Perovskite light absorption layer and preparation method thereof, and perovskite solar cell

Abstract

The invention relates to the technical field of solar cells, and mainly provides a perovskite light absorption layer and a preparation method thereof, and a perovskite solar cell. The preparation method of the perovskite light absorption layer comprises the following steps: preparing a substrate and a perovskite precursor solution; the substrate is placed on a spin coater, and a laser is arranged above the substrate; after the perovskite precursor solution is dropwise added to the substrate, a spin coater and a laser are started, spin coating and laser annealing are carried out on the perovskite precursor solution at the same time, and a perovskite light absorption layer is formed. According to the preparation method of the perovskite light absorption layer in the technical scheme, the crystallization quality and the preparation efficiency of the perovskite light absorption layer can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite light-absorbing layer and a preparation method thereof, and a perovskite solar cell. Background Art

[0002] Perovskite is a material with a unique crystal structure and excellent optoelectronic properties. It is widely used in solar cells, LEDs and other fields. At present, in the preparation process of the perovskite light-absorbing layer, the perovskite precursor solution is first applied to form a perovskite film, and then the perovskite film is annealed to form a perovskite light-absorbing layer. This method has a relatively low production efficiency. In addition, heat treatment is a key link that will directly affect the crystallization quality and device performance of the perovskite light-absorbing layer. Commonly used heat treatment methods such as furnace annealing and solvent annealing often take a long time, and it is difficult to accurately control parameters such as temperature and heating time, resulting in unstable performance of perovskite.

[0003] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0004] The present application provides a perovskite light absorbing layer and a preparation method thereof, and a perovskite solar cell to solve or alleviate the above-mentioned technical problems. The preparation method of the perovskite light absorbing layer in the technical solution of the present application can improve the crystallization quality and preparation efficiency of the perovskite light absorbing layer.

[0005] In a first aspect, an embodiment of the present application provides a method for preparing a perovskite light absorbing layer, comprising: preparing substrates and perovskite precursor solutions; placing the substrate on a spin coater and arranging a laser above the substrate; After the perovskite precursor solution is dripped onto the substrate, a spin coater and a laser are turned on, and the perovskite precursor solution is spin-coated and laser annealed simultaneously to form a perovskite light-absorbing layer.

[0006] Optionally, laser annealing is performed on the perovskite precursor solution, comprising: The laser emits a fan-shaped light spot, and the perovskite precursor solution is baked by using the fan-shaped light spot; wherein the center of the fan-shaped light spot is located at the center of the circumscribed circle of the substrate, and the diameter of the fan-shaped light spot is greater than or equal to the diameter of the circumscribed circle of the substrate; or The laser is made to emit a circular spot, and the circular spot is used to perform linear reciprocating scanning on the perovskite precursor solution; wherein, the scanning starting point of the circular spot is the center of the circumscribed circle of the substrate, the maximum scanning path length of the circular spot is greater than or equal to the radius of the circumscribed circle of the substrate, and the farther the circular spot is from the center of the circumscribed circle of the substrate, the slower the scanning speed.

[0007] Optionally, the fan-shaped light spot is a single fan-shaped light spot or a plurality of fan-shaped light spots.

[0008] Optionally, the central angle of the fan-shaped light spot is 1-360°.

[0009] Optionally, the diameter of the circular light spot is 1-5 mm.

[0010] Optionally, the scanning speed formula of the circular spot is: 2πv0 / v=(x1+v1 2 / 2a) / (x+v1 2 / 2a); Among them, v represents the scanning speed of the dot light spot, v0 represents the scanning speed of the starting point of the dot light spot, v1 represents the scanning speed of the end point of the dot light spot, a represents the scanning acceleration of the dot light spot, x represents the distance from the dot light spot to the center of the circumscribed circle of the substrate, that is, the scanning path length of the dot light spot, and x1 represents the distance from the end point of the dot light spot to the center of the circumscribed circle of the substrate, that is, the maximum scanning path length of the dot light spot.

[0011] Optionally, the output light of the laser is flat-top light, the wavelength of the laser is 266-1064 nm, the power of the laser is 1-50 W, and the pulse width of the laser is 1-50 ns.

[0012] Optionally, the frequency of the laser is 100-2000 Hz, and the rotation speed of the spin coater is 2000-4000 rpm.

[0013] Optionally, the spin coating time of the spin coater is 20-40s, and the laser annealing time is the same as the spin coating time of the spin coater.

[0014] Optionally, the particle size of the perovskite light absorbing layer is 300-1000nm.

[0015] In a second aspect, an embodiment of the present application provides a perovskite light absorbing layer, which is prepared using any of the above-mentioned methods for preparing a perovskite light absorbing layer.

[0016] In a third aspect, an embodiment of the present application provides a perovskite solar cell, comprising: a conductive substrate, a first transmission layer, a perovskite light absorption layer, a second transmission layer, and an electrode stacked in sequence; Wherein, the perovskite light absorbing layer is prepared by using any of the above-mentioned methods for preparing a perovskite light absorbing layer.

[0017] The above technical solution adopted in the embodiment of the present application may have the following advantages: Laser annealing is performed while spin coating the perovskite precursor solution, so that the perovskite precursor solution crystallizes while forming a film, so as to achieve a uniform annealing effect, reduce crystal defects, and effectively improve the crystallization quality of the perovskite light-absorbing layer; and the laser has a high energy density and precise controllability, which can achieve rapid heating and cooling of the perovskite in a short time, thereby shortening the annealing time, and can accurately control the temperature and heating time, thereby improving the crystallization quality and preparation efficiency of the perovskite light-absorbing layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0019] Figure 1 is a flow chart of a method for preparing a perovskite light-absorbing layer according to an embodiment of the present application; Figure 2 It is a schematic diagram of the structure of a perovskite solar cell according to an embodiment of the present application.

[0020] Description of reference numerals: 10. Conductive substrate; 20. First transmission layer; 30. Perovskite light absorption layer; 40. Second transmission layer; 50. Electrode. DETAILED DESCRIPTION

[0021] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0022] like Figure 1 As shown, the embodiment of the present application provides a method for preparing a perovskite light absorbing layer, comprising: S100: preparing substrate and perovskite precursor solution; S200: placing the substrate on a spin coater and setting a laser above the substrate; S300: After the perovskite precursor solution is dropped onto the substrate, a spin coater and a laser are turned on, and the perovskite precursor solution is spin-coated and laser annealed at the same time to form a perovskite light absorbing layer.

[0023] Laser annealing is performed while spin coating the perovskite precursor solution, so that the perovskite precursor solution crystallizes while forming a film, so as to achieve a uniform annealing effect, reduce crystal defects, and effectively improve the crystallization quality of the perovskite light-absorbing layer; and the laser has a high energy density and precise controllability, which can achieve rapid heating and cooling of the perovskite in a short time, thereby shortening the annealing time, and can accurately control the temperature and heating time, thereby improving the crystallization quality and preparation efficiency of the perovskite light-absorbing layer.

[0024] In step S100, preparing a substrate includes: providing a conductive substrate; A first transmission layer is formed on a conductive substrate.

[0025] Before forming the first transmission layer on the conductive substrate, the conductive substrate may be cleaned, laser etched, and ultraviolet treated. The step of cleaning the conductive substrate may include: placing the conductive substrate in an ultrasonic cleaning instrument, and ultrasonically cleaning it with deionized water, isopropyl alcohol, and ethanol, respectively, and the cleaning time of each step is 20-40 minutes. The step of ultraviolet treating the conductive substrate may include: treating the conductive substrate with a UV-zone, wherein the treatment time is 20-40 minutes.

[0026] In step S100, the perovskite precursor solution includes a perovskite material and an organic solvent; wherein the perovskite material includes one or more of methylamine lead iodide (CH3NH3PbI3) and formamidine lead iodide (CH2(NH2)2PbI3); the organic solvent includes one or more of N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), diphenyl sulfoxide (DPSO), dimethylformamide (DMF), acetonitrile (ACN), 2-methoxyethanol (2-ME), dimethylacetamide (DMAc), N,N'-dimethylpropylene urea (DMPU), and 1,4-butyrolactone.

[0027] In step S200, the substrate is placed on a spin coater, wherein the conductive substrate is located at the bottom and the first transmission layer is located at the top.

[0028] In step S300, the spin coater and the laser may be turned on at the same time, or the laser may be turned on first and then the spin coater. In short, it is ensured that laser annealing is performed while the perovskite solution is spin-coated.

[0029] In step S300, after the perovskite light absorbing layer is formed, the spin coater and the laser are turned off simultaneously to ensure that the spin coating and laser annealing are performed simultaneously.

[0030] In some embodiments, in step S300, laser annealing is performed on the perovskite precursor solution, including: The laser emits a fan-shaped spot, and the fan-shaped spot is used to bake the perovskite precursor solution; wherein the center of the fan-shaped spot is located at the center of the circumscribed circle of the substrate, and the diameter of the fan-shaped spot is greater than or equal to the diameter of the circumscribed circle of the substrate.

[0031] In an embodiment of the present application, a fan-shaped light spot is used to bake the perovskite precursor solution, and the center of the fan-shaped light spot is located at the center of the circumscribed circle of the substrate. The intensity of the light spot is equal everywhere, which can ensure uniform coverage of the light spot. After the perovskite precursor solution is spin-coated, the entire surface can be uniformly irradiated by the laser, which helps to uniformly heat and anneal the perovskite precursor solution, thereby improving the uniformity of the perovskite light absorption layer.

[0032] In some embodiments, the fan-shaped light spot is a single fan-shaped light spot or a multi-fan-shaped light spot. When the fan-shaped light spot is a single fan-shaped light spot or a multi-fan-shaped light spot, the annealing can be made more uniform. The multi-fan-shaped light spot refers to a combination of multiple (for example, 2, 3, 4 or 5) single fan-shaped light spots, wherein the multiple single fan-shaped light spots can be spaced apart from each other or combined into a whole.

[0033] In some embodiments, the central angle of the fan-shaped spot is 1-360°. In other embodiments, the central angle of the fan-shaped spot is 5-90°; preferably, the central angle of the fan-shaped spot is 10-60°; more preferably, the central angle of the fan-shaped spot is 15-30°. When the central angle of the fan-shaped spot is smaller, the energy provided by the fan-shaped laser is smaller, making the annealing more uniform; but the circular angle of the fan-shaped spot cannot be too small, otherwise it will increase the annealing time. When the fan-shaped spot is formed by combining multiple single fan-shaped spots (i.e., multi-fan-shaped spots), the central angle of the fan-shaped spot refers to the sum of the central angles of the multiple single fan-shaped spots. Specifically, the central angle of the fan-shaped spot can be 10°, 15°, 20°, 25°, 30°, 40°, 50° or 60°.

[0034] In some embodiments, in step S300, laser annealing is performed on the perovskite precursor solution, including: The laser emits a circular spot, and the circular spot is used to perform linear reciprocating scanning on the perovskite precursor solution; wherein, the scanning starting point of the circular spot is the center of the circumscribed circle of the substrate, and the maximum scanning path length of the circular spot is greater than or equal to the radius of the circumscribed circle of the substrate. The farther the circular spot is from the center of the circumscribed circle of the substrate, the slower the scanning speed.

[0035] In the embodiment of the present application, when the perovskite precursor solution is spin-coated using a spin coater, the closer to the center of the circumscribed circle of the substrate, the smaller the area radius, and the farther away from the center of the circumscribed circle of the substrate, the larger the area radius. Since the dot light spot moves in a straight line from the center of the circumscribed circle of the substrate as an end point (i.e., the starting point) to the end point of the origin light spot (equivalent to moving along the radius route), when the dot light spot moves the same distance, the farther away from the center of the circumscribed circle of the substrate, the larger the area to be scanned, so the scanning speed should be reduced so that more heat is absorbed by the perovskite precursor solution in the area, so that the energy obtained by the entire perovskite precursor solution is uniform, thereby improving the uniformity of the perovskite light absorption layer. The maximum scanning path length of the dot light spot is the distance between the end point of the dot light spot and the center of the circumscribed circle of the substrate. The dot light spot makes a straight reciprocating motion between the starting point of the dot light spot and the end point of the dot light spot. The closer to the starting point of the dot light spot, the faster the scanning speed of the dot light spot is, and the closer to the end point of the dot light spot, the slower the scanning speed of the dot light spot is, but it cannot be 0.

[0036] In some embodiments, the diameter of the circular spot is 1-5 mm.

[0037] When the diameter of the dot light spot is 1-5 mm, the dot light spot with a smaller diameter can accurately locally heat the perovskite precursor solution, which helps to control the crystallization process; and helps to adjust the scanning speed to achieve uniform annealing, thereby improving the uniformity of the perovskite light absorption layer. Specifically, the diameter of the dot light spot can be 1 mm, 2 mm, 3 mm, 4 mm or 5 mm.

[0038] In some embodiments, the scanning speed formula of the dot light spot is: 2πv0 / v=(x1+v1 2 / 2a) / (x+v1 2 / 2a); Among them, v represents the scanning speed of the dot light spot, v0 represents the scanning speed of the starting point of the dot light spot, v1 represents the scanning speed of the end point of the dot light spot, a represents the scanning acceleration of the dot light spot, x represents the distance from the dot light spot to the center of the circumscribed circle of the substrate, that is, the scanning path length of the dot light spot, and x1 represents the distance from the end point of the dot light spot to the center of the circumscribed circle of the substrate, that is, the maximum scanning path length of the dot light spot.

[0039] When the spot light spot scans to the center of the circumscribed circle of the substrate, the scanning path length of the spot light spot can be recorded as x0, x0 is 0, and the scanning speed is v0 (v0 is not equal to 0), which is the scanning speed of the starting point of the spot light spot. When the spot light spot scans to the edge of the circumscribed circle of the substrate, the scanning path length x of the spot light spot is the radius of the circumscribed circle of the substrate.

[0040] In some embodiments, the output light of the laser is flat-top light, the wavelength of the laser is 266-1064 nm, the power of the laser is 1-50 W, and the pulse width of the laser is 1-50 ns.

[0041] When the wavelength of the laser is 266-1064nm, the emitted laser has good penetration and can be effectively absorbed by the perovskite film to generate heat, thereby achieving the effect of heating annealing. Specifically, the wavelength of the laser can be 266nm, 355nm, 457nm, 532nm, 808nm, 915nm or 1064nm.

[0042] When the power of the laser is 1-50W, sufficient energy can be provided for effective annealing treatment, and the difficulty in controlling the crystallinity due to excessive energy can be avoided, which helps to accurately control the annealing process. Specifically, the power of the laser can be 1W, 3W, 5W, 8W, 10W, 20W, 30W, 40W or 50W.

[0043] When the pulse width of the laser is 1-50ns, it is a nanosecond pulse, which can transfer a large amount of energy to the perovskite film in a very short time, promote rapid heating of the material, and help form a finer and more uniform grain structure, thereby improving the performance of the perovskite light-absorbing layer. Specifically, the pulse width of the laser can be 1ns, 5ns, 10ns, 20ns, 30ns, 40ns or 50ns. The flat-top beam can provide uniform energy distribution, which can ensure consistent energy across the entire perovskite film area and avoid local overheating or uneven heat.

[0044] In some embodiments, the frequency of the laser is 100-2000 Hz, and the rotation speed of the spin coater is 2000-4000 rpm.

[0045] When the frequency of the laser is 100-2000 Hz, continuous heat treatment can be provided, which not only helps to quickly complete the annealing process of a large area, but also improves the processing efficiency. Specifically, the frequency of the laser can be 100 Hz, 300 Hz, 500 Hz, 700 Hz, 1000 Hz, 1200 Hz, 1300 Hz, 1500 Hz, 1600 Hz, 1800 Hz or 2000 Hz.

[0046] When the rotation speed of the spin coater is controlled to 2000-4000 rpm, the rotation speed and the frequency of the laser are relatively matched, further improving the uniformity and density of the perovskite light absorbing layer, thereby improving the quality of the perovskite light absorbing layer. Specifically, the rotation speed of the spin coater can be 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm or 4000 rpm.

[0047] In some embodiments, the spin coating time of the spin coater is 20-40 seconds, and the laser annealing time is the same as the spin coating time of the spin coater.

[0048] The spin coating time of the spin coater is the same as the laser annealing time, so that the spin coating and laser annealing are performed simultaneously, which helps to improve the uniformity of the perovskite light absorbing layer. And the thickness of the perovskite light absorbing layer can be more accurately controlled. Specifically, the spin coating time of the spin coater can be 20s, 25s, 30s, 35s or 40s.

[0049] In some embodiments, when performing spin coating and laser annealing, the ambient temperature is 25° C., the ambient atmosphere is a nitrogen atmosphere, and the ambient pressure is a standard atmospheric pressure.

[0050] In some embodiments, the particle size of the perovskite light absorbing layer is 300-1000 nm.

[0051] When the particle size of the perovskite light absorbing layer is 300-1000 nm, the thickness of the perovskite light absorbing layer is more uniform. Specifically, the particle size of the perovskite light absorbing layer can be 300 nm, 500 nm, 700 nm, 800 nm or 1000 nm.

[0052] An embodiment of the present application provides a perovskite light absorbing layer, which is prepared by the preparation method of the perovskite light absorbing layer of any of the above embodiments.

[0053] like Figure 2 As shown, the embodiment of the present application provides a perovskite solar cell, comprising: a conductive substrate 10, a first transmission layer 20, a perovskite light absorption layer 30, a second transmission layer 40, and an electrode 50 stacked in sequence; The perovskite light absorbing layer 30 is prepared by using the preparation method of the perovskite light absorbing layer of any of the above embodiments.

[0054] In an embodiment of the present application, the first transport layer is an electron transport layer, and the second transport layer is a hole transport layer; or, the first transport layer is a hole transport layer, and the second transport layer is an electron transport layer.

[0055] In an alternative embodiment, the conductive substrate may be a transparent conductive glass, for example, fluorine-doped tin oxide (FTO) glass, indium tin oxide (ITO) glass, indium zinc oxide (IZO) glass, tungsten-doped indium oxide (IWO) glass, or aluminum-doped zinc oxide (AZO) glass.

[0056] In an optional embodiment, the material of the hole transport layer includes but is not limited to [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), benzoic acid, 4-[bis(2,4-dimethoxybiphenyl-4-yl)amino]-biphenyl-4-carboxylic acid [MC-43], 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Sprio-OMeTAD), poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine) (PTAA), polymer of 3-hexylthiophene (P3HT), poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDO T:PSS), 2,2',7,7'-tetrakis(di-p-tolylamino)spiro-9,9'-difluorene (Spiro-TTB), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanodimethyl-p-benzoquinone (F4-TCNQ), 2,2'-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6TCNNQ), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC), nickel oxide (NiO x ), tin dioxide (SnO2), cuprous thiocyanate (CuSCN), copper aluminate (CuAlO2), vanadium pentoxide (V2O5), cadmium sulfide (CdS), and cadmium selenide (CdSe).

[0057] In some embodiments, the thickness of the perovskite light absorbing layer may be 300-800 nm.

[0058] In an optional embodiment, the material of the electron transport layer includes but is not limited to TiO2, SnO2, ZnO, ZrO2, gallium zinc oxide (GZO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), indium tin oxide (ITO), BaSnO3, TiSnO x SnZnO x , fullerene, fullerene derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) or more.

[0059] In an optional embodiment, the material of the electrode includes but is not limited to one or more of Au, Ag, Al, Cu, transparent conductive oxide (TCO), graphene, and nanocrystalline silicon.

[0060] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0061] Example A1 The method for preparing the perovskite light absorbing layer of embodiment A1 comprises: S110: preparing substrate and perovskite precursor solution; S210: placing the substrate on a spin coater and arranging a laser above the substrate; S310: After the perovskite precursor solution is dropped onto the substrate, a spin coater and a laser are turned on, and the laser emits a fan-shaped spot. While the perovskite precursor solution is spin-coated, the perovskite precursor solution is baked by using the fan-shaped spot to achieve laser annealing to form a perovskite light absorption layer; The center of the fan-shaped light spot is located at the center of the circumscribed circle of the substrate, the diameter of the fan-shaped light spot is equal to the diameter of the circumscribed circle of the substrate, the central angle of the fan-shaped light spot is 60°, and the fan-shaped light spot is a multi-fan-shaped light spot formed by combining two single fan-shaped light spots (both with central angles of 30°); The wavelength of the laser is 532 nm, the power of the laser is 10 W, the pulse width of the laser is 10 ns, the output light of the laser is flat-top light, the frequency of the laser is 1 kHz, the rotation speed of the spin coater is 3000 rpm, the spin coating time of the spin coater is 30 s, and the laser annealing time is the same as the spin coating time of the spin coater.

[0062] Example A2 The method for preparing the perovskite light absorbing layer of embodiment A2 comprises: S120: preparing substrate and perovskite precursor solution; S220: placing the substrate on a spin coater and setting a laser above the substrate; S320: After the perovskite precursor solution is dripped onto the substrate, a spin coater and a laser are turned on, and the laser emits a circular spot light, and while the perovskite precursor solution is spin-coated, the circular spot light is used to perform a linear reciprocating scan on the perovskite precursor solution to achieve laser annealing and form a perovskite light absorption layer; The scanning starting point of the circular spot is the center of the circumscribed circle of the substrate, the maximum scanning path length of the circular spot is equal to the radius of the circumscribed circle of the substrate, and the diameter of the circular spot is 3 mm. The scanning speed formula of the circular spot is: 2πv0 / v=(x1+v1 2 / 2a) / (x+v1 2 / 2a); v represents the scanning speed of the dot light spot, v0 represents the scanning speed of the starting point of the dot light spot, v1 represents the scanning speed of the end point of the dot light spot, a represents the scanning acceleration of the dot light spot, x represents the distance between the dot light spot and the center of the circumscribed circle of the substrate, that is, the scanning path length of the dot light spot, and x1 represents the distance between the end point of the dot light spot and the center of the circumscribed circle of the substrate, that is, the maximum scanning path length of the dot light spot; The wavelength of the laser is 532 nm, the power of the laser is 10 W, the pulse width of the laser is 10 ns, the output light of the laser is flat-top light, the frequency of the laser is 1 kHz, the rotation speed of the spin coater is 3000 rpm, the spin coating time of the spin coater is 30 s, and the laser annealing time is the same as the spin coating time of the spin coater.

[0063] In order to more clearly illustrate the technical effects of the embodiments of the present application, the present application also points out a method for preparing the perovskite light-absorbing layer of comparative example A1.

[0064] Comparative Example A1 The method for preparing the perovskite light absorbing layer of Comparative Example A1 comprises: S130: preparing substrate and perovskite precursor solution; S230: placing the substrate on a spin coater, dropping a perovskite precursor solution onto the substrate, turning on the spin coater, and spin coating the perovskite precursor solution to form a perovskite film; S330: Using a laser, laser annealing is performed on the perovskite film to form a perovskite light absorbing layer.

[0065] Among them, the wavelength of the laser is 532nm, the power of the laser is 10W, the pulse width of the laser is 10ns, the output light of the laser is flat-top light, the spot size of the laser is 1mm*100mm, the frequency of the laser is 1kHz, the rotation speed of the spin coater is 3000 rpm, the spin coating time of the spin coater is 30s, and the laser annealing time is the same as the spin coating time of the spin coater.

[0066] In addition, the present application also provides perovskite solar cells of Examples B1-B2 and Comparative Example B1. The perovskite solar cells of Examples B1-B2 and Comparative Example B1 all include: a conductive substrate, a first transmission layer, a perovskite light absorption layer, a second transmission layer, and an electrode stacked in sequence, except that the perovskite light absorption layer in Examples B1-B2 and Comparative Example B1 is prepared by the preparation method of the perovskite light absorption layer in Examples A1-A2 and Comparative Example A1, respectively.

[0067] The present application also prepares the perovskite solar cells of Examples B1-B2 and Comparative Example B1 into corresponding photovoltaic modules, and performs performance tests on the corresponding photovoltaic modules to obtain their short-circuit current density Jsc, open-circuit voltage Voc, fill factor FF, and conversion efficiency Eff. The relevant test results are shown in Table 1.

[0068] Table 1

[0069] It can be seen from the data in Table 1 that, compared with Comparative Example B1, the short-circuit current density and open-circuit voltage of the photovoltaic module made of the perovskite solar cells in Examples B1 to B2 of the present application are slightly improved, and the fill factor and conversion efficiency are significantly improved. This shows that the embodiments of the present application perform laser annealing while spin-coating the perovskite precursor solution, which can improve the crystallization quality of the perovskite light-absorbing layer and make the corresponding solar cell have good electrical properties.

[0070] In summary, in the embodiments of the present application, laser annealing is performed while spin coating the perovskite precursor solution, so that the perovskite precursor solution is crystallized while forming a film, so as to achieve a uniform annealing effect, reduce crystal defects, and effectively improve the crystallization quality of the perovskite light absorbing layer; and the laser has a high energy density and precise controllability, which can achieve rapid heating and cooling of the perovskite in a short time, thereby shortening the annealing time, and can accurately control the temperature and heating time, thereby improving the crystallization quality and preparation efficiency of the perovskite light absorbing layer.

[0071] It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0072] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0073] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0074] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0075] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a perovskite light-absorbing layer, characterized in that: include: preparing substrates and perovskite precursor solutions; placing the substrate on a spin coater and arranging a laser above the substrate; After the perovskite precursor solution is dripped onto the substrate, a spin coater and a laser are turned on, and the perovskite precursor solution is spin-coated and laser annealed simultaneously to form a perovskite light-absorbing layer.

2. The method for preparing a perovskite light absorbing layer according to claim 1, characterized in that: The perovskite precursor solution is subjected to laser annealing, comprising: The laser emits a fan-shaped light spot, and the perovskite precursor solution is baked by using the fan-shaped light spot; wherein the center of the fan-shaped light spot is located at the center of the circumscribed circle of the substrate, and the diameter of the fan-shaped light spot is greater than or equal to the diameter of the circumscribed circle of the substrate; or The laser is made to emit a circular spot, and the circular spot is used to perform linear reciprocating scanning on the perovskite precursor solution; wherein, the scanning starting point of the circular spot is the center of the circumscribed circle of the substrate, the maximum scanning path length of the circular spot is greater than or equal to the radius of the circumscribed circle of the substrate, and the farther the circular spot is from the center of the circumscribed circle of the substrate, the slower the scanning speed.

3. The method for preparing a perovskite light absorbing layer according to claim 2, characterized in that: The fan-shaped light spot is a single fan-shaped light spot or multiple fan-shaped light spots.

4. The method for preparing a perovskite light absorbing layer according to claim 2, characterized in that: The central angle of the fan-shaped light spot is 1-360°.

5. The method for preparing a perovskite light absorbing layer according to claim 2, characterized in that: The diameter of the circular spot is 1-5 mm.

6. The method for preparing a perovskite light absorbing layer according to claim 2, characterized in that: The scanning speed formula of the circular spot is: 2πv0 / v=(x1+v1 2 / 2a) / (x+v1 2 / 2a); Among them, v represents the scanning speed of the dot light spot, v0 represents the scanning speed of the starting point of the dot light spot, v1 represents the scanning speed of the end point of the dot light spot, a represents the scanning acceleration of the dot light spot, x represents the distance from the dot light spot to the center of the circumscribed circle of the substrate, that is, the scanning path length of the dot light spot, and x1 represents the distance from the end point of the dot light spot to the center of the circumscribed circle of the substrate, that is, the maximum scanning path length of the dot light spot.

7. The method for preparing a perovskite light absorbing layer according to any one of claims 1 to 6, characterized in that: The output light of the laser is flat-top light, the wavelength of the laser is 266-1064 nm, the power of the laser is 1-50 W, and the pulse width of the laser is 1-50 ns.

8. The method for preparing a perovskite light absorbing layer according to any one of claims 1 to 6, characterized in that: The frequency of the laser is 100-2000 Hz, and the rotation speed of the spin coater is 2000-4000 rpm.

9. The method for preparing a perovskite light absorbing layer according to any one of claims 1 to 6, characterized in that: The spin coating time of the spin coater is 20-40s, and the laser annealing time is the same as the spin coating time of the spin coater.

10. The method for preparing a perovskite light absorbing layer according to any one of claims 1 to 6, characterized in that: The particle size of the perovskite light-absorbing layer is 300-1000nm.

11. A perovskite light absorbing layer, characterized in that: The perovskite light-absorbing layer is prepared by the preparation method of any one of claims 1 to 10.

12. A perovskite solar cell, characterized in that: include: A conductive substrate, a first transmission layer, a perovskite light absorbing layer, a second transmission layer, and an electrode stacked in sequence; Wherein, the perovskite light absorbing layer is prepared by the preparation method of the perovskite light absorbing layer according to any one of claims 1 to 10.

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