Perovskite precursor solution, perovskite thin film, perovskite solar cell and preparation method

Abstract

The invention belongs to the photovoltaic field, and particularly relates to a perovskite precursor solution, a perovskite thin film, a perovskite solar cell and a preparation method. The perovskite precursor solution comprises a perovskite structure substance raw material, an organic additive and a solvent, the chemical formula of the organic additive is shown as a formula I; in the formula I, R1 is amino or acetamido, R2 is chlorine atom, and R3 is hydrogen atom, amino, acetamido, chlorine atom or hydroxyl. The chlorine atom, the pyridine ring and the acetamido (or amino) in the organic additive have a synergistic effect, so that the problems of uneven nucleation and multiple crystal defects of the perovskite thin film are solved, and the photovoltaic performance of the perovskite solar cell is further improved. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of photovoltaics, and in particular relates to a perovskite precursor solution, a perovskite film, a perovskite solar cell and a preparation method thereof. Background Art

[0002] As a new generation of photovoltaic technology, perovskite solar cells have developed rapidly in the past decade due to their advantages such as high efficiency, low cost and flexible preparation process. In recent years, the photoelectric conversion efficiency of perovskite solar cells has been close to that of traditional silicon-based cells, and has the potential to be widely used in photovoltaic power generation and portable electronic devices in the future. Although perovskite solar cells have made significant progress in improving efficiency, their stability remains the main bottleneck in commercial applications. On the one hand, perovskite materials are prone to degradation in air, moisture and light, resulting in a rapid decline in the performance of perovskite solar cells; on the other hand, perovskite films are susceptible to uneven nucleation and grain boundary defects during the preparation process, resulting in uneven film crystal quality, which in turn affects the efficiency and stability of perovskite solar cells. At present, in the field of perovskite solar cells, many researchers are exploring additive technology to improve the crystallization quality, interface properties and stability of perovskite films.

[0003] However, the existing technology still has the following problems and shortcomings: (1) Uneven nucleation and crystallization: Many current additive strategies still face the problems of uneven nucleation and unsatisfactory grain size distribution, resulting in unstable photoelectric properties of the film; (2) Interface defects: There are interface defects between the perovskite film and the electrode material. These defects will cause charge recombination and reduce the efficiency of the battery; (3) Stability issues: Although additives can improve the crystal quality of perovskite in the short term, some additives may cause a decrease in long-term stability, especially in humid and high temperature environments. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the perovskite precursor solution provided by the present invention contains an organic additive comprising chlorine atoms, pyridine rings and acetylamino groups. Through the synergistic effect of chlorine atoms, pyridine rings and acetylamino groups, the rapid nucleation of the perovskite film is promoted, the crystallization process of the perovskite film is optimized, the crystallization quality and stability are improved, the grain boundary defects are significantly reduced and the photoelectric conversion efficiency of the perovskite solar cell is improved.

[0005] Specifically, the present invention provides a perovskite precursor solution, wherein the perovskite precursor solution comprises a perovskite structural material raw material, an organic additive and a solvent; the chemical formula of the organic additive is shown in Formula I:

[0006]

[0007] In Formula I, R 1is amino or acetylamino, R 2 is a chlorine atom, R 3 It is a hydrogen atom, an amino group, an acetylamino group, a chlorine atom or a hydroxyl group.

[0008] In one or more embodiments, the organic additive is selected from one or more of 4-acetylamino-2-chloropyridine, 4-amino-2-chloropyridine, and 4-amino-2-chloropyridin-3-ol.

[0009] In one or more embodiments, the perovskite structure material raw material comprises AX and BX 2 ; A ion is selected from one or more of methylamine ion, formamidine ion, acetamidine ion, cesium ion and rubidium ion; B ion is selected from one or more of lead ion, tin ion, copper ion and germanium ion; X ion is selected from F - ,I - Br - , Cl - , BF 4 - PF 6 - and SCN - One or more of .

[0010] In one or more embodiments, the solvent is selected from one or more of dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dimethylpyrrolidone, 2-methoxyethanol, 1,3-dimethyl-3,4,5,6-tetrahydro-2-pyrimidinone, 1,3-dimethyl-2-imidazolidinone and γ-butyrolactone.

[0011] In one or more embodiments, the concentration of the perovskite structure material theoretically generated from the perovskite structure material raw material in the perovskite precursor solution is 1-2 mmol / mL.

[0012] In one or more embodiments, the concentration of the organic additive in the perovskite precursor solution is 0.1-5 mg / mL.

[0013] The invention provides a method for preparing a perovskite film, which comprises coating the perovskite precursor solution of the invention and then annealing to obtain the perovskite film.

[0014] In one or more embodiments, the coating method is slot coating, blade coating, spin coating, inkjet printing or screen printing.

[0015] The present invention provides a perovskite film prepared by the method of the present invention, wherein the perovskite film comprises a perovskite structural substance and an organic additive.

[0016] In one or more embodiments, the chemical formula of the perovskite structure material is ABX3 ; A ion is selected from one or more of methylamine ion, formamidine ion, acetamidine ion, cesium ion and rubidium ion; B ion is selected from one or more of lead ion, tin ion, copper ion and germanium ion; X ion is selected from F - ,I - Br - , Cl - , BF 4 - PF 6 - and SCN - One or more of .

[0017] In one or more embodiments, the perovskite film has a thickness of 0.5-1 μm.

[0018] The present invention provides a perovskite solar cell comprising the perovskite film of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a scanning electron microscope (SEM) image of the perovskite film prepared in Example 1 of the present invention.

[0020] Figure 2 This is a scanning electron microscope (SEM) image of the perovskite film prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0021] 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 the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0022] 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.

[0023] 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.

[0024] 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).

[0025] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0026] 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.

[0027] 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.

[0028] The present invention provides a perovskite precursor solution which may include a perovskite structural material raw material, an organic additive and a solvent; the chemical formula of the organic additive is shown in Formula I:

[0029]

[0030] In Formula I, R 1 It can be amino or acetylamino, R 2 It can be a chlorine atom, R 3 It can be a hydrogen atom, an amino group, an acetylamino group, a chlorine atom or a hydroxyl group. The organic additive of the present invention can contain a chlorine atom, a pyridine ring and an acetylamino group, or can contain a chlorine atom, a pyridine ring and an amino group. In some embodiments, the organic additive contains a chlorine atom, a pyridine ring and an acetylamino group, and the carbonyl group, the amino group, the chlorine atom and the pyridine ring group can be combined with Pb 2+ In some embodiments, the organic additive comprises a chlorine atom, a pyridine ring and an amino group, and the amino group, the chlorine atom and the pyridine ring group can react with Pb 2+ Coordination occurs and hydrogen bonding occurs with the organic component. Further, the organic additive can be one or more selected from 4-acetylamino-2-chloropyridine, 4-amino-2-chloropyridine and 4-amino-2-chloropyridine-3-ol. The use of the above-mentioned organic additives can effectively improve the quality of the perovskite film, thereby improving the photoelectric conversion efficiency and open circuit voltage of the perovskite solar cell.

[0031] In the present invention, the raw material of the perovskite structure material may include AX and BX 2 The A ion may be one or more selected from methylamine ion, formamidine ion, acetamidine ion, cesium ion and rubidium ion; the B ion may be one or more selected from lead ion, tin ion, copper ion and germanium ion; the X ion may be one or more selected from F - ,I - Br - , Cl - , BF 4 - PF 6 - and SCN - One or more of .

[0032] In some embodiments, the perovskite structure material raw material comprises AI and BI 2 The perovskite precursor solution may further include a second additive, which may be selected from MACl, PbCl 2 , FACl, CsCl, FABF 4 、FASCN、MASCN、Pb(SCN) 2 and PbI 2 In the present invention, the introduction of halogen or pseudo-halogen salt (second additive) containing perovskite ion components can improve the nucleation and crystallization process of perovskite.

[0033] In the present invention, the solvent may be selected from dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), acetonitrile (ACN), dimethylpyrrolidone (NMP), 2-methoxyethanol (2-Me), 1,3-dimethyl-3,4,5,6-tetrahydro-2-pyrimidone (DMPU), 1,3-dimethyl-2-imidazolidinone (DMI) and γ-butyrolactone (GBL) One or more. In the present invention, the volume ratio of DMF to NMP may be 10: (0.1-10), for example 10: 0.1, 10: 1, 10: 2, 10: 3, 10: 4, 10: 5, 10: 6, 10: 7, 10: 8, 10: 9, 10: 10.

[0034] In the present invention, the concentration of the perovskite structure material theoretically generated from the perovskite structure material raw material in the perovskite precursor solution can be 1-2 mmol / mL, for example, 1 mmol / mL, 1.2 mmol / mL, 1.4 mmol / mL, 1.6 mmol / mL, 1.8 mmol / mL, 2 mmol / mL.

[0035] In the present invention, the concentration of the organic additive in the perovskite precursor solution can be 0.1 mg / mL-5 mg / mL, preferably 0.5-1.5 mg / mL, such as 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL. In the present invention, the concentration of the organic additive is controlled within the above range, which can effectively improve the quality of the perovskite film and improve the photoelectric conversion efficiency and open circuit voltage of the perovskite solar cell.

[0036] The invention provides a method for preparing a perovskite film, which comprises coating the perovskite precursor solution of the invention and then annealing to obtain the perovskite film.

[0037] The preparation method of the present invention further comprises: filtering the perovskite precursor solution before coating.

[0038] In the present invention, the coating method can be slit coating, blade coating, spin coating, inkjet printing or screen printing. In the present invention, the coating speed can be 5-20 mm per second.

[0039] In the present invention, the annealing process is one-step annealing or two-step annealing.

[0040] The invention provides a perovskite film comprising a perovskite structural substance and an organic additive.

[0041] In the present invention, the chemical formula of the perovskite structure material is ABX 3 The A ion may be one or more selected from methylamine ion, formamidine ion, acetamidine ion, cesium ion and rubidium ion; the B ion may be one or more selected from lead ion, tin ion, copper ion and germanium ion; the X ion may be one or more selected from F - ,I - Br - , Cl - , BF 4 - PF 6 - and SCN - One or more of .

[0042] In the present invention, the thickness of the perovskite film may be 0.5-1 μm, for example, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm.

[0043] The present invention provides a perovskite solar cell comprising the perovskite film of the present invention. In the present invention, the perovskite solar cell may include a single-junction perovskite solar cell or a tandem perovskite solar cell; the perovskite solar cell may include a formal perovskite solar cell or an inverted perovskite solar cell. Specifically, the perovskite solar cell may be a formal single-junction perovskite solar cell, an inverted single-junction perovskite solar cell, a formal tandem perovskite solar cell, or an inverted tandem perovskite solar cell.

[0044] In the present invention, the formal single-junction perovskite solar cell may include a conductive substrate, an electron transport layer, a perovskite film, a hole transport layer and a back electrode in sequence. In the present invention, the inverted single-junction perovskite solar cell may include a conductive substrate, a hole transport layer, a perovskite film, an electron transport layer and a back electrode in sequence. In the present invention, the formal stacked perovskite solar cell may include a bottom electrode, a bottom cell, a tunneling layer, a formal perovskite top cell and a top electrode in sequence, and the positive top cell may include an electron transport layer, a perovskite film and a hole transport layer in sequence. In the present invention, the inverted stacked perovskite solar cell may include a bottom electrode, a bottom cell, a tunneling layer, an inverted perovskite top cell and a top electrode in sequence, and the inverted top cell may include a hole transport layer, a perovskite film and an electron transport layer in sequence.

[0045] In the present invention, the conductive substrate can be a flexible substrate or a rigid steel core, and the rigid substrate can be selected from indium tin oxide (ITO) transparent conductive glass, fluorine-doped tin oxide (FTO) transparent conductive glass, tungsten-doped indium oxide (IWO) transparent conductive glass and aluminum-doped zinc oxide (AZO) transparent conductive glass.

[0046] In the present invention, the hole transport layer can be a self-assembled molecule (SAM) and / or NiOx; the self-assembled molecule is selected from one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid and [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid.

[0047] The method for preparing a formal single-junction perovskite solar cell of the present invention comprises:

[0048] (1) depositing an electron transport layer on the surface of a conductive substrate;

[0049] (2) depositing a perovskite film on the surface of the electron transport layer;

[0050] (3) depositing a hole transport layer on the surface of the perovskite film;

[0051] (4) A back electrode is deposited on the surface of the hole transport layer to obtain a formal single-junction perovskite solar cell.

[0052] The method for preparing a transverse single-junction perovskite solar cell of the present invention comprises:

[0053] (1) depositing a hole transport layer on the surface of a conductive substrate;

[0054] (2) depositing a perovskite film on the surface of the hole transport layer;

[0055] (3) depositing an electron transport layer on the surface of the perovskite film;

[0056] (4) A back electrode is deposited on the surface of the electron transport layer to obtain an inverted single-junction perovskite solar cell.

[0057] The method for preparing a formal laminated perovskite solar cell of the present invention comprises:

[0058] (1) depositing a bottom electrode and a tunneling layer on both sides of the bottom cell;

[0059] (2) depositing an electron transport layer on the surface of the tunneling layer;

[0060] (3) depositing a perovskite film on the surface of the electron transport layer;

[0061] (4) depositing a hole transport layer on the surface of the perovskite film;

[0062] (5) Depositing a top electrode on the surface of the hole transport layer to obtain a formal laminated perovskite solar cell.

[0063] The method for preparing an inverted stacked perovskite solar cell of the present invention comprises:

[0064] (1) depositing a bottom electrode and a tunneling layer on both sides of the bottom cell;

[0065] (2) depositing a hole transport layer on the surface of the tunneling layer;

[0066] (3) depositing a perovskite film on the surface of the hole transport layer;

[0067] (4) depositing an electron transport layer on the surface of the perovskite film;

[0068] (5) A top electrode is deposited on the surface of the electron transport layer to obtain an inverted stacked perovskite solar cell.

[0069] Compared with the prior art, the present invention has the following beneficial effects:

[0070] (1) Improving the crystal quality of perovskite film: The chlorine atoms in the present invention react with Pb in the precursor solution to form a 2+ coordination, promoting the rapid nucleation of perovskite grains and forming a more uniform and dense crystal structure. This effect reduces the uneven nucleation phenomenon and significantly reduces grain boundary defects, thereby improving the photoelectric conversion efficiency of the film;

[0071] (2) Improve interfacial bonding and reduce charge recombination: The lone pair of electrons in the pyridine ring can react with Pb 2 + The coordination occurs, effectively passivating the uncoordinated metal ions at the grain boundaries, reducing interface defects and inhibiting charge recombination. This effect significantly improves the open circuit voltage and fill factor of the device, ultimately improving the photoelectric performance of the battery;

[0072] (3) Improving the long-term stability of the device: The carbonyl and amino groups in the acetylamino group interact with the organic cations (such as MA+ or FA+) in the perovskite material through hydrogen bonds, further stabilizing the perovskite crystal structure, enhancing the stability of the material in humid and high-temperature environments, and extending the service life of the battery; the amino group can interact with the unsaturated ions or defects in the perovskite material through its unshared electron pairs, such as forming hydrogen bonds or coordination bonds, thereby passivating the defect sites to reduce non-radiative recombination centers and reduce carrier recombination losses; in addition, the hydrophilicity of the amino group can improve the moisture resistance of the perovskite film to a certain extent, thereby improving the wet-heat stability of the device.

[0073] (4) Environmentally friendly and low-cost additives: Compared with some high-cost additives that require complex synthesis, the organic additives used in the present invention are relatively simple and easy to obtain, and have good environmental friendliness, which meets the requirements of low-cost mass production of perovskite solar cells in the future.

[0074] 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.

[0075] Example 1

[0076] In this embodiment, the perovskite film is prepared, and the specific steps are as follows:

[0077] Preparation of perovskite precursor solution: FAI, PbI 2 , CsI three kinds of perovskite structural material raw materials, molar weight is PbI 2 10% MACl (methylammonium chloride) and a molar amount of PbI 2 5% PbCl 2Mix, then add 1 mg of 4-acetylamino-2-chloropyridine as an organic additive, add it into 1 mL of DMF and NMP with a volume ratio of 4:1 to dissolve, and obtain the theoretically generated Cs 0.1 FA 0.9 PbI 3 The concentration of the perovskite precursor solution is 1.5 mol / L;

[0078] (1) Conductive substrate pretreatment: The FTO glass is laser-scribed by P1, then cleaned and dried with nitrogen to obtain a clean conductive substrate;

[0079] (2) Preparation of hole transport layer: NiOx was sputtered on a clean conductive substrate by PVD method to obtain a NiOx layer with a thickness of 15 nm; a self-assembled molecular layer precursor solution (solute: MeO-4PACz, solute concentration: 0.5 mg / mL, solvent: ethanol) was deposited on the surface of the NiOx layer by slit coating method to obtain a self-assembled molecular layer with a thickness of 3 nm. The NiOx layer and the self-assembled molecular layer together constituted a hole transport layer;

[0080] (3) Preparation of perovskite film: In an air environment, the above-configured perovskite precursor solution is coated on the hole transport layer through slit coating; in the slit coating process, the coating height is 100 μm, the coating liquid output is set to 300 μL, the plunger pump injection speed is 1 μL / s, the platform movement speed is adjusted to 10 mm / s, the preparation environment temperature is 25±5°C, and the environment humidity is 20±5% RH; after the coating is completed to form a perovskite wet film, the wet film is immediately moved to a vacuum extraction chamber for vacuum drying, the vacuum pressure is 5 Pa, the vacuum time is 30 s, and the dried film is placed on a hot stage set at a temperature of 130°C for annealing for 30 min to obtain a perovskite film with a thickness of 600 nm.

[0081] Comparative Example 1

[0082] The other conditions of this comparative example are the same as those of Example 1, except that the perovskite precursor solution of this comparative example does not contain the organic additive 4-acetylamino-2-chloropyridine.

[0083] Test Example 1

[0084] The perovskite films prepared in Example 1 and Comparative Example 1 were tested by scanning electron microscopy. Figure 1 This is a scanning electron microscope image (SEM) of the perovskite film prepared in Example 1 of the present invention. Figure 2 This is a scanning electron microscope image (SEM) of the perovskite film prepared in Comparative Example 1 of the present invention. Figure 1 and Figure 2 It can be seen that the grains of the perovskite film without the organic additive of the present invention grow unevenly and unevenly, and there are many residual PbI2 , which will lead to additional defects and affect the interface carrier transport; while the growth of the perovskite film grains containing the organic additive of the present invention is more uniform and dense, which is conducive to the interface carrier transport, and the residual PbI 2 Distributing at the grain boundaries can effectively passivate defects, ultimately significantly improving device performance.

[0085] Example 2

[0086] This embodiment prepares a perovskite solar cell, and the specific steps are as follows:

[0087] Preparation of perovskite precursor solution: FAI, PbI 2 , CsI three kinds of perovskite structural material raw materials, molar weight is PbI 2 10% MACl (methylammonium chloride) and a molar amount of PbI 2 5% PbCl 2 Mix, then add 0.5 mg of 4-acetylamino-2-chloropyridine as an organic additive, add it into 1 mL of DMF and NMP with a volume ratio of 4:1 to dissolve, and obtain the theoretically generated Cs 0.1 FA 0.9 PbI 3 The concentration of the perovskite precursor solution is 1.5 mol / L;

[0088] (1) Conductive substrate pretreatment: The FTO glass is laser-scribed by P1, then cleaned and dried with nitrogen to obtain a clean conductive substrate;

[0089] (2) Preparation of hole transport layer: NiOx was sputtered on a clean conductive substrate by PVD method to obtain a NiOx layer with a thickness of 15 nm; a self-assembled molecular layer precursor solution (solute: MeO-4PACz, solute concentration: 0.5 mg / mL, solvent: ethanol) was deposited on the surface of the NiOx layer by slit coating method to obtain a self-assembled molecular layer with a thickness of 3 nm. The NiOx layer and the self-assembled molecular layer together constituted a hole transport layer;

[0090] (3) Preparation of perovskite film: In an air environment, the above-prepared perovskite precursor solution is coated on the hole transport layer through slit coating; in the slit coating process, the coating height is 100 μm, the coating liquid output is set to 300 μL, the plunger pump injection speed is 1 μL / s, the platform movement speed is adjusted to 10 mm / s, the preparation environment temperature is 25±5°C, and the environment humidity is 20±5% RH; after the coating is completed to form a perovskite wet film, the wet film is immediately moved to a vacuum extraction chamber for vacuum drying, the vacuum pressure is 5 Pa, the vacuum time is 30 s, and the dried film is placed on a hot stage set at a temperature of 130°C for annealing for 30 min to obtain a perovskite film with a thickness of 600 nm;

[0091] (4) Preparation of electron transport layer: Vacuum evaporation was used to deposit a 30 nm thick C60 layer, a 20 nm thick SnO layer, and a 2 layer, C60 layer and SnO 2 The layers together constitute the electron transport layer, and laser P2 scribing is performed immediately after the electron transport layer is prepared;

[0092] (5) Preparation of back electrode: Cu with a thickness of 120 nm was evaporated on the electron transport layer by vacuum evaporation to obtain a back electrode, and laser P3 scribing and P4 edge cleaning were performed to obtain a perovskite solar cell module.

[0093] Example 3

[0094] The other conditions of this embodiment are the same as those of Embodiment 2, except that the content of the organic additive 4-acetylamino-2-chloropyridine in the perovskite precursor solution of this embodiment is 1 mg.

[0095] Example 4

[0096] The other conditions of this embodiment are the same as those of Embodiment 2, except that the content of the organic additive 4-acetylamino-2-chloropyridine in the perovskite precursor solution of this embodiment is 1.5 mg.

[0097] Example 5

[0098] The other conditions of this embodiment are the same as those of Embodiment 3, except that the organic additive in the perovskite precursor solution of this embodiment is 4-amino-2-chloropyridine.

[0099] Example 6

[0100] The other conditions of this embodiment are the same as those of Embodiment 3, except that the organic additive in the perovskite precursor solution of this embodiment is 4-amino-2-chloropyridine-3-ol.

[0101] Comparative Example 2

[0102] The other conditions of this comparative example are the same as those of Example 2, except that the perovskite precursor solution of this comparative example does not contain the organic additive 4-acetylamino-2-chloropyridine.

[0103] Comparative Example 3

[0104] The other conditions of this embodiment are the same as those of embodiment 3, except that the organic additive in the perovskite precursor solution of this embodiment is 2-acetylamino-4-methylpyridine.

[0105] Comparative Example 4

[0106] The other conditions of this embodiment are the same as those of Embodiment 3, except that the organic additive in the perovskite precursor solution of this embodiment is 2-amino-4-bromopyridine.

[0107] Test Example 2

[0108] Performance test of perovskite solar cells: At 25°C and AM 1.5G standard solar spectrum, a solar simulator was used to set the voltage range to 0.2-12V, and the current output of the perovskite solar cells prepared in Examples 2-6 and Comparative Examples 2-4 at different voltages was tested, and the corresponding current-voltage (IV) characteristic curves were plotted, where the cell surface area was 49cm 2 , the incident light power (Pin) is 100mW / cm 2 The performance (open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency) of the perovskite solar cells prepared in Examples 2-6 and Comparative Examples 2-4 were obtained according to the characteristic curves.

[0109] (1) Open circuit voltage (Voc): The voltage value corresponding to when the current is equal to zero.

[0110] (2) Short-circuit current density (Jsc): The current value when the voltage is zero is the short-circuit current (Isc), and the current per unit battery surface area is the short-circuit current density.

[0111] (3) Fill factor (FF): The ratio of the maximum output power (Pmax) of the battery to the product of the open circuit voltage and the short circuit current. The calculation formula is (Pmax / Voc*Isc), where the maximum power point is the point where the battery output power reaches its maximum value.

[0112] (4) Photoelectric conversion efficiency (PCE): Photoelectric conversion efficiency refers to the ratio of maximum output power to incident light power (Pin), and the calculation formula is (Pmax / Pin)*100%.

[0113] The test results of the open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency of the perovskite solar cells prepared in Example 2-6 and Comparative Example 2-4 are shown in Table 1.

[0114] Table 1: Open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency of perovskite solar cells prepared in Examples 2-6 and Comparative Examples 2-4

[0115]

[0116]

[0117] As shown in Table 1, compared with the perovskite solar cell without organic additives prepared in Comparative Example 2, the performance of the perovskite solar cells with organic additives prepared in Examples 2-6 is significantly improved, especially V OC The maximum increase was nearly 100 mV, which shows that the organic additive proposed in the present invention can significantly reduce the defect state density of perovskite, improve the crystallization quality, and the prepared perovskite solar cell has excellent device performance.

[0118] Compared with the perovskite solar cells prepared with additives added to Comparative Examples 3 and 4, the performance of the perovskite solar cells prepared with the organic additives of the present invention in Examples 2-6 is significantly improved, which indicates that the organic additives of the present invention are beneficial to improving the performance of the perovskite solar cells.

Claims

1. A perovskite precursor solution, characterized in that: The perovskite precursor solution comprises a perovskite structural material raw material, an organic additive and a solvent; the chemical formula of the organic additive is shown in Formula I: In formula I, R1 is an amino group or an acetylamino group, R2 is a chlorine atom, and R3 is a hydrogen atom, an amino group, an acetylamino group, a chlorine atom or a hydroxyl group.

2. The perovskite precursor solution according to claim 1, characterized in that The organic additive is selected from one or more of 4-acetylamino-2-chloropyridine, 4-amino-2-chloropyridine and 4-amino-2-chloropyridine-3-ol.

3. The perovskite precursor solution according to claim 1, characterized in that The perovskite precursor solution has one or more of the following characteristics: The raw materials of the perovskite structure material include AX and BX2; the A ion is selected from one or more of methylamine ion, formamidine ion, acetamidine ion, cesium ion and rubidium ion; the B ion is selected from one or more of lead ion, tin ion, copper ion and germanium ion; the X ion is selected from F - ,I - Br - , Cl - 、BF4 - PF6 - and SCN - One or more of; The solvent is selected from one or more of dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dimethylpyrrolidone, 2-methoxyethanol, 1,3-dimethyl-3,4,5,6-tetrahydro-2-pyrimidinone, 1,3-dimethyl-2-imidazolidinone and γ-butyrolactone.

4. The perovskite precursor solution according to claim 3, characterized in that The theoretical concentration of the perovskite structure material generated by the perovskite structure material raw material in the perovskite precursor solution is 1-2 mmol / mL; and / or The concentration of the organic additive in the perovskite precursor solution is 0.1-5 mg / mL.

5. A method for preparing a perovskite film, characterized in that: The method comprises coating the perovskite precursor solution according to any one of claims 1 to 4, and then annealing to obtain a perovskite film.

6. The method according to claim 5, characterized in that The coating method is slit coating, blade coating, spin coating, inkjet printing or screen printing.

7. A perovskite film prepared by the method of claim 5 or 6, characterized in that: The perovskite film comprises a perovskite structural material and an organic additive.

8. The perovskite film according to claim 7, characterized in that The chemical formula of the perovskite structure material is ABX3; the A ion is selected from one or more of methylamine ion, formamidine ion, acetamidine ion, cesium ion and rubidium ion; the B ion is selected from one or more of lead ion, tin ion, copper ion and germanium ion; the X ion is selected from F - ,I - Br - , Cl - 、BF4 - PF6 - and SCN - One or more of .

9. The perovskite film according to claim 7, characterized in that The thickness of the perovskite film is 0.5-1 μm.

10. A perovskite solar cell comprising the perovskite thin film according to any one of claims 7 to 9.

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