perovskite precursor solution, thereby obtaining a perovskite film with a smooth and dense surface, a large grain size, a low defect state density, and a crystal orientation perpendicular to the substrate, thereby preparing a high photoelectric conversion efficiency and stable inverse perovskite solar cell.

[0006] The present invention is achieved through the following technical solutions.

[0007] One aspect of the present invention provides a method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite film, comprising the following steps:

[0008] (1) Cleaning the indium tin oxide transparent conductive glass substrate and treating it with ultraviolet ozone;

[0009] (2) dissolving the hole transport layer material in an ethanol solution to prepare a hole transport layer precursor solution;

[0010] (3) dissolving cesium iodide, methylamine hydroiodide, formamidine hydroiodide, lead iodide and methylamine lead trichloride single crystal in a molar ratio of (0.03-0.05):(0.03-0.05):(0.70-0.90):(0.95-1.05):(0.04-0.06) in an organic solvent to obtain a mixed solution, and adding additives at a mass ratio of 1-5 mg per 1 mL of the mixed solution to prepare a perovskite precursor solution;

[0011] (4) dissolving the passivation layer material in an isopropanol solution to prepare a passivation layer precursor solution;

[0012] (5) spin coating a hole transport layer precursor solution on the cleaned and treated transparent conductive glass, and annealing to obtain a hole transport layer;

[0013] (6) Spin coating a perovskite precursor solution on a transparent conductive glass having a hole transport layer by an anti-solvent method, and obtaining a perovskite film after annealing;

[0014] (7) spin coating a passivation layer precursor solution on the transparent conductive glass deposited with the perovskite film to form a passivation layer;

[0015] (8) vacuum thermal evaporation of electron transport layer materials on the passivation layer;

[0016] (9) Thermally evaporate a barrier layer material and a metal electrode in sequence on the electron transport layer material to obtain a perovskite solar cell.

[0017] Preferably, the hole transport layer material is one of (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphonic acid, ethyl 2-[(2-chlorophenyl)(phenyl)amino]benzoate or (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid.

[0018] Preferably, the additive is prepared according to the following method:

[0019] Guanidine carbonate and 2-acetylbutyrolactone are mixed with anhydrous ethanol in a mass ratio of (5-15): (2-10): (40-80), the mixed solution is placed in (10-20) parts of triethylamine and refluxed overnight, the pH is adjusted to neutral, a white solid powder is obtained by filtering, and the powder is washed and dried to obtain an additive.

[0020] Preferably, the hole transport layer precursor solution is spin-coated on a glass / indium tin oxide substrate at a rotation speed of 3000-6000 rpm for 30-60 seconds, and annealed on a hot plate at 90-120° C. for 10-20 minutes.

[0021] Preferably, the perovskite precursor solution is spin-coated by an anti-solvent method, and the concentration of the perovskite precursor solution is 1.3 to 1.8 mol L -1 The perovskite precursor solution is spin-coated at a rotation speed of 4000-6000 rpm for 40-80 seconds, 110-200 μL of an organic solvent is added dropwise in the last 7-10 seconds, and annealed at 60-120° C. for 5-20 minutes to obtain a perovskite film.

[0022] Preferably, the organic solvent is chlorobenzene, ethyl acetate or anisole.

[0023] Preferably, the passivation layer material is one of 2-phenylethylamine hydrochloride, phenethylammonium iodide, phenethylammonium iodide or ethylenediamine hydroiodide.

[0024] Preferably, the passivation layer is spin-coated and annealed at 80-120° C. for 3-15 minutes.

[0025] Preferably, the electron transport layer material is C 60 , thickness is 15~30nm;

[0026] The barrier layer material is bathocuproin, and the thermal evaporation thickness is 3 to 8 nm;

[0027] The metal electrode is one of silver, gold or copper, and the thickness of the metal electrode is 80-120 nm.

[0028] Another aspect of the present invention provides a perovskite solar cell prepared by the above method based on controlling the crystallization of the perovskite film.

[0029] The present invention adopts the above technical solution, which has the following beneficial effects:

[0030] (1) High-quality perovskite film: The present invention adds an appropriate amount of additive molecules to the perovskite precursor solution, and the -OH group in the additive is fixed to the uncoordinated Pb 2+ ions, passivating iodine-lead antisite defects, alleviating hysteresis and reducing non-radiative recombination. In addition, C=O and -NH2 groups interact with formamidinium cations through hydrogen bonds, thereby alleviating residual strain and adjusting crystal orientation. As a result, the obtained perovskite film has fewer surface defects, larger average grain size and higher flatness.

[0031] (2) High stability: The high-quality perovskite film obtained by optimizing and controlling crystallization has a high barrier capacity for water and oxygen, so the prepared perovskite solar cell device has higher stability.

[0032] (3) Reduced current hysteresis: Thanks to the perovskite film with low defect density and high carrier concentration obtained by the additive optimization scheme, the current hysteresis of the prepared perovskite solar cell is reduced.

[0033] (4) High JV performance: The additive strategy is used to achieve defect passivation and crystallization regulation of the perovskite film, and the perovskite solar cell device invented and prepared exhibits higher open circuit voltage (1.20V), fill factor (84%) and photoelectric conversion efficiency (25.75%). BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute an improper limitation of the present invention. In the drawings:

[0035] Figure 1 The SEM images of the perovskite film prepared in a nitrogen atmosphere according to the present invention and the perovskite film prepared in a conventional manner;

[0036] Figure 2 It is a grazing incidence wide-angle X-ray scattering diagram of the perovskite film prepared in a nitrogen atmosphere of the present invention and the perovskite film prepared in a conventional manner;

[0037] Figure 3 It is a structural diagram of a perovskite solar cell device prepared in a nitrogen atmosphere according to the present invention;

[0038] Figure 4 is a JV curve diagram of the perovskite solar cell prepared in a nitrogen atmosphere according to the present invention and the perovskite solar cell prepared in a conventional manner;

[0039] Figure 5The graph is a curve showing the change of the photoelectric conversion efficiency of the perovskite solar cell prepared in a nitrogen atmosphere by the present invention and the perovskite solar cell prepared by a conventional method in a nitrogen atmosphere over time;

[0040] Figure 6 It is a dark current curve diagram of the perovskite solar cell prepared in a nitrogen atmosphere according to the present invention and the perovskite solar cell prepared in a traditional manner. DETAILED DESCRIPTION

[0041] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0042] The present invention provides a method for controlling the crystallization kinetics of perovskite for preparing a highly efficient and stable solar cell, comprising the following steps:

[0043] Step 1: The glass / indium tin oxide substrate is cleaned with soapy water, deionized water and ethanol in sequence, and ultrasonically treated for 20 minutes in each solution. The cleaned substrate is then treated with UV ozone for 15 minutes before use.

[0044] Step 2: Dissolve the hole transport layer material in ethanol solution to prepare 1.0 mg mL -1 concentration of hole transport layer precursor solution.

[0045] The hole transport layer material is (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1cyanovinyl)phosphonic acid, ethyl 2-[(2-chlorophenyl)(phenyl)amino]benzoate or (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid.

[0046] Step 3, dissolving cesium iodide, methylamine hydroiodide, formamidine hydroiodide, lead iodide and methylamine lead trichloride single crystal in a molar ratio of (0.03-0.05): (0.03-0.05): (0.70-0.90): (0.95-1.05): (0.04-0.06) in an organic solvent to obtain a mixed solution, and adding additives at a mass ratio of 1-5 mg per 1 mL of the mixed solution to prepare a perovskite precursor solution.

[0047] Wherein, the additive is prepared by mixing guanidine carbonate and 2-acetylbutyrolactone in anhydrous ethanol in a mass ratio of (5-15): (2-10): (40-80) and stirring. The mixed solution is placed in (10-20) parts of triethylamine and refluxed at 40-60° C. overnight. The suspension becomes yellow and turbid. After cooling, the pH is adjusted to 6-7 using a hydrochloric acid solution. The white solid powder is filtered, washed 3 times with ethanol, and dried to obtain the additive.

[0048] Step 4: dissolving the passivation layer material 2-phenylethylamine hydrochloride, phenethylamine iodide, phenethylamine iodide or ethylenediamine hydroiodide in an isopropanol solution to prepare a passivation layer precursor solution.

[0049] Step 5, spin-coat the hole transport layer precursor on the cleaned and treated transparent conductive glass, spin-coat it on the glass / indium tin oxide substrate at a rotation speed of 3000-6000 rpm for 30-60 seconds, and anneal on a hot plate at 90-120° C. for 10-20 minutes to obtain a hole transport layer.

[0050] Step 6: On the transparent conductive glass with the hole transport layer, a solution having a concentration of 1.3 to 1.8 mol L is spin-coated by an anti-solvent method. -1 The perovskite precursor solution is spin-coated at a rotation speed of 4000-6000 rpm for 40-80 seconds, 110-200 μL of an organic solvent such as chlorobenzene, ethyl acetate or anisole is added dropwise in the last 7-10 seconds, and annealed at 60-120° C. for 5-20 minutes to obtain a perovskite film. Figure 1 The SEM images of the perovskite film prepared in a nitrogen atmosphere according to the present invention and the perovskite film prepared in a conventional manner show that the perovskite film prepared in the present invention has a low defect state density and a smooth and dense surface.

[0051] Figure 2 The grazing-incidence wide-angle X-ray scattering diagram of the perovskite film prepared in a nitrogen atmosphere of the present invention and the perovskite film prepared in a conventional manner shows that the film prepared in the present invention has a stronger crystal orientation.

[0052] Step 7, spin-coating a passivation layer precursor solution on the transparent conductive glass deposited with the perovskite film, and annealing at 80-120° C. for 3-15 minutes to obtain a passivation layer.

[0053] The passivation layer material is one of 2-phenylethylamine hydrochloride, phenethylamine iodide, phenethylamine iodide or ethylenediamine hydroiodide.

[0054] Step 8: Vacuum thermally evaporate the electron transport layer material C with a thickness of 15 to 30 nm on the passivation layer. 60 .

[0055] Step 9, thermally evaporate a barrier layer material bathocuproin with a thickness of 3 to 8 nm and a metal electrode with a thickness of 80 to 120 nm on the electron transport layer material in sequence, where the metal electrode is silver, gold or copper, to obtain a perovskite solar cell.

[0056] Figure 3 This is a structural diagram of a perovskite solar cell device prepared in a nitrogen atmosphere according to the present invention.

[0057] The present invention is further described below through different embodiments.

[0058] Example 1

[0059] Step 1) The glass / indium tin oxide substrate was cleaned with soap water, deionized water and ethanol in sequence, ultrasonically treated in each solution for 20 minutes, and then the cleaned substrate was treated with ultraviolet ozone for 15 minutes before use.

[0060] Step 2) Dissolve the hole transport layer material (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphonic acid in ethanol solution to prepare 0.5 mg mL -1 concentration of hole transport layer precursor solution.

[0061] Step 3) Cesium iodide, methylamine hydroiodide, formamidine hydroiodide, lead iodide and methylamine lead trichloride single crystals are dissolved in an organic solvent chlorobenzene at a molar ratio of 0.03:0.05:0.70:1.05:0.05 to obtain a mixed solution, and additives are added at a mass ratio of 5 mg per 1 mL of the mixed solution to prepare a perovskite precursor solution.

[0062] The additive is prepared by mixing guanidine carbonate and 2-acetylbutyrolactone in anhydrous ethanol at a mass ratio of 10:7:80 and stirring; placing the mixture in 15 parts of triethylamine and refluxing at 60°C overnight. The suspension becomes yellow and turbid. After cooling, the pH is adjusted to 6-7 using a hydrochloric acid solution. The white solid powder is filtered, washed with ethanol three times, and dried to obtain the additive.

[0063] Step 4) dissolving the passivation layer material 2-phenylethylamine hydrochloride in an isopropanol solution to prepare a passivation layer precursor solution.

[0064] Step 5) Spin-coat the hole transport layer precursor solution on the cleaned and treated transparent conductive glass, spin-coat it on the glass / indium tin oxide substrate at a rotation speed of 4000 rpm for 50 seconds, and anneal it on a hot plate at 110° C. for 18 minutes to obtain a hole transport layer.

[0065] Step 6) On the transparent conductive glass with the hole transport layer, a 1.5 mol L -1 The perovskite precursor solution was spin-coated at a rotation speed of 5000 rpm for 60 seconds, 110 μL of organic solvent chlorobenzene was added dropwise in the last 10 seconds, and the film was annealed at 100° C. for 10 minutes to obtain a perovskite film.

[0066] Step 7) spin-coating a passivation layer precursor solution on the transparent conductive glass deposited with the perovskite film, and annealing at 80° C. for 15 minutes to obtain a passivation layer.

[0067] Step 8) Vacuum thermal evaporation of 20 nm thick electron transport layer material C on the passivation layer 60 .

[0068] Step 9) Thermally evaporate a barrier layer material bathocuproin with a thickness of 5 nm and a metal electrode gold with a thickness of 100 nm on the electron transport layer material in sequence to obtain a perovskite solar cell.

[0069] Under standard test conditions (AM1.5G illumination), the photoelectric conversion efficiency of the solar cell device prepared in this example is 25.75%, the open circuit voltage is 1.20V, and the short circuit current is 25.53mA / cm 2 , the filling factor is 84.04%.

[0070] Example 2

[0071] Step 1) The glass / indium tin oxide substrate was cleaned with soap water, deionized water and ethanol in sequence, ultrasonically treated in each solution for 20 minutes, and then the cleaned substrate was treated with ultraviolet ozone for 15 minutes before use.

[0072] Step 2) Dissolve the hole transport layer material 2-[(2-chlorophenyl)(phenyl)amino]benzoic acid ethyl ester in ethanol solution to prepare 0.8 mg mL -1 concentration of hole transport layer precursor solution.

[0073] Step 3) Cesium iodide, methylamine hydroiodide, formamidine hydroiodide, lead iodide and methylamine lead trichloride single crystals are dissolved in an organic solvent ethyl acetate at a molar ratio of 0.05:0.04:0.80:0.95:0.06 to obtain a mixed solution, and additives are added at a mass ratio of 1 mg per 1 mL of the mixed solution to prepare a perovskite precursor solution.

[0074] Preparation of the additive: Guanidine carbonate and 2-acetylbutyrolactone are mixed and stirred in anhydrous ethanol at a mass ratio of 15:2:60. The mixture is placed in 20 parts of triethylamine and refluxed at 50°C overnight. The suspension becomes yellow and turbid. After cooling, the pH is adjusted to 6-7 using a hydrochloric acid solution. A white solid powder is obtained by filtration, washed 3 times with ethanol, and dried to obtain the additive.

[0075] Step 4) dissolving the passivation layer material phenethylammonium iodide in an isopropanol solution to prepare a passivation layer precursor solution.

[0076] Step 5) Spin-coat the hole transport layer precursor solution on the cleaned and treated transparent conductive glass, spin-coat it on the glass / indium tin oxide substrate at a rotation speed of 3000 rpm for 60 seconds, and anneal it on a hot plate at 120° C. for 10 minutes to obtain a hole transport layer.

[0077] Step 6) On the transparent conductive glass with the hole transport layer, a 1.6 mol L -1The perovskite precursor solution was spin-coated at 6000 rpm for 40 seconds, 150 μL of organic solvent ethyl acetate was added dropwise at the last 8 seconds, and the film was annealed at 120° C. for 5 minutes to obtain a perovskite film.

[0078] Step 7) spin-coating a passivation layer precursor solution on the transparent conductive glass deposited with the perovskite film, and annealing at 100° C. for 8 minutes to obtain a passivation layer.

[0079] Step 8) Vacuum thermal evaporation of electron transport layer material C with a thickness of 15 nm on the passivation layer 60 .

[0080] Step 9) Thermally evaporate a barrier layer material bathocuproin with a thickness of 8 nm and a metal electrode silver with a thickness of 90 nm on the electron transport layer material in sequence to obtain a perovskite solar cell.

[0081] Under standard test conditions (AM1.5G illumination), the photoelectric conversion efficiency of the solar cell device prepared in this example is 25.18%, the open circuit voltage is 1.19V, and the short circuit current is 25.50mA / cm 2 , the filling factor is 83.63%.

[0082] Example 3

[0083] Step 1) The glass / indium tin oxide substrate was cleaned with soap water, deionized water and ethanol in sequence, ultrasonically treated in each solution for 20 minutes, and then the cleaned substrate was treated with ultraviolet ozone for 15 minutes before use.

[0084] Step 2) Dissolve the hole transport layer material (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid in ethanol solution to prepare 1.0 mg mL -1 concentration of hole transport layer precursor solution.

[0085] Step 3) Cesium iodide, methylamine hydroiodide, formamidine hydroiodide, lead iodide and methylamine lead trichloride single crystals are dissolved in an organic solvent anisole at a molar ratio of 0.04:0.03:0.90:0.10:0.04 to obtain a mixed solution, and additives are added at a mass ratio of 3 mg per 1 mL of the mixed solution to prepare a perovskite precursor solution.

[0086] The additive is prepared by mixing guanidine carbonate and 2-acetylbutyrolactone in anhydrous ethanol at a mass ratio of 5:10:40 and stirring; placing the mixture in 10 parts of triethylamine and refluxing at 40°C overnight. The suspension becomes yellow and turbid. After cooling, the pH is adjusted to 6-7 using a hydrochloric acid solution. A white solid powder is obtained by filtration, washed 3 times with ethanol, and dried to obtain the additive.

[0087] Step 4) dissolving the passivation layer material phenethylammonium iodide in an isopropanol solution to prepare a passivation layer precursor solution.

[0088] Step 5) Spin-coat the hole transport layer precursor solution on the cleaned and treated transparent conductive glass, spin-coat it on the glass / indium tin oxide substrate at a rotation speed of 5000 rpm for 40 seconds, and anneal it on a hot plate at 90° C. for 20 minutes to obtain a hole transport layer.

[0089] Step 6) On the transparent conductive glass with the hole transport layer, a 1.3 mol L -1 The perovskite precursor solution was spin-coated at 4500 rpm for 70 seconds, 200 μL of organic solvent anisole was added dropwise at the last 7 seconds, and the film was annealed at 80° C. for 12 minutes to obtain a perovskite film.

[0090] Step 7) spin-coating a passivation layer precursor solution on the transparent conductive glass deposited with the perovskite film, and annealing at 110° C. for 5 minutes to obtain a passivation layer.

[0091] Step 8) Vacuum thermal evaporation of 25 nm thick electron transport layer material C on the passivation layer 60 .

[0092] Step 9) Thermally evaporate a barrier layer material bathocuproin with a thickness of 3 nm and a metal electrode with a thickness of 80 nm on the electron transport layer material in sequence, where the metal electrode is silver, gold or copper, to obtain a perovskite solar cell.

[0093] Under standard test conditions (AM1.5G illumination), the photoelectric conversion efficiency of the solar cell device prepared in this example is 25.42%, the open circuit voltage is 1.20V, and the short circuit current is 25.46mA / cm 2 , the filling factor is 83.37%.

[0094] Example 4

[0095] Step 1) The glass / indium tin oxide substrate was cleaned with soap water, deionized water and ethanol in sequence, ultrasonically treated in each solution for 20 minutes, and then the cleaned substrate was treated with ultraviolet ozone for 15 minutes before use.

[0096] Step 2) Dissolve the hole transport layer material ethyl 2-[(2-chlorophenyl)(phenyl)amino]benzoate in ethanol solution to prepare 1.0 mg mL -1 concentration of hole transport layer precursor solution.

[0097] Step 3) Cesium iodide, methylamine hydroiodide, formamidine hydroiodide, lead iodide and methylamine lead trichloride single crystals are dissolved in an organic solvent chlorobenzene at a molar ratio of 0.035:0.05:0.85:1.05:0.05 to obtain a mixed solution, and additives are added at a mass ratio of 2 mg per 1 mL of the mixed solution to prepare a perovskite precursor solution.

[0098] Preparation of the additive: Guanidine carbonate and 2-acetylbutyrolactone are mixed and stirred in anhydrous ethanol at a mass ratio of 8:7:50. The mixture is placed in 18 parts of triethylamine and refluxed at 45°C overnight. The suspension becomes yellow and turbid. After cooling, the pH is adjusted to 6-7 using a hydrochloric acid solution. A white solid powder is obtained by filtration, washed 3 times with ethanol, and dried to obtain the additive.

[0099] Step 4) dissolving the passivation layer material ethylenediamine hydroiodide in an isopropanol solution to prepare a passivation layer precursor solution.

[0100] Step 5) Spin-coat the hole transport layer precursor solution on the cleaned and treated transparent conductive glass, spin-coat it on the glass / indium tin oxide substrate at a rotation speed of 6000 rpm for 30 seconds, and anneal it on a hot plate at 100° C. for 15 minutes to obtain a hole transport layer.

[0101] Step 6) On the transparent conductive glass with the hole transport layer, a 1.8 mol L -1 The perovskite precursor solution was spin-coated at 4000 rpm for 80 seconds, 180 μL of organic solvent chlorobenzene was added dropwise at the last 9 seconds, and the film was annealed at 60° C. for 20 minutes to obtain a perovskite film.

[0102] Step 7) spin-coating a passivation layer precursor solution on the transparent conductive glass deposited with the perovskite film, and annealing at 120° C. for 3 minutes to obtain a passivation layer.

[0103] Step 8) Vacuum thermally evaporate the electron transport layer material C with a thickness of 30 nm on the passivation layer. 60 .

[0104] Step 9) Thermally evaporate a barrier layer material bathocuproin with a thickness of 6 nm and a metal electrode copper with a thickness of 120 nm on the electron transport layer material in sequence to obtain a perovskite solar cell.

[0105] Under standard test conditions (AM1.5G illumination), the photoelectric conversion efficiency of the solar cell device prepared in this example is 25.62%, the open circuit voltage is 1.20V, and the short circuit current is 25.40mA / cm 2 , the filling factor is 83.05%.

[0106] Figure 4The JV curve diagram of the perovskite solar cell prepared in a nitrogen atmosphere of the present invention and the perovskite solar cell prepared in a conventional manner is shown; the perovskite solar cell device prepared by the present invention has a higher open circuit voltage, fill factor and photoelectric conversion efficiency. Figure 5 The graph is a curve showing the change in photoelectric conversion efficiency over time in nitrogen of the perovskite solar cell prepared by the present invention in a nitrogen atmosphere and the perovskite solar cell prepared by conventional methods. The unpackaged device prepared by the present invention has better storage stability. Figure 6 It is a dark current curve diagram of the perovskite solar cell prepared in a nitrogen atmosphere by the present invention and the perovskite solar cell prepared by conventional methods; the device prepared by the present invention has a lower dark current density.

[0107] It can be seen from the above examples that the photoelectric conversion efficiency of the perovskite solar cell prepared by the present invention is not less than 25.18%, the open circuit voltage is 1.19V, and the short circuit current is not higher than 25.53mA / cm 2 , the filling factor is not less than 83.05%. By synthesizing organic small molecules with different functional groups as additives, the crystallization and defects of perovskite films are adjusted through Michael addition reaction, and finally the quality of perovskite films is improved. And the inverse perovskite solar cells prepared according to this strategy have excellent photoelectric performance and stability.

[0108] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite film, characterized in that: The following steps are involved: (1) Cleaning the indium tin oxide transparent conductive glass substrate and treating it with ultraviolet ozone; (2) dissolving the hole transport layer material in an ethanol solution to prepare a hole transport layer precursor solution; (3) dissolving cesium iodide, methylamine hydroiodide, formamidine hydroiodide, lead iodide and methylamine lead trichloride single crystals in a molar ratio of (0.03-0.05):(0.03-0.05):(0.70-0.90):(0.95-1.05):(0.04-0.06) in an organic solvent to obtain a mixed solution, and adding an additive 2-ureido-4-pyrimidone at a mass ratio of 1-5 mg per 1 mL of the mixed solution to prepare a perovskite precursor solution; (4) dissolving the passivation layer material in an isopropanol solution to prepare a passivation layer precursor solution; (5) spin coating a hole transport layer precursor solution on the cleaned and treated transparent conductive glass, and annealing to obtain a hole transport layer; (6) Spin coating a perovskite precursor solution on a transparent conductive glass having a hole transport layer by an anti-solvent method, and obtaining a perovskite film after annealing; (7) spin coating a passivation layer precursor solution on the transparent conductive glass deposited with the perovskite film to form a passivation layer; (8) vacuum thermal evaporation of electron transport layer materials on the passivation layer; (9) Thermally evaporate a barrier layer material and a metal electrode in sequence on the electron transport layer material to obtain a perovskite solar cell.

2. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 1, characterized in that: The hole transport layer material is one of (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1cyanovinyl)phosphonic acid, ethyl 2-[(2-chlorophenyl)(phenyl)amino]benzoate or (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid.

3. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 1, characterized in that: The additive is prepared according to the following method: Guanidine carbonate and 2-acetylbutyrolactone are mixed with anhydrous ethanol in a mass ratio of (5-15): (2-10): (40-80), the mixed solution is placed in (10-20) parts of triethylamine and refluxed overnight, the pH is adjusted to neutral, a white solid powder is obtained by filtering, and the powder is washed and dried to obtain an additive.

4. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 1, characterized in that: The hole transport layer precursor solution is spin-coated on a glass / indium tin oxide substrate at a rotation speed of 3000-6000 rpm for 30-60 seconds, and annealed on a hot plate at 90-120° C. for 10-20 minutes.

5. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 1, characterized in that: The perovskite precursor solution was spin-coated using the anti-solvent method. The concentration of the perovskite precursor solution was 1.3-1.8 mol L -1 The perovskite precursor solution is spin-coated at a rotation speed of 4000-6000 rpm for 40-80 seconds, 110-200 μL of an organic solvent is added dropwise in the last 7-10 seconds, and annealed at 60-120° C. for 5-20 minutes to obtain a perovskite film.

6. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 5, characterized in that: The organic solvent is chlorobenzene, ethyl acetate or anisole.

7. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 1, characterized in that: The passivation layer material is one of 2-phenylethylamine hydrochloride, phenethylamine iodide, phenethylamine iodide or ethylenediamine hydroiodide.

8. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 1, characterized in that: Spin-coat the passivation layer and anneal at 80-120°C for 3-15 minutes.

9. The method for preparing a perovskite solar cell based on controlling the crystallization of a perovskite thin film according to claim 1, characterized in that: The electron transport layer material is C 60 , thickness is 15~30nm; The barrier layer material is bathocuproin, and the thermal evaporation thickness is 3 to 8 nm; The metal electrode is one of silver, gold or copper, and the thickness of the metal electrode is 80-120 nm.

10. A perovskite solar cell based on controlled perovskite film crystallization prepared by the method according to any one of claims 1 to 9.

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