A perovskite film on a large-size suede substrate, a preparation method thereof, and a battery

Abstract

The present invention relates to a perovskite film on a large-sized velvet substrate, a preparation method thereof, and a battery, belonging to the technical field of solar cells, and is used to solve at least one of the problems of the prior art in ultrasonic spraying, namely, that the perovskite film is not easy to grow in a conformal manner on a large-sized velvet surface, that the perovskite crystallinity is poor, that the solution utilization rate is low, and that the repeatability is poor. The method of the present invention fully atomizes the perovskite precursor solution under high pressure to form a Taylor cone and produce a Coulomb explosion, and during the flight, the increase in the charge-to-mass ratio of the colloid particles and the combined effect of the liquid tension cause the droplets to split multiple times, forming smaller droplets with a higher degree of atomization. At the same time, the generated electric field causes electrostatic attraction between the perovskite droplets and the substrate, and the charged droplets are targeted for deposition on the conductive substrate, which can better achieve conformal growth of grains along the velvet pyramid, thereby reducing solution loss, improving solution utilization, and making the perovskite crystallization quality higher and more repeatable.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a perovskite film on a large-sized suede substrate, a preparation method thereof, and a cell. Background Art

[0002] The bandgap adjustability and simple fabrication process of halide perovskite solar cells make them excellent candidates for tandem solar cells. The theoretical efficiency of perovskite / silicon tandem solar cells exceeds 42%, and the current record efficiency has reached 34.6%. The large-scale pyramid structures in crystalline silicon with large-scale velvet surfaces have excellent light trapping properties, resulting in higher light absorption and higher device short-circuit current density. Because the large-scale velvet pyramids are larger than 1 micron in size, conventional perovskite preparation methods such as spin coating, blade coating, and slit coating are unable to achieve conformal growth of perovskites on large-scale velvet surfaces (hereinafter referred to as large velvet surfaces). Evaporation methods for preparing perovskites require high vacuum levels, are costly, and cannot precisely control the composition ratios of the various precursors in the perovskite.

[0003] The current ultrasonic spraying method for preparing perovskite films relies solely on the atomization mechanism of the liquid surface being atomized by ultra-high-frequency acoustic vibrations. Atomization can only occur at the nozzle, without secondary atomization during flight. Furthermore, droplets tend to aggregate to form larger droplets during flight, further reducing their diameter. This results in a low degree of atomization, which can easily cause the perovskite solution to aggregate at the base of the pyramid, leading to non-conservative growth of the perovskite film. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a perovskite film on a large-sized velvet substrate, a preparation method thereof, and a battery, so as to solve at least one of the problems of the prior art, such as the difficulty of conformal growth of the perovskite film on a large-sized velvet substrate during ultrasonic spraying, poor perovskite crystallinity, low solution utilization rate, and poor repeatability.

[0005] In a first aspect, the present invention provides a method for preparing a perovskite film on a large-sized velvet substrate, comprising atomizing a perovskite precursor solution under an electric field to form a Taylor cone, spraying the solution on the large-sized velvet substrate, and heating and annealing the solution to obtain a perovskite film.

[0006] Furthermore, the height of the pyramids in the large-sized velvet substrate is 1-5 μm.

[0007] Furthermore, the preparation of the perovskite film is carried out in an electrospinning device, which includes a syringe, a needle tip and a base, and a voltage of 10 to 30 kV is applied between the needle tip and the base.

[0008] Furthermore, it specifically includes fixing the positive electrode on the needle tip and the negative electrode on the base, the base is a rotating structure, the perovskite precursor solution is pushed out from the syringe at a uniform speed, and a stable Taylor pile is obtained at the needle tip. The solution flies under the electric field and falls onto the large-sized velvet substrate on the base, and after annealing, a perovskite film is formed.

[0009] Furthermore, the uniform pushing speed is 0.005-0.035 mm / s.

[0010] Furthermore, the spraying time is 5 to 15 minutes.

[0011] Furthermore, the inner diameter of the needle tip is 0.90-2.41 mm, and the vertical distance between the needle tip and the large-size velvet base is 5-35 cm.

[0012] Furthermore, the heating annealing temperature is 80-140° C., and the time is 5-30 min.

[0013] Furthermore, before spraying the large-sized suede substrate, it is first cleaned under ultraviolet light for 5 to 10 minutes.

[0014] In a second aspect, the present invention provides a perovskite film prepared by the above method.

[0015] In a third aspect, the present invention provides a perovskite cell comprising the above-mentioned perovskite film, wherein the perovskite film is a light-absorbing layer.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] (1) The method of the present invention fully atomizes the perovskite precursor solution under high pressure to form a Taylor cone and produce a Coulomb explosion. During the flight, the increase in the charge-to-mass ratio of the colloid particles and the combined effect of the liquid tension cause the droplets to split multiple times, forming smaller droplets with a higher degree of atomization. At the same time, the generated electric field creates electrostatic attraction between the perovskite droplets and the substrate. The charged droplets are targeted and deposited on the conductive substrate, which can better achieve conformal growth of grains along the velvet pyramid, thereby reducing solution loss, improving solution utilization, and achieving higher perovskite crystallization quality and better repeatability.

[0018] (2) When the perovskite cell prepared by the method of the present invention is applied to the field of solar cells, it can effectively reduce the difficulty of preparing perovskite films on large-scale velvet substrates, with low cost, simple and repeatable preparation, and an open circuit voltage Voc of 1.8~2.0V, a conversion efficiency PCE ≥30%, a fill factor of 70%~85%, and a short circuit current density Jsc of 19~21 mA / cm 2 .

[0019] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. Throughout the drawings, the same reference symbols denote the same components.

[0021] Figure 1 A schematic diagram of a process for preparing a perovskite film according to the present invention;

[0022] Figure 2 This is a SEM image of the perovskite film prepared in the experimental sample 1 of the present invention;

[0023] Figure 3 This is a SEM image of the perovskite film prepared in experimental sample 2 of the present invention;

[0024] Figure 4 This is a SEM image of the perovskite film prepared in test sample 3 of the present invention;

[0025] Figure 5 is a SEM image of the perovskite film prepared in control sample 7 of the present invention;

[0026] Figure 6 This is a current density-voltage characteristic curve of the perovskite device prepared in the experimental sample 1 of the present invention;

[0027] Figure 7 This is a current density-voltage characteristic curve of the perovskite device prepared in experimental sample 2 of the present invention;

[0028] Figure 8 This is a current density-voltage characteristic curve of the perovskite device prepared in test sample 3 of the present invention;

[0029] Figure 9 Graph showing the current density-voltage characteristics of the perovskite device prepared in control sample 1 of the present invention;

[0030] Figure 10 Graph showing the current density-voltage characteristics of the perovskite device prepared in control sample 2 of the present invention;

[0031] Figure 11 3 is a current density-voltage characteristic curve of the perovskite device prepared in control sample 3 of the present invention;

[0032] Figure 12Graph showing the current density-voltage characteristics of the perovskite device prepared in control sample 7 of the present invention;

[0033] Figure 13 XRD comparison diagram of the perovskite film prepared in the experimental sample 1 and the control sample 7 of the present invention;

[0034] Figure 14 Schematic diagram of the process of preparing perovskite cells in Comparative Example 4 of the present invention.

[0035] Reference numerals:

[0036] 1- syringe, 2- needle tip, 3- base, 4- large-size velvet base, 5- electrode plate. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0038] A specific embodiment of the present invention discloses a method for preparing a perovskite film on a large-sized velvet substrate, comprising atomizing a perovskite precursor solution under an electric field to form a Taylor cone, spraying the solution on the large-sized velvet substrate, and heating and annealing the solution to obtain a perovskite film.

[0039] The method of the present invention fully atomizes the perovskite precursor solution under high pressure to form a Taylor cone and produce a Coulomb explosion. During the process of flight, the combined effect of the increased charge-to-mass ratio of the colloid particles and the liquid tension causes the droplets to split multiple times, forming smaller droplets and achieving a higher degree of atomization. Simultaneously, the generated electric field creates electrostatic attraction between the perovskite droplets and the substrate, allowing the charged droplets to be deposited in a targeted manner on the conductive substrate. This allows for better conformal growth of grains along the velvet pyramids, thereby reducing solution loss, improving solution utilization, and achieving higher perovskite crystallization quality and greater repeatability.

[0040] In a specific embodiment, the height of the pyramids in the large-scale velvet substrate is 1-5 μm.

[0041] In a specific embodiment, as Figure 1 As shown, the preparation of the perovskite film is carried out in an electrospinning device. The electrospinning device of the present invention is an existing device, for example, the DP30 basic electrospinning machine of Yunfan (Tianjin) Instrument Co., Ltd. The electrospinning device includes a syringe 1, a needle tip 2 and a base 3. The syringe 1 is used to place the perovskite precursor solution, and the base 3 is used to place the large-size velvet substrate.

[0042] Preferably, the syringe 1 is further connected to a needle tip 2 , the perovskite precursor solution is ejected from the needle tip 2 , and a voltage of 10 to 30 kV is applied between the needle tip 2 and the base 3 .

[0043] Specifically, the positive electrode is fixed on the needle tip 2, and the negative electrode is fixed on the base 3. The base 3 is a rotating structure. The perovskite precursor solution is pushed out from the syringe 1 at a uniform speed to obtain a stable Taylor pile at the needle tip. The solution flies under the electric field and falls onto the large-sized velvet substrate on the base 3. After annealing, a perovskite film is formed.

[0044] In a specific embodiment, the uniform pushing speed is 0.005-0.035 mm / s.

[0045] It should be noted that the above speed is matched with the voltage applied between the needle tip 2 and the base 3. If the pushing speed is too fast, it will cause liquid spraying or even discharge.

[0046] In a specific embodiment, the spraying time is 5 to 15 minutes, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, and 15 minutes.

[0047] The above-mentioned spraying time is set in combination with the pushing speed and the volatilization time of the perovskite precursor solution. If the spraying time is too long, the perovskite will be exposed to the air, and if the pushing time is too short, the film thickness will not be enough.

[0048] In a specific embodiment, the inner diameter of the needle tip is 0.90 ~ 2.41 mm, for example, 0.90mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, and the vertical distance between the needle tip and the large-size suede base is 5 ~ 35 cm, for example, 5cm, 7cm, 9cm, 11cm, 13cm, 15cm, 17cm, 19cm, 21cm, 23cm, 25cm, 27cm, 29cm, 31cm, 33cm, 35cm. In a specific embodiment, the heating annealing temperature is 80-140°C, for example, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, and the time is 5-30 min, for example, 5 min, 7 min, 9 min, 11 min, 13 min, 15 min, 17 min, 19 min, 21 min, 23 min, 25 min, 27 min, 29 min, 30 min.

[0049] It should be noted that if the temperature is too low, the phase transformation of perovskite cannot be completed, and if the temperature is too high, the perovskite will decompose.

[0050] In a specific embodiment, the solvent in the perovskite precursor solution is dimethylformamide and / or dimethyl sulfoxide, and the concentration of perovskite in the precursor solution is 1.5-2.5 mol / L.

[0051] It should be noted that in order to quickly atomize the solution, the required perovskite solution concentration is greater than 1.5 mol / L, and in order to ensure the dissolution of the perovskite solute, the required perovskite solution concentration is less than 2.5 mol / L.

[0052] In a specific embodiment, the perovskite includes the following raw materials in parts by weight: 538-897 parts of lead iodide, 192-320 parts of iodomethane, 98-163 parts of lead bromide, 82-136 parts of cesium iodide, 18-33 parts of lead chloride and 10-16 parts of methylammonium chloride.

[0053] Specifically, the perovskite precursor solution is stirred at room temperature for 10 to 14 hours and then added to the syringe of the electrospraying device.

[0054] In a specific embodiment, the perovskite film has an ABX3 type crystal structure, wherein A is an organic cation or a mixture of an organic cation and an inorganic cation, such as CH4N2 + , CH5N + , Cs + One or more of the following, B is Pb 2+ , X is Cl - Br - , I - One or more of the .

[0055] In a specific embodiment, before spraying the large-scale suede substrate, it is first cleaned under ultraviolet light for 5 to 10 minutes.

[0056] It should be noted that the large-sized textured substrate of the present invention is a substrate such as silicon, and also includes spraying the perovskite precursor solution after forming a hole transport layer on the large-sized textured substrate to obtain a perovskite film.

[0057] Another specific embodiment of the present invention discloses a perovskite film prepared by the above method.

[0058] Another specific embodiment of the present invention discloses a perovskite cell including the above-mentioned perovskite film.

[0059] When the perovskite cell prepared by the method of the present invention is applied to the field of solar cells, the difficulty of preparing the perovskite film on a large-scale suede substrate can be effectively reduced. The cost is low, the preparation is simple and reproducible, and the open circuit voltage Voc is 1.8-2.0V, the conversion efficiency PCE is ≥30%, the fill factor is 70%-85%, and the short circuit current density Jsc is 19-21 mA / cm 2 .

[0060] In a specific embodiment, the perovskite film is a light absorbing layer.

[0061] Specifically, the perovskite cell is stacked with a back electrode, a hole transport layer, a light absorption layer, an electron transport layer, a metal electrode and an anti-reflection layer in sequence from bottom to top.

[0062] Another specific embodiment of the present invention discloses a method for preparing the above-mentioned perovskite battery, comprising the following steps:

[0063] (1) Prepare the back electrode on the back of a large-scale suede substrate;

[0064] (2) Preparing a hole transport layer on the front surface of a large-scale velvet substrate;

[0065] (3) preparing a perovskite film on the hole transport layer;

[0066] (4) preparing an electron transport layer on the perovskite film;

[0067] (5) preparing a metal electrode on the electron transport layer;

[0068] (6) Preparing an anti-reflection layer on the metal electrode to obtain the perovskite cell.

[0069] Specifically, in step (1), a back electrode is prepared on the back of a large-sized suede substrate by vacuum evaporation of silver.

[0070] Specifically, in step (2), a SAM (self-assembled monolayer) solution is spin-coated on the front surface of the large-scale suede substrate, and heated and annealed to obtain a SAM hole transport layer.

[0071] The spin coating speed is 2000~6000rpm, the spin coating time is 20~40s, the heating annealing temperature is 80~120℃, and the annealing time is 5~20min. Specifically, in step (4), vacuum evaporation of C 60 and atomically deposited SnO2 to form an electron transport layer on the perovskite film.

[0072] Specifically, in step (5), silver is vacuum evaporated as the metal electrode.

[0073] Specifically, in step (6), the anti-reflection layer is obtained by vacuum evaporation of MgF2.

[0074] Another specific embodiment of the present invention discloses a solar cell device, including the above-mentioned perovskite cell.

[0075] The technical solution of the present invention is further explained below in conjunction with specific embodiments.

[0076] Example 1

[0077] A method for preparing a perovskite film on a large-scale textured silicon substrate according to this embodiment includes the following steps:

[0078] (1) The perovskite precursor solution was stirred at room temperature for 12 h in a nitrogen atmosphere, filtered, and added to the syringe in the electrospraying setup. The syringe was fixed on the electrospinning device, and the large-scale textured silicon substrate was placed on a rotatable base.

[0079] (2) Turn on the electrospinning equipment, apply 20 kV high voltage alternating current between the needle tip and the base, and simultaneously push the perovskite precursor solution in the syringe at a uniform speed of 0.015 mm / s, spray for 8 minutes, and anneal at 120°C for 20 minutes to form a perovskite film, wherein the inner diameter of the needle tip is 0.90 mm, and the vertical distance between the needle tip and the large-size velvet base is 35 cm;

[0080] The perovskite precursor in this embodiment was prepared by dissolving 789 mg of lead iodide, 282 mg of iodomethane, 143 mg of lead bromide, 120 mg of cesium iodide, 29 mg of lead chloride, and 14 mg of methylamine chloride in 1 mL of a mixed solution of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0081] Example 2

[0082] A method for preparing a perovskite film on a large-scale textured silicon substrate according to this embodiment includes the following steps:

[0083] (1) The perovskite precursor solution was stirred at room temperature for 10 h in a nitrogen atmosphere, filtered, and added to the syringe in the electrospraying setup. The syringe was fixed on the electrospinning device, and the large-scale textured silicon substrate was placed on a rotatable base.

[0084] (2) Turn on the electrospinning equipment, apply 10 kV high voltage alternating current between the needle tip and the base, and simultaneously push the perovskite precursor solution in the syringe at a uniform pushing speed of 0.005 mm / s, spray for 15 minutes, and anneal at 140 ° C for 30 minutes to form a perovskite film, wherein the inner diameter of the needle tip is 1.30 mm, and the vertical distance between the needle tip and the large-size velvet base is 20 cm;

[0085] The perovskite precursor in this embodiment was prepared by dissolving 538 mg of lead iodide, 192 mg of iodomethane, 98 mg of lead bromide, 82 mg of cesium iodide, 18 mg of lead chloride, and 10 mg of methylamine chloride in 1 mL of a mixed solution of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0086] Example 3

[0087] A method for preparing a perovskite film on a large-scale textured silicon substrate according to this embodiment includes the following steps:

[0088] (1) The perovskite precursor solution was stirred at room temperature for 14 h in a nitrogen atmosphere, filtered, and added to the syringe in the electrospraying setup. The syringe was fixed on the electrospinning device, and the large-scale textured silicon substrate was placed on a rotatable base.

[0089] (2) Turn on the electrospinning equipment, apply 30 kV high voltage alternating current between the needle tip and the base, and simultaneously push the perovskite precursor solution in the syringe at a uniform pushing speed of 0.035 mm / s, spray for 5 minutes, and anneal at 140 ° C for 5 minutes to form a perovskite film, wherein the inner diameter of the needle tip is 2.41 mm, and the vertical distance between the needle tip and the large-size velvet base is 5 cm;

[0090] The perovskite precursor in this embodiment was prepared by dissolving 897 mg of lead iodide, 320 mg of iodomethane, 163 mg of lead bromide, 136 mg of cesium iodide, 33 mg of lead chloride, and 16 mg of methylamine chloride in 1 mL of a mixed solution of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0091] Comparative Example 1

[0092] The preparation method of the perovskite film in this comparative example is the same as that in Example 1, except that in step (2), the voltage is 5 kV.

[0093] Comparative Example 2

[0094] The preparation method of the perovskite film in this comparative example is the same as that in Example 1, except that in step (2), the pushing speed is 0.05 mm / s.

[0095] Comparative Example 3

[0096] The preparation method of the perovskite film in this comparative example is the same as that in Example 1, except that in step (2), the spraying time is 25 minutes.

[0097] Comparative Example 4

[0098] The preparation method of the perovskite film in this comparative example is the same as that in Example 1, except that, instead of applying voltage between the needle and the base, an electrode 5 is provided at the upper end of the syringe, and voltage is applied between the electrode 5 and the base 3, placing the syringe in the electric field. Figure 14 shown.

[0099] Comparative Example 5

[0100] The preparation method of the perovskite film in this comparative example is the same as that in Example 1, except that the vertical distance between the needle tip and the large-sized suede substrate is 40 cm.

[0101] Comparative Example 6

[0102] The preparation method of the perovskite film in this comparative example is the same as that in Example 1, except that the inner diameter of the needle tip is 0.55 mm.

[0103] Application Example 1

[0104] The height of the textured pyramids in the substrate of the following perovskite battery preparation is 1~5μm.

[0105] This application example is a method for preparing a perovskite battery, which specifically includes the following steps:

[0106] (1) Forming a back electrode on the back of a large-scale textured silicon substrate by vacuum evaporation of silver;

[0107] (2) The SAM solution was spin-coated on the front of a clean large-scale suede silicon substrate at 3000 rpm for 30 s, and then the large-scale suede silicon substrate after the SAM solution was spin-coated was annealed at 100°C for 10 minutes to form a SAM hole transport layer on the large-scale suede silicon substrate;

[0108] The SAM solution is prepared by dissolving 1 mg of Me-2PACz (dimethoxycarbazole) in ethanol and stirring the mixture.

[0109] (3) Preparing a perovskite film on the hole transport layer using the methods of Examples 1-3 and Comparative Examples 1-6 respectively;

[0110] (4) Vacuum evaporation C 60 and atomically deposited SnO2 to form an electron transport layer on the perovskite film;

[0111] (5) Vacuum evaporation of silver as a metal electrode on the electron transport layer;

[0112] (6) An anti-reflection layer was obtained by vacuum evaporation of MgF2 on the metal electrode, and the perovskite cells of the experimental samples 1-3 and the perovskite cells of the control samples 1-6 were obtained respectively.

[0113] The preparation of the perovskite cell of control sample 7 is as follows:

[0114] (1) Forming a back electrode on the back of a large-scale textured silicon substrate by vacuum evaporation of silver;

[0115] (2) The SAM solution was spin-coated on the front of a clean large-scale textured silicon substrate at 3000 rpm for 30 s, and then the large-scale textured silicon substrate after spin-coating the SAM solution was annealed at 100 °C for 10 minutes to form a SAM hole transport layer on the large-scale textured silicon substrate;

[0116] The SAM solution is prepared by dissolving 1 mg of Me-2PACz (dimethoxycarbazole) in ethanol and stirring the mixture.

[0117] (3) The perovskite precursor solution (the same as in Example 1) was stirred at room temperature for 12 hours under a nitrogen atmosphere, filtered, and then spin-coated on the SAM hole transport layer at 4000 rpm for 30 seconds, and then annealed at 120°C for 20 minutes to form a perovskite film;

[0118] (4) Vacuum evaporation of C 60 and atomically deposited SnO2 to form an electron transport layer on the perovskite film;

[0119] (5) Silver is used as electrode by vacuum evaporation;

[0120] (6) Finally, an anti-reflection layer was obtained by vacuum evaporation of MgF2 to obtain the perovskite cell of control sample 4.

[0121] (I) SEM images of the perovskite films prepared in Examples 1-3 and control sample 7, respectively. Figure 2-4 5. As shown in FIG5. By comparison, it can be seen that the perovskite film prepared by the method of the present invention has higher shape retention and high repeatability on a large-scale textured substrate.

[0122] (II) XRD patterns of the perovskite films prepared by test sample 1 and control sample 7 were tested respectively, as shown in Figure 13 As shown in FIG. 3 , it can be seen from the comparison that the perovskite film prepared by the method of the present invention has better crystallinity.

[0123] (III) The performance of the perovskite cells of test samples 1-3 and control samples 1-7 was tested. The solar simulator used in the test was Keitheley 2400, Enli Technology Co.; the test condition for the current density-voltage curve of the perovskite cells was AM 1.5 G. The results are shown in Table 1 and Figure 6-12 shown.

[0124]

[0125] Compared with the test sample 1, the control sample 4 adopts the electrostatic spraying method of comparative example 4, and the electric field strength is weak, and the voltage required for the Coulomb explosion cannot be reached at the needle tip. The solution of the method of embodiment 1 can form a Taylor cone at the needle tip and produce a Coulomb explosion, and during the flight, the increase in the charge-to-mass ratio of the colloid particles and the combined effect of the liquid tension can cause the droplets to split multiple times to form smaller droplets. The perovskite solution is dispersed more evenly when it reaches the substrate, which is more conducive to improving the crystallinity of the perovskite on the large velvet surface. At the same time, the electric field generated causes electrostatic attraction between the perovskite droplets and the substrate, and the charged droplets are targeted and deposited along the pyramid shape of the substrate on the conductive substrate. Compared with other preparation methods, this method can better achieve the conformal growth of grains along the velvet pyramid, reduce solution loss, improve solution utilization, and make the perovskite crystallization quality higher and more repeatable.

[0126] The above results demonstrate that the perovskite films prepared using this method exhibit improved shape retention, superior crystallization quality, and high reproducibility, effectively reducing the difficulty of preparing perovskite films on large-scale textured substrates. This method can also produce high-performance tandem cell devices, with the resulting perovskite / large-scale textured silicon tandem cell achieving efficiencies exceeding 30%.

[0127] Since the control sample 5 is too far away from the base, the solution evaporates in large quantities during the flight process, resulting in a small amount of perovskite solution reaching the substrate. After annealing, a loose perovskite film with holes is formed, forming a short-circuit battery.

[0128] In control sample 6, due to the smaller needle diameter, the amount of liquid ejected is small, which is insufficient to form a complete perovskite film, and a large number of voids are formed, resulting in a short-circuited battery.

[0129] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a perovskite film on a large-scale textured substrate, characterized in that: The method includes atomizing a perovskite precursor solution under an electric field to form a Taylor cone and generate a Coulomb explosion and multiple splitting of droplets to form smaller droplets, spraying the droplets on a large-sized suede substrate, and heating and annealing to obtain a perovskite film. The height of the velvet pyramids in the large-size velvet substrate is 1-5 μm; The perovskite film is prepared in an electrospinning device, which includes a syringe, a needle tip and a base, and a voltage of 10 to 30 kV is applied between the needle tip and the base; The perovskite precursor solution is ejected from the syringe at a uniform speed, wherein the speed of the uniform ejection is 0.005-0.035 mm / s, and the spraying time is 5-15 min; The inner diameter of the needle tip is 0.90–2.41 mm, and the vertical distance between the needle tip and the large-scale velvet base is 19–35 cm; The heating annealing temperature is 80~140℃ and the time is 5~30min; The solvent in the perovskite precursor solution is dimethylformamide and / or dimethyl sulfoxide, and the concentration of perovskite in the precursor solution is 1.5-2.5 mol / L.

2. The method for preparing a perovskite film on a large-scale textured substrate according to claim 1, characterized in that: Specifically, the positive electrode is fixed on the needle tip and the negative electrode is fixed on the base. The base is a rotating structure. The perovskite precursor solution is pushed out of the syringe at a uniform speed to obtain a stable Taylor pile at the needle tip. The solution flies under the electric field and falls onto the large-sized velvet substrate on the base. After annealing, a perovskite film is formed.

3. The method for preparing a perovskite film on a large-scale textured substrate according to claim 2, characterized in that: The uniform pushing speed is 0.015-0.035 mm / s, and the spraying time is 8-15 minutes.

4. The method for preparing a perovskite film on a large-scale textured substrate according to claim 2, wherein: The inner diameter of the needle tip is 1.0 ~2.4 mm, and the vertical distance between the needle tip and the large-size velvet base is 21 ~33 cm.

5. The method for preparing a perovskite film on a large-scale textured substrate according to claim 1, characterized in that: The heating annealing temperature is 85~135℃ and the time is 7~29min.

6. The method for preparing a perovskite film on a large-scale textured substrate according to claim 1, wherein: Before spraying the large-scale suede substrate, it was cleaned under ultraviolet light for 5 to 10 minutes.

7. A perovskite film prepared by the method according to any one of claims 1 to 6.

8. A perovskite cell comprising the perovskite film according to claim 7, characterized in that: The perovskite film is a light-absorbing layer.

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