Solar cell, photovoltaic module, power generation device and electric device

Abstract

A solar cell and a preparation method therefor, a perovskite precursor solution, a photovoltaic module, a power generation device and an electric device. The solar cell comprises a perovskite light-absorbing layer, which comprises perovskite grains, wherein the proportion of the number of perovskite grains having a grain size of 1 μm to 3 μm in the perovskite grains is greater than or equal to 90%. The perovskite grains in the solar cell have a moderate grain size, and the uniformity thereof is improved; therefore, the stability and photoelectric performance of the solar cell can be improved.

Description

Solar cells, photovoltaic modules, power generation devices and power consumption devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on Chinese patent application numbered 202410407303.9, filed on April 3, 2024, and entitled “Solar cells, photovoltaic modules, power generation devices, and power-using devices,” and claims the priority of the Chinese patent application. The entire contents of the Chinese patent application are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a solar cell and a preparation method thereof, a perovskite precursor solution, a photovoltaic module, a power generation device, and an electricity-consuming device. Background Art

[0004] In recent years, global energy shortages and environmental pollution have become increasingly prominent. As an ideal renewable energy source, solar cells have received increasing attention. Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric effect or photochemical effect.

[0005] Perovskite solar cells (PSCs) are solar cells that use perovskite as a light-absorbing material. Compared with other solar cells, perovskite solar cells stand out in the solar cell field due to their low cost, high efficiency, and simple processing.

[0006] However, the poor stability and low photoelectric performance of perovskite solar cells in related technologies have hindered their practical application and industrial development. Therefore, how to improve the photoelectric performance of perovskite solar cells remains a technical problem that needs to be solved urgently.

[0007] Summary of the Invention

[0008] The present disclosure is made in response to the above-mentioned problems and aims to provide a solar cell and its preparation method, a perovskite precursor solution, a photovoltaic module, a power generation device, and a power consumption device. The perovskite grains in the solar cell have a moderate grain size and improved uniformity, thereby improving the stability and photoelectric performance of the solar cell.

[0009] A first aspect of the present disclosure provides a solar cell comprising a perovskite light-absorbing layer; the perovskite light-absorbing layer comprises perovskite grains, wherein the perovskite grains have a grain size of 1 μm to 3 μm, accounting for greater than or equal to 90%. The perovskite light-absorbing layer of the solar cell disclosed herein has grains of moderate size. This reduces overall defects in the perovskite light-absorbing layer and the likelihood of carrier capture at grain boundaries, thereby reducing non-radiative recombination and improving the stability and photoelectric performance of the solar cell.

[0010] In some embodiments, the number of perovskite grains with a grain size of 2 μm±0.2 μm accounts for greater than or equal to 40%. The grain size in the perovskite light absorption layer of the present disclosure is relatively consistent.

[0011] In some embodiments, the number of perovskite grains with a grain size of 2 μm ± 0.2 μm accounts for greater than or equal to 50%. The grain size of the perovskite light absorption layer of the present disclosure is more concentratedly distributed around 2 μm, which further makes the quality of the perovskite light absorption layer more uniform, the carrier transmission is smoother, and the film stability is further improved.

[0012] In some embodiments, the roughness of the perovskite light-absorbing layer is between 30 nm and 70 nm. A roughness within this range indicates a more uniform thickness, a smoother surface, smoother carrier transport, and improved film stability. Furthermore, a roughness within this range facilitates the formation of other functional layers on the perovskite light-absorbing layer, improving the coverage of the functional layers on the perovskite light-absorbing layer and enhancing the overall performance of the solar cell.

[0013] In some embodiments, the thickness uniformity of the perovskite light absorbing layer is less than 5%, where the thickness uniformity is calculated by the following formula: (maximum value - minimum value) / (maximum value + minimum value). A thickness uniformity within the above range indicates that the perovskite light absorbing layer has a more uniform thickness, a smoother surface, smoother carrier transport, and further improved film stability.

[0014] In some embodiments, at least a portion of the perovskite grains having a grain size of 1 μm to 3 μm extend through the thickness of the perovskite light absorbing layer. Having a majority of the perovskite grains in the perovskite light absorbing layer extend through the entire thickness of the perovskite light absorbing layer can reduce the likelihood of carrier recombination at perovskite grain boundaries, thereby further improving the photoelectric conversion efficiency of the perovskite light absorbing layer.

[0015] In some embodiments, the perovskite grains include one of the compound represented by formula (I) and the compound represented by formula (II): [A] [B] [X] 3 (I); [A] 2 [C] [D] [X] 6 (II);

[0016] Wherein, A comprises at least one of an inorganic monovalent cation and an organic monovalent cation;

[0017] B includes inorganic divalent cations;

[0018] C includes inorganic monovalent cations;

[0019] D includes inorganic trivalent cations;

[0020] X includes an anion.

[0021] The perovskite light-absorbing layer provided in the present disclosure is applicable to the above-mentioned perovskite materials. Therefore, it can be seen that the perovskite light-absorbing layer provided in the present disclosure has a wide range of applications and can be applied to common perovskite materials in the art.

[0022] In some embodiments, A comprises (NR1R2R3R4) + 、(R1R2N=CR3R4) + 、(R1R2N-C(R5)=NR3R4) + 、(R1R2N-C(NR5R6)=NR3R4) + 、Li + 、Na + , K + , Rb + 、Cs + , wherein R1, R2, R3, R4, R5 and R6 are each independently selected from H, substituted or unsubstituted C1-C20 alkyl or substituted or unsubstituted aromatic group;

[0023] B includes Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Pd 2+ 、Yb 2+ 、Eu 2+ At least one of;

[0024] C includes Li + 、Na + , K + , Rb + 、Cs+ 、Cu + 、Ag + 、Au + 、Hg + At least one of;

[0025] D includes Bi 3+ 、Sb 3+ Cr 3+ 、Fe 3+ 、Co 3+ 、Ga 3+ 、As 3+ 、Ru 3+ , Rh 3+ 、In 3+ 、Ir 3+ 、Au 3+ 、Al 3+ At least one of;

[0026] X includes F - 、Cl - Br - , I - 、SCN - 、CNO - 、OCN - 、OSCN - SH - OH - 、CN - 、SeCN - At least one of .

[0027] In some embodiments, the solar cell further includes a first electrode disposed on one side of the perovskite light absorbing layer, a second electrode disposed on the other side of the perovskite light absorbing layer, a first carrier transport layer disposed between the first electrode and the perovskite light absorbing layer; and a second carrier transport layer disposed between the perovskite light absorbing layer and the second electrode;

[0028] The first carrier transport layer is an electron transport layer or a hole transport layer; the second carrier transport layer is an electron transport layer or a hole transport layer, but is different from the first carrier transport layer. The first and second carrier transport layers can enhance the dissociation effect of electrons and holes.

[0029] A second aspect of the present disclosure provides a perovskite precursor solution, the perovskite precursor solution comprising a solvent, a perovskite precursor raw material, a viscosity modifier and a complexing agent;

[0030] The complexing agent includes at least one of thiosemicarbazide, acetylthiourea, 3-aminopropanesulfonic acid, benzylthiamine, and benzenesulfonylacetic acid;

[0031] The viscosity modifier includes at least one of phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid, serine phospholipid, potassium chloride ammonium, lead thiocyanate, and urea.

[0032] In the present disclosure, the perovskite precursor solution includes a viscosity modifier and a complexing agent. The complexing agent can react with anions (e.g., I - ) acts to a certain extent, thereby limiting the crystallization of the perovskite precursor raw material, which is beneficial for obtaining uniform perovskite grains. Furthermore, the introduction of a viscosity modifier helps adjust the viscosity of the solution, regulate the number of nuclei formed, and increase the size of the perovskite grains. The combination of a viscosity modifier and a complexing agent can produce a perovskite light-absorbing layer with moderate grain size and relatively uniformity.

[0033] In some embodiments, the molar percentage of the complexing agent is 0.1% to 1% based on the molar amount of the target cation in the perovskite precursor raw material;

[0034] The perovskite crystals formed from the perovskite precursor solution include one of the compound represented by formula (I) and the compound represented by formula (II): [A][B][X]3 (I); [A]2[C][D][X]6 (II);

[0035] Wherein, A comprises at least one of an inorganic monovalent cation and an organic monovalent cation;

[0036] B includes inorganic divalent cations;

[0037] C includes inorganic monovalent cations;

[0038] D includes inorganic trivalent cations;

[0039] X includes anions,

[0040] The target cation is an inorganic divalent cation at the B site or the target cation is an inorganic trivalent cation at the C site.

[0041] By controlling the molar percentage of the complexing agent within the above range, it is beneficial to further improve the uniformity of the perovskite grains.

[0042] In some embodiments, A comprises (NR1R2R3R4) + 、(R1R2N=CR3R4) + 、(R1R2N-C(R5)=NR3R4) + 、(R1R2N-C(NR5R6)=NR3R4) + 、Li + 、Na + , K + , Rb + 、Cs+ , wherein R1, R2, R3, R4, R5 and R6 are each independently selected from H, substituted or unsubstituted C1-C20 alkyl or substituted or unsubstituted aromatic group;

[0043] B includes Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Pd 2+ 、Yb 2+ 、Eu 2+ At least one of;

[0044] C includes Li + 、Na + , K + , Rb + 、Cs + 、Cu + 、Ag + 、Au + 、Hg + At least one of;

[0045] D includes Bi 3+ 、Sb 3+ Cr 3+ 、Fe 3+ 、Co 3+ 、Ga 3+ 、As 3+ 、Ru 3+ , Rh 3+ 、In 3+ 、Ir 3+ 、Au 3+ 、Al 3+ At least one of;

[0046] X includes F - 、Cl - Br - , I - 、SCN - 、CNO - 、OCN - 、OSCN - SH - OH- 、CN - 、SeCN - At least one of .

[0047] In some embodiments, the mole percentage of the complexing agent is 0.2% to 0.6% based on the molar amount of the target cation.

[0048] In some embodiments, the molar percentage of the viscosity modifier is 1% to 5% based on the molar amount of the target cation in the perovskite precursor raw material. By controlling the viscosity modifier percentage within the above range, it is advantageous to further adjust the number of perovskite grains with a grain size of 1 μm to 3 μm.

[0049] In some embodiments, the mole percentage of the viscosity modifier is 1.5% to 3.5% based on the molar amount of the target cation.

[0050] In some embodiments, the solvent includes at least one of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0051] A third aspect of the present disclosure provides a method for preparing a solar cell, the method comprising forming a perovskite light-absorbing layer, wherein forming the perovskite light-absorbing layer comprises the following steps:

[0052] Providing a perovskite precursor solution of the second aspect;

[0053] Coating a perovskite precursor solution on a substrate to form a perovskite precursor wet film,

[0054] Vacuum flash evaporation of perovskite precursor wet films, and

[0055] Heat treatment is performed to obtain a perovskite light-absorbing layer.

[0056] In some embodiments, the heat treatment is annealing at a temperature of 100° C. to 230° C. for 10 minutes to 60 minutes.

[0057] The method for preparing a solar cell disclosed herein uses the perovskite precursor solution provided by the present disclosure, and thus has at least the same advantages as the perovskite precursor solution.

[0058] A fourth aspect of the present disclosure provides a photovoltaic assembly, comprising the solar cell according to the first aspect of the present disclosure or the solar cell prepared according to the method of the third aspect of the present disclosure.

[0059] A fifth aspect of the present disclosure provides a photovoltaic device comprising the photovoltaic assembly of the fourth aspect of the present disclosure.

[0060] The photovoltaic module, power generation device, and power consumption device disclosed herein include the solar cell provided by the disclosure, and thus have at least the same advantages as the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] FIG1 shows a schematic structural diagram of a solar cell according to an embodiment of the present disclosure.

[0062] FIG2 shows a schematic structural diagram of a solar cell according to an embodiment of the present disclosure.

[0063] FIG3 is a scanning electron microscope (SEM) image of the structure obtained in step (3) of Example 1.

[0064] FIG4 is a cross-sectional SEM image of the structure obtained in step (3) of Example 1 in the thickness direction.

[0065] Figure 5 is a SEM image of the structure obtained in step (3) in Comparative Example 1.

[0066] FIG6 is a cross-sectional SEM image of the structure obtained in step (3) in Comparative Example 1 in the thickness direction.

[0067] Explanation of reference numerals: 10, 100: solar cell; 11: first electrode; 12: second electrode; 13: perovskite light absorbing layer; 141: hole transport layer; 142: electron transport layer. DETAILED DESCRIPTION

[0068] Below, with appropriate reference to the accompanying drawings, a detailed description of the embodiments of a solar cell and its preparation method, a perovskite precursor solution, a photovoltaic module, a power generation device, and an electric device disclosed in the present invention is specifically disclosed. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter described in the claims.

[0069] " scope " disclosed in the present disclosure is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and selected lower limit and upper limit define the boundary of special scope.The scope that this mode limits can be to include end value or not include end value, and can be combined arbitrarily, and promptly any lower limit can form a scope with any upper limit combination.For example, if the scope of 60-120 and 80-110 is listed for specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.In addition, if the minimum range value 1 and 2 listed, and if the maximum range value 3,4 and 5 listed, then the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.In the present disclosure, unless otherwise specified, numerical range " ab " represents the abbreviation of any real number combination between a and b, and wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0070] Unless otherwise specified, all embodiments and optional embodiments of the present disclosure can be combined with each other to form new technical solutions.

[0071] Unless otherwise specified, all technical features and optional technical features disclosed herein can be combined with each other to form a new technical solution.

[0072] Unless otherwise specified, all steps of the present disclosure may be performed sequentially or randomly, preferably sequentially. For example, a method comprising steps (a) and (b) indicates that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, a method further comprising step (c) indicates that step (c) may be added to the method in any order, for example, the method may comprise steps (a), (b), and (c), or may comprise steps (a), (c), and (b), or may comprise steps (c), (a), and (b), etc.

[0073] Unless otherwise specified, the terms used in the present disclosure have the common meanings that are generally understood by those skilled in the art.

[0074] Unless otherwise specified, the numerical values ​​of the parameters mentioned in the present disclosure can be tested using various test methods commonly used in the art, for example, they can be tested according to the test methods given in the present disclosure.

[0075] In this disclosure, the term "electrode" means a region or layer consisting of or consisting essentially of an electrode material.

[0076] As used herein, the term "layer" refers to any substantially layered structure. A layer may have a thickness that varies over the range of the layer. Typically, a layer has an approximately constant thickness. As used herein, the term "thickness" of a layer refers to the average thickness of the layer. The thickness of a layer can be measured by conventional methods in the art.

[0077] Unless otherwise specified, the term "disposed on" means that one component is provided or disposed on another component. A first component may be provided or disposed directly on a second component, or a third component may be interposed between the first and second components. For example, if a first layer is provided on a second layer, this includes the presence of a third layer interposed between the first and second layers.

[0078] As used herein, the term "perovskite material" refers to a material having a three-dimensional crystal structure related to that of CaTiO3, or a material including a layer having a structure related to that of CaTiO3. Upon receiving incident light, electrons in the perovskite material are excited, transitioning from the valence band to the conduction band, generating electron-hole pairs.

[0079] Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric or photochemical effect. Perovskite solar cells (PSCs) use perovskite materials as light-absorbing materials. Compared to other solar cells, perovskite solar cells have higher photoelectric conversion efficiency. Unless otherwise specified, a solar cell refers to a solar cell whose light-absorbing layer contains perovskite materials. This term may also be referred to as a perovskite solar cell.

[0080] The solar cell includes a first electrode (the electrode that first receives the incident light), a perovskite light-absorbing layer, and a second electrode (the electrode that last receives the incident light) which are sequentially arranged along the direction of light incidence.

[0081] The photoelectric conversion principle of solar cells is as follows: incident light (for example, sunlight) enters the device from the first electrode, then reaches the perovskite light-absorbing layer and is absorbed by it. Under the excitation of the incident light, the perovskite light-absorbing layer generates hole-electron pairs. Under the action of the electric field, the holes and electrons are separated, and the electrons are transferred to one electrode while the holes are transferred to the other electrode. Then, a loop is formed through the external circuit, which can be used to drive the load.

[0082] During the fabrication of perovskite light-absorbing layers for solar cells, the crystallization process is difficult to control, resulting in low crystallinity, numerous grain defects, or excessively small grains. These defects, along with excessive grain boundaries, easily trap carriers, causing non-radiative recombination between electrons and holes, which directly impacts the cell's photoelectric conversion efficiency. This problem is particularly pronounced when fabricating large-area perovskite light-absorbing layers.

[0083] Several methods have been proposed for preparing perovskite light-absorbing layers to form larger grains, thereby reducing defects within the grains and improving the quality of the perovskite light-absorbing layer. For example, vacuum flash evaporation of wet perovskite films has been proposed to rapidly evaporate the solvent, promote nucleation and grain growth, and reduce internal defects. However, this method often results in a high concentration of small grains at the grain boundaries, resulting in unsatisfactory perovskite light-absorbing layer quality. To address this, methods have been proposed to further increase the grain size, resulting in perovskite light-absorbing layers with a majority (over 90%) of grains within the 3μm-5μm range. However, overly large perovskite grains are prone to internal cracks. While such films appear intact when viewed from above, a longitudinal cross-section reveals cracks within many grains. These "large grains" do not actually penetrate the film longitudinally and, instead, impair carrier transport. Furthermore, the large grain boundaries between perovskite grains make carriers more susceptible to trapping at these boundaries during transport, leading to increased non-radiative recombination. At the same time, due to the large number of vacancies at the grain boundaries, the perovskite light-absorbing layer is prone to degradation, resulting in a decrease in the stability of the battery.

[0084] Based on this, the present disclosure provides a solar cell and its preparation method, a perovskite precursor solution, a photovoltaic module, a power generation device, and a power consumption device. The perovskite light-absorbing layer of the solar cell disclosed herein has moderately sized grains, and the grain size is relatively uniform. This reduces overall defects in the perovskite light-absorbing layer and the likelihood of carrier capture at grain boundaries, thereby reducing non-radiative recombination and improving the stability and photoelectric performance of the solar cell. The various aspects of this disclosure are described in detail below with reference to specific embodiments.

[0085] solar cells

[0086] A first aspect of the present disclosure provides a solar cell comprising a perovskite light absorption layer. The perovskite light absorption layer comprises perovskite grains, wherein the perovskite grains have a grain size of 1 μm to 3 μm and account for greater than or equal to 90%.

[0087] The majority (over 90%) of perovskite grains have a grain size between 1 μm and 3 μm. This moderate grain size in the perovskite light-absorbing layer prevents defects caused by a large number of small grains, as well as excessive large grains that could lead to cracks within the grains and excessive grain boundaries that could increase non-radiative recombination of carriers.

[0088] The “grain size” of perovskite mentioned in this article refers to the particle size of the grains observed from above the perovskite light-absorbing layer.

[0089] The perovskite light absorbing layer 13 includes a plurality of perovskite grains.

[0090] The percentage (ω) of perovskite grains having a grain size of 1 μm to 3 μm in the perovskite grains is greater than or equal to 90%. Optionally, 90% ≤ ω ≤ 95%. For example, ω is 90%, 92%, 93%, 95%, or a range between any two values, but is not limited thereto.

[0091] In some embodiments, the number of perovskite grains with a grain size of 2 μm ± 0.2 μm accounts for (σ) greater than or equal to 40%. Optionally, σ is greater than or equal to 50%, σ is greater than or equal to 60%, and σ is greater than or equal to 70%. For example, σ is 40%, 50%, 60%, 70%, 80%, 90%, or a value between the ranges consisting of any two values. This reflects that the grain size in the perovskite light absorption layer of the present disclosure is more concentratedly distributed around 2 μm, which further makes the quality of the perovskite light absorption layer more uniform, the carrier transmission is smoother, and the film stability is further improved.

[0092] Various aspects of the solar cell disclosed herein are further described below with reference to the accompanying drawings.

[0093] 1 shows a schematic structural diagram of a solar cell according to an embodiment of the present disclosure. The solar cell 10 includes a first electrode 11 , a second electrode 12 , and a perovskite light absorbing layer 13 disposed between the first electrode 11 and the second electrode 12 .

[0094] In some embodiments, the first electrode 11 serves as a bottom electrode (transparent electrode) and first receives incident light. In this embodiment, the material used for the first electrode 11 may include a transparent conductive material. The present disclosure does not particularly limit the transparent conductive material included in the first electrode 11. Exemplarily, the transparent conductive material includes at least one of tin oxide, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), antimony-doped tin oxide, indium-doped tungsten oxide (IWO), and graphene.

[0095] In some embodiments, the second electrode 12 serves as a top electrode, and incident light is emitted from the second electrode 12 outside the solar cell. In this embodiment, the material used for the second electrode 12 may include a conductive material. The present disclosure does not particularly limit the conductive material included in the second electrode 12. For example, the conductive material includes at least one of the above-mentioned transparent conductive materials, metals and alloys thereof, and carbon elemental materials. Exemplarily, the metals and alloys thereof include at least one of gold (Au), silver (Ag), copper (Cu), and aluminum (Al). Exemplarily, the carbon elemental material includes at least one of graphite, graphene, and carbon nanotubes.

[0096] In other embodiments, other functional layers may be present between the perovskite light absorbing layer 13 and the first and / or second electrodes, including but not limited to, for example, a carrier transport layer, a carrier blocking layer, a passivation layer, and the like.

[0097] In some embodiments, the roughness of the perovskite light absorbing layer is 30 nm to 70 nm, optionally, the roughness is 40 nm to 60 nm. For example, the roughness is 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, or a value between the ranges consisting of any two values, but is not limited thereto. The roughness within the above range reflects that the thickness of the perovskite light absorbing layer is more uniform, the surface is smoother, the carrier transport is smoother, and the film stability is further improved. In addition, the roughness within the above range is conducive to further forming other functional layers on the perovskite light absorbing layer, which can improve the coverage of the functional layer on its upper surface and improve the overall performance of the solar cell.

[0098] In some embodiments, the thickness uniformity of the perovskite light absorbing layer is that the thickness uniformity of the perovskite light absorbing layer is 5% or less. Optionally, the thickness uniformity is 4% or less. The thickness uniformity is calculated by the following formula: (maximum value - minimum value) / (maximum value + minimum value), wherein the maximum value and the minimum value refer to the maximum thickness value and the minimum thickness value of the perovskite light absorbing layer, respectively. For example, the thickness uniformity is 5%, 4%, 3%, 2%, 1% or a value between the ranges consisting of any two values, but is not limited thereto. The thickness uniformity is within the above range, reflecting that the thickness of the perovskite light absorbing layer is more uniform, the surface is smoother, the carrier transmission is smoother, and the film stability is further improved.

[0099] In some embodiments, the boundaries of perovskite grains having a grain size of 1 μm to 3 μm have perovskite grains having a grain size of less than 1 μm.

[0100] In some embodiments, the perovskite grains have a grain size less than 1 μm and account for less than 10% of the perovskite grains.

[0101] In some embodiments, at least a portion of the perovskite grains having a grain size of 1 μm to 3 μm extend through the thickness of the perovskite light absorbing layer. Having a majority of the perovskite grains in the perovskite light absorbing layer extend through the entire thickness of the perovskite light absorbing layer can reduce the likelihood of carrier recombination at perovskite grain boundaries, thereby further improving the photoelectric conversion efficiency of the perovskite light absorbing layer.

[0102] In some embodiments, the thickness of the perovskite light absorbing layer is 200 nm to 1000 nm, optionally 300 nm to 600 nm.

[0103] The above-mentioned morphology of the perovskite grains in the perovskite light-absorbing layer can be observed using a scanning electron microscope (SEM). For example, after forming the perovskite light-absorbing layer on the substrate, the surface of the perovskite light-absorbing layer can be observed using an SEM. Referring to FIG3 , an SEM photograph of the upper surface of the perovskite light-absorbing layer prepared according to step (3) of Example 1 below is shown. From FIG3 , it can be directly observed that the grain size is large and relatively uniform, and there are very few small grains. By measuring the particle size of each grain, the proportion of the number of grains within a certain area can be calculated.

[0104] The roughness of the perovskite light absorbing layer can be measured by conventional methods in the art, for example, by using an atomic force microscope (Bruker Dimension Icon Edge series atomic force microscope, Dimension).

[0105] The thickness uniformity of the perovskite light absorbing layer can be measured by conventional methods in the art. For example, a step profiler (BRUKER Dektak XT) can be used for testing. 18 points are selected for testing on each perovskite light absorbing layer. Based on these 18 data points, the following formula is used:

[0106] Thickness uniformity = (maximum value - minimum value) / (maximum value + minimum value), perform thickness uniformity test.

[0107] The uniformity of the perovskite light absorbing layer can be determined by testing the luminescence of the perovskite light absorbing layer (e.g., luminescence intensity) using a photoluminescence scanning system (PLmapping). Ultimately, the uniformity of the perovskite light absorbing layer can be determined based on the luminescence intensity of the perovskite light absorbing layer.

[0108] In addition, a cross-sectional SEM photograph of the perovskite light absorbing layer in the thickness direction can also be obtained using a scanning electron microscope. See Figure 4, which shows a cross-sectional SEM photograph of the perovskite light absorbing layer in the thickness direction prepared in step (3) of Example 1 below. Figure 4 shows the morphology of the grains in the thickness direction, where the grains extend throughout the entire film layer in the thickness direction of the perovskite light absorbing layer, the interfaces between the grains are generally perpendicular to the film plane, and the crystal size is relatively uniform.

[0109] In some embodiments, the perovskite light absorbing layer is composed of perovskite grains.

[0110] The present disclosure does not particularly limit the type of material for the perovskite light-absorbing layer. In some embodiments, the perovskite grains include one of the compounds represented by the general structural formulae (I) and (II): [A][B][X]3(I); [A]2[C][D][X]6(II). Wherein, A includes at least one of an inorganic monovalent cation and an organic monovalent cation; B includes an inorganic divalent cation; C includes an inorganic monovalent cation; D includes an inorganic trivalent cation; and X includes an anion. The perovskite light-absorbing layer provided in the present disclosure is applicable to the above-mentioned perovskite materials. It can be seen that the perovskite light-absorbing layer of the present disclosure has a wide range of applications and can be applied to common perovskite materials in the art.

[0111] For example, the A-site ion may be an organic monovalent cation comprising (NR1R2R3R4) + 、(R1R2N=CR3R4) + 、(R1R2N-C(R5)=NR3R4) + , or (R1R2N-C(NR5R6)=NR3R4) + At least one of, wherein R1, R2, R3, R4, R5 and R6 are each independently selected from H, substituted or unsubstituted C1-C20 alkyl or substituted or unsubstituted aromatic. Optionally, the organic monovalent cation is (H2N=CH-NH2) + (abbreviated as FA) and / or CH3NH3 + (abbreviated as MA).

[0112] For example, the A-site ion or C-site ion may be an inorganic monovalent cation, which includes Li + 、Na + , K + , Rb + 、Cs + 、Cu + 、Ag + 、Au + and Hg + At least one of .

[0113] Exemplarily, the B-site ion may be an inorganic divalent cation, which includes Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+、Fe 2+ 、Co 2+ 、Ni 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Pd 2+ 、Yb 2+ 、Eu 2+ Optionally, the inorganic divalent cation is Pb 2+ .

[0114] For example, the D-site ion may be an inorganic trivalent cation, which includes Bi 3+ 、Sb 3+ Cr 3+ 、Fe 3+ 、Co 3+ 、Ga 3+ 、As 3+ 、Ru 3+ , Rh 3+ 、In 3+ 、Ir 3+ 、Au 3+ and Al 3+ Optionally, the inorganic trivalent cation is Bi 3+ .

[0115] Exemplarily, the X anion includes F - 、Cl - Br - , I - 、SCN - 、CNO - 、OCN - 、OSCN - SH - OH - 、CN - and SeCN - At least one of. Optionally, the anion is Br - and / or I - .

[0116] In some embodiments, the perovskite grains are exemplified by Cs 0.17 FA 0.83 PbI 3、 Cs 0.05 FA 0.95 PbI3、MA 0.05 FA 0.95 PbI3、Cs 0.05 MA 0.05 FA 0.9 PbI3、Cs 0.05 MA 0.05 FA0.9 Pb(I 0.9 Br 0.1 )3, etc., but not limited to these.

[0117] The present disclosure does not impose any particular limitation on the band gap of the perovskite light absorbing layer 13, and the band gap of the perovskite light absorbing layer 13 commonly used in the art can be adopted. For example, the band gap of the perovskite light absorbing layer 13 can be in the range of 1.20 eV-2.30 eV.

[0118] In the present disclosure, the band gap measurement method is not particularly limited. Exemplarily, the band gap measurement method may include first obtaining an ultraviolet absorption curve through ultraviolet absorption spectrum testing; and then calculating the band gap of the perovskite light absorbing layer 13 using the Tauc equation.

[0119] The present disclosure does not particularly limit the thickness of the perovskite light absorption layer 13, and the thickness of the perovskite light absorption layer 13 commonly used in the art can be used. For example, the thickness of the perovskite light absorption layer 13 is in the range of 200 nm to 1000 nm.

[0120] In some embodiments, the solar cell further includes a first carrier transport layer disposed between the first electrode and the perovskite light absorbing layer; and a second carrier transport layer disposed between the perovskite light absorbing layer and the second electrode; wherein the first carrier transport layer is an electron transport layer or a hole transport layer; and the second carrier transport layer is an electron transport layer (ETL) or a hole transport layer (HTL), but is different from the first carrier transport layer. The provision of the first and second carrier transport layers can enhance the dissociation effect of electrons and holes.

[0121] In the present disclosure, the electron transport layer has the function of transporting electrons, and is used to transport the electrons generated by the excitation of the perovskite light absorbing layer 13 to the adjacent electrode, and prevent the electrons from diffusing in the opposite direction.

[0122] The present disclosure does not specifically limit the electron transport material used in the electron transport layer, and the electron transport materials commonly used in the art can be used. For example, the electron transport material includes at least one of imide compounds, quinone compounds, fullerenes, metal oxides, semiconductor material oxides, titanates, fluorides and their derivatives and materials obtained by doping or passivation. Exemplarily, the imide compound includes at least one of phthalimide, succinimide, N-bromosuccinimide, glutarimide or maleimide. Fullerene and its derivatives include [6,6]-phenyl C 61 Methyl butyrate (PC61BM), [6,6]-phenyl C 71 Methyl butyrate (PC71BM), fullerene C 60 (C 60 ), Fullerene C 70 (C70 ). Exemplarily, the quinone compound includes at least one of benzoquinone, naphthoquinone, phenanthrenequinone or anthraquinone. Exemplarily, the metal element in the metal oxide includes at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga and Cr. Optionally, the metal oxide includes at least one of tin dioxide (SnO2), zinc oxide (ZnO), titanium dioxide (TiO2). Exemplarily, the semiconductor material oxide includes silicon oxide. Exemplarily, the titanate includes at least one of strontium titanate and calcium titanate. Exemplarily, the fluoride includes at least one of lithium fluoride and calcium fluoride.

[0123] The present disclosure does not impose any particular limitation on the thickness of the electron transport layer, and the thickness of the electron transport layer conventionally used in the art can be adopted. For example, the thickness of the electron transport layer is 5 nm to 60 nm.

[0124] In the present disclosure, the hole transport layer has the function of extracting and transporting holes, and is used to transport the holes generated by the perovskite light absorption layer 13 to the adjacent electrodes and prevent the holes from diffusing in the opposite direction.

[0125] The present disclosure does not particularly limit the hole transport material used in the hole transport layer, and hole transport materials commonly used in the art can be used. Exemplary hole transport materials include poly [bis (4-phenyl) (2,4,6-trimethylphenyl) amine] (PTAA), 2,2',7,7'-tetrakis [N,N-di (4-methoxyphenyl) amino] -9,9'-spirobifluorene (Spiro-OMeTAD), poly-3 hexylthiophene (P3HT), triphenylamine with triptycene as the core (H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N- (4-phenylamino) carbazole-spirobifluorene (CzPAF-SBF), a mixture of poly 3,4-ethylenedioxythiophene and polystyrene sulfone (PEDOT-PSS), polythiophene, nickel oxide, molybdenum oxide, cuprous iodide, cuprous oxide and its derivatives and at least one of the materials obtained by doping or passivation thereof.

[0126] The present disclosure does not impose any particular limitation on the thickness of the hole transport layer, and the thickness of the hole transport layer conventionally used in the art can be adopted. For example, the thickness of the hole transport layer is 10 nm to 200 nm.

[0127] Figure 2 shows a schematic diagram of the structure of a solar cell according to one embodiment of the present disclosure. In this embodiment, the solar cell 100 includes a first electrode 11, a hole transport layer 141, a perovskite light absorption layer 13, an electron transport layer 142, and a second electrode 12, which are sequentially arranged along the direction of light incidence. In this embodiment, the first electrode 11, the hole transport layer 141, the perovskite light absorption layer 13, the electron transport layer 142, and the second electrode 12 are as described above and are not further described here.

[0128] Those skilled in the art will understand that FIG2 merely exemplifies that the hole transport layer 141 is disposed on the side of the perovskite light absorbing layer 13 facing the first electrode 11, and the electron transport layer 142 is disposed on the side of the perovskite light absorbing layer 13 facing the second electrode 12. In some embodiments, the positions of the hole transport layer 141 and the electron transport layer 142 may be interchanged, that is, the electron transport layer 142 is disposed on the side of the perovskite light absorbing layer 13 facing the first electrode 11, and the hole transport layer 141 is disposed on the side of the perovskite light absorbing layer 13 facing the second electrode 12.

[0129] Perovskite precursor solution

[0130] A second aspect of the present disclosure also provides a perovskite precursor solution for preparing the perovskite light-absorbing layer in the aforementioned solar cell. The perovskite precursor solution includes a solvent, a perovskite precursor raw material, a viscosity modifier, and a complexing agent. The complexing agent includes at least one of thiosemicarbazide, acetylthiourea, 3-aminopropanesulfonic acid, benzylthiamine, and sulfonylacetic acid. The viscosity modifier includes at least one of phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid, serine phospholipids, potassium chloride ammonium, lead thiocyanate, and urea.

[0131] In the present disclosure, the perovskite precursor solution is used to prepare the perovskite light absorbing layer including the perovskite grains, which includes a viscosity modifier and a complexing agent. The complexing agent can react with the anions (e.g., I - ) acts to a certain extent, thereby limiting the crystallization of the perovskite precursor raw material, which is beneficial for obtaining uniform perovskite grains. Furthermore, the introduction of a viscosity modifier helps adjust the viscosity of the solution, regulate the number of nuclei formed, and increase the size of the perovskite grains. The combination of a viscosity modifier and a complexing agent can produce a perovskite light-absorbing layer with moderate grain size and relatively uniformity.

[0132] In the present disclosure, a solvent is used to dissolve the perovskite precursor raw materials, viscosity modifier, and complexing agent. The present disclosure does not impose any particular limitation on the solvent; any solvent capable of dissolving the perovskite precursor raw materials, viscosity modifier, and complexing agent is sufficient. In some embodiments, the solvent includes at least one of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP).

[0133] In some embodiments, the solvent comprises a mixed solvent of DMF and DMSO in a volume ratio of 2: 1. In some embodiments, the solvent comprises a mixed solvent of DMF and DMSO in a volume ratio of 4: 1.

[0134] In some embodiments, the mole percentage of the complexing agent is 0.1% to 1% based on the molar amount of the target cation in the perovskite precursor raw material.

[0135] Wherein, the target cation is an inorganic divalent cation at position B in the above-defined formula (I) [A] [B] [X] 3 ; or an inorganic trivalent cation at position C in the above-defined formula (II) [A] 2 [C] [D] [X] 6 . The definitions of formula (I) and formula (II) are not repeated here.

[0136] Optionally, the mole percentage of the complexing agent is 0.2%-0.6%. For example, the mole percentage of the complexing agent is 0.1%, 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, 0.3%, 0.32%, 0.34%, 0.36%, 0.38%, 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, 0.52%, 0.54%, 0.56%, 0.58%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or a range between any two values. By controlling the mole percentage of the complexing agent within the above range, the uniformity of the perovskite grains is further improved.

[0137] In some embodiments, the molar percentage of the viscosity modifier is 1% to 5% based on the molar amount of the target cation in the perovskite precursor raw material. Alternatively, the molar percentage of the viscosity modifier is 1.5% to 3.5%. For example, the molar percentage of the viscosity modifier is 1%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 4%, 5%, or a range between any two values. By controlling the viscosity modifier percentage within the above range, it is helpful to further adjust the number of perovskite grains with a grain size of 1 μm to 3 μm.

[0138] In some embodiments, the corresponding perovskite precursor raw material can be selected according to the type of perovskite material of the desired perovskite light absorbing layer. For example, the predetermined perovskite material is FA 0.83 Cs 0.17 PbI3, the perovskite precursor raw materials may include PbI2, FAI and CsI in a corresponding molar ratio (1.2:1:0.2).

[0139] Those skilled in the art will understand that the present disclosure is merely an exemplary introduction to several types of perovskite precursor raw materials and the addition amounts of the perovskite precursor raw materials. The above description does not constitute a special limitation. Those skilled in the art can select the corresponding types of perovskite precursor raw materials and the addition amounts of the perovskite precursor raw materials according to the required perovskite grains.

[0140] Method for preparing solar cell

[0141] A third aspect of the present disclosure further provides a method for preparing a solar cell. The method includes forming a perovskite light-absorbing layer, wherein forming the perovskite light-absorbing layer includes the following steps:

[0142] Providing the perovskite precursor solution of the second aspect above;

[0143] coating a perovskite precursor solution on a substrate to form a perovskite precursor wet film;

[0144] Vacuum flash evaporation of perovskite precursor wet films, and

[0145] Heat treatment is performed to obtain a perovskite light-absorbing layer.

[0146] The present disclosure does not impose any particular limitation on the coating method of the perovskite precursor solution. For example, the perovskite precursor solution can be coated by spin coating, slit coating, blade coating, or the like.

[0147] In some embodiments, the substrate may be an electrode, a carrier transport layer, or other functional layer that is in contact with and stacked with the perovskite light absorbing layer. The present disclosure is not limited to a specific substrate.

[0148] In some embodiments, after coating the perovskite wet film on the substrate, a vacuum flash process is performed in a high-temperature thermal evaporation coating (VCD) device. The vacuum flash process can rapidly evaporate the solvent, which is beneficial for nucleation and crystal growth.

[0149] In some embodiments, the heat treatment is performed at a temperature of 100° C. to 230° C. for 10 to 60 minutes. For example, the heat treatment temperature is 100° C., 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., 210° C., 220° C., 230° C., or a range consisting of any two values. For example, the heat treatment time (annealing time) is 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, or a range consisting of any two values.

[0150] The preparation methods of the other functional layers of the solar cell (first electrode, second electrode, carrier transport layer, carrier blocking layer, passivation layer, etc.) are not particularly limited and may include methods commonly used in the art, such as spin coating, spray coating, slit coating, chemical bath deposition, electrochemical deposition, chemical vapor deposition, physical epitaxial growth, vacuum thermal evaporation, atomic layer deposition, magnetron sputtering, and mechanical pressing.

[0151] The present disclosure also provides a photovoltaic module, including the solar cell provided in the above embodiment. In some embodiments, the photovoltaic module further includes a welding ribbon connecting multiple solar cells, a junction box for current transmission, and a battery packaging component.

[0152] In some embodiments, the battery packaging component includes photovoltaic glass. The photovoltaic glass covers the solar cells and protects them. Photovoltaic glass also has excellent light transmittance and high hardness, making it adaptable to large temperature swings between day and night and adverse weather conditions.

[0153] In some embodiments, the battery packaging component includes an ethylene-vinyl acetate copolymer (EVA) film, which is disposed between the photovoltaic glass and the solar cell to bond the photovoltaic glass and the solar cell.

[0154] In some embodiments, the battery packaging component includes a photovoltaic backsheet, which protects the solar cells.

[0155] Optionally, the material of the photovoltaic backsheet may include a polyvinyl fluoride composite film or a thermoplastic elastic material. The material of the photovoltaic backsheet has the properties of insulation, waterproofness, and aging resistance.

[0156] In some embodiments, the battery packaging component includes a solar aluminum frame, which is made of aluminum alloy and has the characteristics of high strength and corrosion resistance, and can support and protect the solar cell.

[0157] The present disclosure also provides a power generation device, comprising the solar cell provided in the above embodiment.

[0158] The present disclosure also provides an electrical device including the solar cell provided in the above embodiment.

[0159] In some embodiments, the electrical device includes lighting equipment, energy storage equipment, etc., and the embodiments of the present disclosure include but are not limited to the same. For example, the electrical device includes a solar water heater, a solar street light, a solar photovoltaic generator, etc.

[0160] Example

[0161] The following examples are provided. The examples described below are illustrative and are intended only to explain the present disclosure and are not to be construed as limiting the present disclosure. Unless otherwise specified, all reagents used were commercially available and all equipment used was conventional.

[0162] Example 1

[0163] A solar cell was prepared by the following steps.

[0164] (1) Providing a First Electrode: A 30 cm × 30 cm sheet of TCO conductive glass (fluorine-doped SnO2 conductive glass) was scribed P1 to form a 70 μm wide P1 channel that penetrated the first electrode. The TCO glass was then cleaned using a cleaning machine. The TCO conductive glass was cleaned sequentially with a conductive glass cleaning solution, deionized water, and anhydrous ethanol.

[0165] (2) Providing a hole transport layer:

[0166] A nickel oxide thin film is deposited as a hole transport layer using a magnetron sputtering machine. After cleaning the TCO conductive glass, dust is blown off the surface with an air gun. The TCO conductive glass is then placed face-up in the loading area. The chamber temperature is set to 150°C, the sputtering power to 2.5 kW, and the oxygen-argon ratio to 1.5%, and the coating process begins. After the process is complete, a nickel oxide film with a thickness of approximately 30 nm is obtained.

[0167] (3) Providing a perovskite light-absorbing layer:

[0168] Preparation of perovskite precursor solution: Weigh 1.2 mol of PbI2, 1.0 mol of FAI, 0.2 mol of CsI, 0.024 mol of phosphatidylcholine and 0.0048 mol of thiosemicarbazide, dissolve in 1 L of a mixed solvent formed by N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 2:1), and stir at room temperature until completely dissolved to obtain a perovskite precursor solution.

[0169] Coating process: A wet film of the perovskite precursor solution was applied to the substrate obtained in step (2). The wet film thickness was 5 μm and the coating speed was 50 mm / s. The direction of the grooves in the P1 scribe line was perpendicular to the coating blade and aligned with the coating direction.

[0170] Solvent quenching method: After coating, immediately remove the substrate from the coater and place it in the VCD chamber. After the VCD runs for 100 seconds at room temperature, open the air inlet valve to break the vacuum. After opening the cover, immediately transfer the substrate coated with the perovskite wet film to the oven and anneal at 140°C for 20 minutes.

[0171] (4) Provide electron transport layer: vacuum evaporation C 60

[0172] Place the substrate on the deposition table of the vacuum evaporation equipment and wait until the vacuum degree drops to 5*10 -4 Pa below, 30nm C was evaporated on the perovskite light absorbing layer at a rate of 0.05A / s. 60 as an electron transport layer.

[0173] (5) P2 laser etching

[0174] A green laser was used for laser etching to form a P2 channel that penetrates the electron transport layer, perovskite light absorption layer, and hole transport layer. The P2 channel is 60μm wide and free of residue, and avoids the P1 channel.

[0175] (6) Providing the second electrode: Place the laminate obtained in step (5) into the evaporation machine and wait until the vacuum degree drops to 5×10 -4 Pa or less, on the electron transport layer, 80 nm of metallic copper (Cu) was evaporated at a rate of 0.1 A / s as a second electrode, thereby obtaining the solar cell of Example 1.

[0176] (7) P3 laser etching

[0177] A green laser is used to scribe the P3 channel that penetrates the electron transport layer, perovskite light absorption layer, hole transport layer, and second electrode. The P3 channel is 20 μm wide and avoids the P1 and P2 channels.

[0178] (8) P4 laser etching

[0179] Using a green laser, a 10 mm wide P4 trench is scribed around the laminate obtained in step (7). The P4 trench penetrates the second electrode, the electron transport layer, the perovskite light absorption layer, the hole transport layer, and the first electrode. The internal and external resistance of P4 is greater than 10 MΩ.

[0180] Testing of perovskite grain morphology

[0181] A surface SEM photograph of the perovskite light-absorbing layer prepared in step (3) of Example 1 was collected using a scanning electron microscope (HR-TEM Talos F200), as shown in FIG3 . The scale bar in FIG3 allows the measurement of the particle size of each grain. Based on the particle size of each grain, it can be calculated that the number of perovskite grains ranging from 1 μm to 3 μm accounts for 93%, and the number of perovskite grains ranging from 2 μm ± 0.2 μm accounts for 71%.

[0182] A cross-sectional SEM photograph of the perovskite light absorbing layer prepared in step (3) of Example 1 in the thickness direction was collected using a scanning electron microscope (SEM), as shown in Figure 4. As can be seen from Figure 4, in the perovskite light absorbing layer obtained in Example 1, the perovskite grains penetrate the perovskite light absorbing layer in the thickness direction of the perovskite light absorbing layer, and the interior of the crystals is uniform and free of cracks.

[0183] The same test method as in Example 1 was used to test Comparative Example 1, and the test results obtained are shown in Figures 5 and 6.

[0184] As can be seen from FIG5 , in the perovskite light-absorbing layer obtained in Comparative Example 1, the number of perovskite grains ranging from 1 μm to 3 μm accounts for 72%, and the number of perovskite grains ranging from 2 μm±0.2 μm accounts for only 22%.

[0185] As can be seen from FIG6 , in the perovskite light-absorbing layer obtained in Comparative Example 1, cracks exist inside the grains.

[0186] Roughness test of perovskite light absorbing layer

[0187] The perovskite absorption layer obtained in step (3) of Example 1 was measured using a shape meter (MarSurf, model: M300C mobile roughness meter) according to the industrial standard IPC-TM-650 2.2.17. The test results are shown in Table 1-1.

[0188] Testing the thickness uniformity of the perovskite light absorbing layer

[0189] A step profiler (BRUKER Dektak XT) was used to measure the thickness uniformity of the perovskite absorber layer obtained in step (3) of Example 1 at 18 selected locations. The thickness uniformity of the perovskite absorber layer was determined based on the equation: thickness uniformity = (maximum thickness - minimum thickness) / (maximum thickness + minimum thickness). The test results are shown in Table 1-1.

[0190] Example 2

[0191] A solar cell was prepared according to the method of Example 1, except that:

[0192] In step (3), 0.024 mol of phosphatidylcholine is replaced by 0.024 mol of urea.

[0193] The perovskite absorption layer obtained in step (3) of Example 2 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0194] Example 3

[0195] A solar cell was prepared according to the method of Example 1, except that:

[0196] In step (3), 0.024 mol of phosphatidylcholine is replaced with 0.024 mol of potassium chloride ammonium.

[0197] The perovskite absorption layer obtained in step (3) of Example 3 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0198] Example 4

[0199] A solar cell was prepared according to the method of Example 1, except that:

[0200] In step (3), 0.0048 mol of thiosemicarbazide was replaced by 0.0048 mol of acetylthiourea.

[0201] The perovskite absorption layer obtained in step (3) of Example 4 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0202] Example 5

[0203] A solar cell was prepared according to the method of Example 1, except that:

[0204] In step (3), 0.0048 mol of thiosemicarbazide is replaced by 0.0048 mol of 3-aminopropanesulfonic acid.

[0205] The perovskite absorption layer obtained in step (3) of Example 5 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0206] Example 6

[0207] A solar cell was prepared according to the method of Example 1, except that:

[0208] In step (3), the amount of phosphatidylcholine added was adjusted to 0.012 mol.

[0209] The perovskite absorption layer obtained in step (3) of Example 6 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0210] Example 7

[0211] A solar cell was prepared according to the method of Example 1, except that:

[0212] In step (3), the amount of phosphatidylcholine added was adjusted to 0.06 mol.

[0213] The perovskite absorption layer obtained in step (3) of Example 7 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0214] Example 8

[0215] A solar cell was prepared according to the method of Example 1, except that:

[0216] In step (3), the amount of thiosemicarbazide added was adjusted to 0.0024 mol.

[0217] The perovskite absorption layer obtained in step (3) of Example 8 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0218] Example 9

[0219] A solar cell was prepared according to the method of Example 1, except that:

[0220] In step (3), the amount of thiosemicarbazide added was adjusted to 0.006 mol.

[0221] The perovskite absorption layer obtained in step (3) of Example 9 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0222] Comparative Example 1

[0223] A solar cell was prepared according to the method of Example 1, except that:

[0224] In step (3), phosphatidylcholine and thiosemicarbazide are not added during the preparation of the perovskite precursor solution.

[0225] The perovskite absorption layer obtained in step (3) of Comparative Example 1 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0226] Comparative Example 2

[0227] A solar cell was prepared according to the method of Example 1, except that:

[0228] No thiosemicarbazide (TSC) was added during the preparation of the perovskite precursor solution.

[0229] The perovskite absorption layer obtained in step (3) of Comparative Example 2 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0230] Comparative Example 3

[0231] A solar cell was prepared according to the method of Example 1, except that:

[0232] No phosphatidylcholine (LP) is added during the preparation of the perovskite precursor solution.

[0233] The perovskite absorption layer obtained in step (3) of Comparative Example 3 was tested using a method similar to that of Example 1. The test results are shown in Table 1-1 below.

[0234] Table 1-1

[0235] In Table 1-1, “ / ” indicates that it is not added.

[0236] Testing of solar cell optical performance

[0237] (1) Photoelectric performance test (photoelectric conversion efficiency (PCE), open circuit voltage (Voc), short circuit current (Jsc))

[0238] Using AM1.5G standard light source as the simulated light source, a four-channel digital source meter (Keithley 2400SMU) was used to measure the photoelectric performance parameters of the battery under the light source to obtain the volt-ampere characteristic curve. Test conditions: total irradiance 100mW / cm 2 The battery temperature under test is 25℃ and the spectral distribution is AM1.5G.

[0239] According to the volt-ampere characteristic curve, we can get P out 、P in 、V mpp 、J mpp 、V oc 、J sc , then, the PCE is calculated based on the following formula:

[0240] PCE=P out / P in

[0241] =V oc ×J sc ×(V mpp ×J mpp ) / (V oc ×J sc );

[0242] =V oc ×J sc ×FF;

[0243] Among them, P in 、P out 、V mpp 、J mpp 、V oc 、J sc, FF represent: incident light power, working output power of the tested battery, voltage at the maximum power point of the tested battery, current at the maximum power point of the tested battery, open circuit voltage, short circuit current, and fill factor, respectively.

[0244] (2) Stability test

[0245] The battery to be tested was stored at 25° C. for one month. The PCE of the battery to be tested after storage was measured using the test conditions for the photoelectric performance described in (1).

[0246] The percentage of the PCE obtained after one month of storage relative to the PCE measured in (1) above is taken as the retention rate of the tested battery.

[0247] The solar cells obtained in Examples 1-9 and Comparative Examples 1 to 3 were tested under the above test conditions. The test results are shown in Tables 1-2 below.

[0248] Table 1-2

[0249] The data in Tables 1-1 and 1-2 show that compared to the calcium solar cells of Comparative Examples 1 to 3, the solar cells prepared in Examples 1 to 9 of the present disclosure have perovskite grains with a grain size of 1 μm to 3 μm accounting for greater than or equal to 90%, and perovskite grains with a grain size of 2 μm ± 0.2 μm accounting for greater than or equal to 50%. The solar cells of Examples 1 to 9 have improved stability and photoelectric performance.

[0250] It should be noted that the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and within the scope of the technical solution of the present disclosure, embodiments having substantially the same structure as the technical concept and exerting the same effects are all included in the technical scope of the present disclosure. In addition, within the scope of the present disclosure, various modifications that can be imagined by those skilled in the art to the embodiments, and other methods constructed by combining some of the constituent elements of the embodiments are also included in the scope of the present disclosure.

Claims

1. A solar cell comprising a perovskite light-absorbing layer; The perovskite light absorption layer includes perovskite grains, and among the perovskite grains, the number of perovskite grains with a grain size of 1 μm to 3 μm accounts for greater than or equal to 90%.

2. The solar cell according to claim 1, wherein The number of perovskite grains with a grain size of 2 μm±0.2 μm accounts for greater than or equal to 40%.

3. The solar cell according to claim 1 or 2, wherein The number of perovskite grains with a grain size of 2 μm±0.2 μm accounts for greater than or equal to 50%.

4. The solar cell according to any one of claims 1 to 3, wherein The roughness of the perovskite light absorbing layer is 30nm-70nm.

5. The solar cell according to any one of claims 1 to 4, wherein The thickness uniformity of the perovskite light absorbing layer is less than 5%, wherein the thickness uniformity is calculated by the following formula: (maximum value - minimum value) / (maximum value + minimum value) The maximum value and the minimum value refer to the maximum thickness value and the minimum thickness value of the perovskite light absorbing layer, respectively.

6. The solar cell according to any one of claims 1 to 5, wherein At least some of the perovskite grains with a grain size of 1 μm to 3 μm penetrate the perovskite light absorbing layer in the thickness direction of the perovskite light absorbing layer.

7. The solar cell according to any one of claims 1 to 6, wherein The perovskite grains include one of the compound represented by formula (I) and the compound represented by formula (II): [A][B][X]3 (I); [A]2[C][D][X]6 (II); Wherein, A comprises at least one of an inorganic monovalent cation and an organic monovalent cation; B includes inorganic divalent cations; C includes inorganic monovalent cations; D includes inorganic trivalent cations; X includes an anion.

8. The solar cell according to claim 7, wherein The A includes (NR1R2R3R4) + 、(R1R2N=CR3R4) + 、(R1R2N-C(R5)=NR3R4) + 、(R1R2N-C(NR5R6)=NR3R4) + 、Li + 、Na + , K + , Rb + 、Cs + , wherein R1, R2, R3, R4, R5 and R6 are each independently selected from H, substituted or unsubstituted C1-C20 alkyl or substituted or unsubstituted aromatic group; The B includes Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Pd 2+ 、Yb 2+ 、Eu 2+ At least one of; The C includes Li + 、Na + , K + , Rb + 、Cs + 、Cu + 、Ag + 、Au + 、Hg + At least one of; The D includes Bi 3+ 、Sb 3+ Cr 3+ 、Fe 3+ 、Co 3+ 、Ga 3+ 、As 3+ 、Ru 3+ , Rh 3+ 、In 3+ 、Ir 3+ 、Au 3+ 、Al 3+ At least one of; The X includes F - 、Cl - Br - , I - 、SCN - 、CNO - 、OCN - 、OSCN - SH - OH - 、CN - 、SeCN - At least one of .

9. The solar cell according to any one of claims 1 to 8, wherein The solar cell further includes a first electrode disposed on one side of the perovskite light absorption layer, a second electrode disposed on the other side of the perovskite light absorption layer, a first carrier transport layer disposed between the first electrode and the perovskite light absorption layer; and a second carrier transport layer disposed between the perovskite light absorption layer and the second electrode; The first carrier transport layer is an electron transport layer or a hole transport layer; the second carrier transport layer is an electron transport layer or a hole transport layer, but is different from the first carrier transport layer.

10. A perovskite precursor solution, comprising a solvent, a perovskite precursor raw material, a viscosity modifier, and a complexing agent; The complexing agent includes at least one of thiosemicarbazide, acetylthiourea, 3-aminopropanesulfonic acid, benzylthiamine, and benzenesulfonylacetic acid; The viscosity modifier includes at least one of phosphatidylcholine, phosphatidylethanolamine, phosphatidic acid, serine phospholipid, potassium chloride ammonium, lead thiocyanate, and urea.

11. The perovskite precursor solution according to claim 10, wherein Based on the molar amount of the target cation in the perovskite precursor raw material, the molar percentage of the complexing agent is 0.1%-1%; The perovskite crystals formed by the perovskite precursor solution include one of the compound represented by formula (I) and the compound represented by formula (II): [A][B][X]3 (I); [A]2[C][D][X]6 (II); Wherein, A comprises at least one of an inorganic monovalent cation and an organic monovalent cation; B includes inorganic divalent cations; C includes inorganic monovalent cations; D includes inorganic trivalent cations; X includes anions, The target cation is an inorganic divalent cation at the B position or the target cation is an inorganic trivalent cation at the C position.

12. The perovskite precursor solution according to claim 11, wherein The A includes (NR1R2R3R4) + 、(R1R2N=CR3R4) + 、(R1R2N-C(R5)=NR3R4) + 、(R1R2N-C(NR5R6)=NR3R4) + 、Li + 、Na + , K + , Rb + 、Cs + , wherein R1, R2, R3, R4, R5 and R6 are each independently selected from H, substituted or unsubstituted C1-C20 alkyl or substituted or unsubstituted aromatic group; The B includes Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Pd 2+ 、Yb 2+ 、Eu 2+ At least one of; The C includes Li + 、Na + , K + , Rb + 、Cs + 、Cu + 、Ag + 、Au + 、Hg + At least one of; The D includes Bi 3+ 、Sb 3+ Cr 3+ 、Fe 3+ 、Co 3+ 、Ga 3+ 、As 3+ 、Ru 3+ , Rh 3+ 、In 3+ 、Ir 3+ 、Au 3+ 、Al 3+ At least one of; The X includes F - 、Cl - Br - , I - 、SCN - 、CNO - 、OCN - 、OSCN - SH - OH - 、CN - 、SeCN - At least one of .

13. The perovskite precursor solution according to claim 11 or 12, wherein: Based on the molar amount of the target cation, the mole percentage of the complexing agent is 0.2%-0.6%.

14. The perovskite precursor solution according to any one of claims 11 to 13, wherein Based on the molar amount of the target cation in the perovskite precursor raw material, the molar percentage of the viscosity modifier is 1%-5%.

15. The perovskite precursor solution according to claim 14, wherein The mole percentage of the viscosity modifier is 1.5% to 3.5% based on the molar amount of the target cation.

16. The perovskite precursor solution according to any one of claims 11 to 15, wherein The solvent includes at least one of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

17. A method for preparing a solar cell, the method comprising forming a perovskite light-absorbing layer, wherein: The forming of the perovskite light absorbing layer comprises the following steps: Providing a perovskite precursor solution according to any one of claims 10 to 16; coating the perovskite precursor solution on a substrate to form a perovskite precursor wet film, performing vacuum flash evaporation on the perovskite precursor wet film, and Heat treatment is performed to obtain a perovskite light-absorbing layer.

18. The preparation method according to claim 17, wherein The heat treatment is performed at a temperature of 100° C. to 230° C. for 10 minutes to 60 minutes.

19. A photovoltaic module, comprising the solar cell according to any one of claims 1 to 9 or the solar cell prepared by the preparation method according to claim 17 or 18.

20. A power generation device, comprising the solar cell according to any one of claims 1 to 9 or the solar cell prepared by the preparation method according to claim 17 or 18.

21. An electrical device, comprising the solar cell according to any one of claims 1 to 9 or the solar cell manufactured by the preparation method according to claim 17 or 18.

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