TWI793826B - Method for producing perovskite film, perovskite substrate and perovskite solar cell - Google Patents

Abstract

The present invention relates to a method for producing a perovskite film, a perovskite substrate and a perovskite solar cell. The method for producing the perovskite film utilizes a method by using an ultrasonic resonance to aerosolize a perovskite precursor solution into a plurality of droplets with a specific particles size and utilizes gas to spray the plurality of droplets on a silicon substrate, thereby increase an area of the perovskite film and enhancing an uniformity of the perovskite film. The perovskite substrate containing the resulted perovskite film can be applied to the perovskite solar cell, thereby enhancing effect of the perovskite solar cell.

Description

Manufacturing method of perovskite thin film, perovskite substrate and perovskite solar cell

The present invention relates to a method for manufacturing a perovskite film, a perovskite substrate and a perovskite solar cell, and in particular to a method for manufacturing a perovskite film with large area and high uniformity, a perovskite Substrates and perovskite solar cells.

Perovskite materials are made by mixing organic and inorganic substances. The general chemical formula of perovskite materials can be represented by ABX ₃ , where A represents organic cations, such as: HC(NH ₂ ) ²⁺ and CH ₃ NH ³⁺ , B represents metal cations, such as Pb ²⁺ , Ge ²⁺ and Sn ²⁺ , X represents monovalent anions, such as halogen anions.

Perovskite materials have good absorption of visible light and have a wide range of light absorption, so thin films made of perovskite materials (hereinafter referred to as perovskite material thin films) are often used as the active layer of solar cells. . High short-circuit current can be generated by using a small amount of perovskite material, and the fabricated solar cell has a high open-circuit voltage, so the perovskite solar cell has good photoelectric conversion efficiency (power conversion efficiency, PCE).

The traditional manufacturing method of perovskite thin film is to manufacture perovskite thin film on the substrate by spin coating or vapor deposition, so as to obtain the perovskite substrate. The advantages of the spin coating method are time saving and low cost, but the coating area is limited, and the uniformity of the prepared perovskite film is poor. In addition, although the perovskite film produced by evaporation has high uniformity, the evaporation area is still limited.

In view of this, there is an urgent need to develop a new method of manufacturing perovskite thin films to improve the above-mentioned shortcomings of conventional perovskite thin film manufacturing methods, perovskite substrates and perovskite solar cells.

In view of the above-mentioned problems, one aspect of the present invention is to provide a method of manufacturing a perovskite film, which uses ultrasonic vibration and gas spraying of a perovskite precursor solution to increase the amount of calcium produced. The area of the titanium ore film is increased and its uniformity is improved.

Another aspect of the present invention is to provide a perovskite substrate comprising the aforementioned perovskite thin film.

Another aspect of the present invention is to provide a perovskite solar cell, which includes the aforementioned perovskite thin film.

According to an aspect of the present invention, a method for manufacturing a perovskite thin film is proposed. In the manufacturing method, the silicon substrate is first sprayed to form a perovskite coating film on the surface of the silicon substrate, wherein the spraying treatment includes: providing a perovskite precursor solution, an atomization step and a coating step. In detail, the perovskite precursor solution is atomized to generate a plurality of droplets, wherein the atomization step is to atomize the perovskite precursor solution by means of ultrasonic vibration. Next, a coating step is performed to form a perovskite coating film, wherein the coating step uses gas to coat the droplets on the surface. Then, heat treatment is performed on the perovskite coating film to obtain a perovskite film, wherein the temperature of the heat treatment is not less than 60°C.

According to an embodiment of the present invention, when the spraying process includes a single-stage spraying step, the perovskite precursor of the perovskite precursor solution includes a halide salt of a group IVA element and a halide salt of an alkylamine.

According to another embodiment of the present invention, when the spraying process includes a two-stage spraying step, the two-stage spraying step includes a first spraying step and a second spraying step, and the perovskite of the perovskite precursor solution in the first spraying step The ore precursor includes one of the halide salts of group IVA elements and the halide salts of alkylamines, and the perovskite precursor of the perovskite precursor solution in the second spraying step includes halide salts and alkylamines of group IVA elements The other of the halide salts.

According to yet another embodiment of the present invention, the particle size of these liquid droplets is not greater than 10 μm.

According to yet another embodiment of the present invention, the gas includes a first gas and a second gas.

According to yet another embodiment of the present invention, the first gas flow direction of the first gas and the second gas flow direction of the second gas form an included angle, and the included angle is 20° to 160°.

According to another aspect of the present invention, a perovskite substrate is provided. The perovskite substrate includes a silicon substrate and a perovskite film disposed on the silicon substrate, wherein the coverage of the perovskite film on the silicon substrate is greater than 75%, and the grain size of the perovskite film is 2 μm to 5 μm.

According to yet another embodiment of the present invention, one of the perovskite films has an area greater than 22500 mm ² .

According to another embodiment of the present invention, the XRD spectrum of the perovskite thin film has a diffraction peak intensity ratio between (220) crystallographic direction and (310) crystallographic direction greater than 1.2 and not greater than 1.8.

According to another aspect of the present invention, a perovskite solar cell is provided. The perovskite solar cell includes a silicon substrate, a photoelectric conversion layer and an electrode layer, wherein the photoelectric conversion layer is arranged between the silicon substrate and the electrode layer. The photoelectric conversion layer includes a perovskite thin film, and an electron transport layer or a hole transport layer. When the photoelectric conversion layer includes a perovskite film and an electron transport layer, the electron transport layer is disposed between the perovskite film and the silicon substrate, and the coverage of the perovskite film on the electron transport layer is greater than 75%; or when When the photoelectric conversion layer includes a perovskite film and a hole transport layer, the hole transport layer is disposed between the perovskite film and the electrode layer, and the coverage of the perovskite film on the silicon substrate is greater than 75%.

According to an embodiment of the present invention, the XRD spectrum of the perovskite thin film has a diffraction peak intensity ratio between the (220) crystallographic direction and the (310) crystallographic direction greater than 1.2 and not greater than 1.8.

The manufacturing method of the perovskite thin film, the perovskite substrate and the perovskite solar cell of the present invention are applied, wherein the perovskite precursor solution is atomized into a plurality of droplets with a specific particle size by means of ultrasonic vibration, and the The gas sprays these droplets on the silicon substrate, thereby increasing the area and improving the uniformity of the fabricated perovskite film. The perovskite substrate containing the prepared perovskite thin film can be applied to perovskite solar cells to improve the performance of the perovskite solar cells.

The making and using of embodiments of the invention are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are illustrative only and do not limit the scope of the invention.

Please refer to FIG. 1 , the method 100 for manufacturing a perovskite film first sprays a silicon substrate to form a perovskite coating on the surface of the silicon substrate, as shown in operation 110 . In the spray coating process, a perovskite precursor solution is firstly provided, as shown in step 111 . The perovskite precursor solution includes a solvent and a perovskite precursor. The solvent is not particularly limited, and may be a solvent commonly used by those skilled in the art of the present invention, such as dimethylformamide (DMF), dimethylsulfoxide (DMSO) and isopropanol (IPA).

In some embodiments, according to the number of spraying steps carried out in the subsequent spraying process (detailed later), the perovskite precursors sprayed may include but are not limited to halide salts of group IVA elements and/or alkylamines. halide salts. Preferably, the group IVA element can be germanium, tin and lead, the halogen element of the halide salt can be chlorine, bromine and iodine, and the alkyl group of the alkylamine is, for example, methyl.

In an embodiment of a single-stage spraying step, the perovskite precursor may include a halide salt of a Group IVA element and a halide salt of an alkylamine. In an embodiment of the two-stage spraying step, the two-stage spraying step includes a first spraying step and a second spraying step. The perovskite precursor used in the first spraying step includes one of the halide salts of group IVA elements and the halide salts of alkylamines, and the perovskite precursor used in the second spraying step includes halide salts of group IVA elements And the other one of halide salt of alkylamine to make perovskite coating film. The "stage" referred to here depends on the number of layers sprayed with the perovskite precursor solution.

In detail, take the perovskite film with the general formula HC(NH ₂ )PbI ₃ as an example, when the perovskite precursor solution is a solution containing PbI ₂ and methyl ammonium iodide (CH ₃ NH ₃ I, MAI) When using a solution, the perovskite precursor solution can be sprayed on the silicon substrate once or repeatedly to form a perovskite coating film. When the perovskite precursor solution is a solution containing _PbI2 or methylammonium iodide, in some specific examples, the solution containing _PbI2 or methylammonium iodide is first sprayed on the silicon substrate to form a corresponding coating film, and then spray a solution containing the other on the aforementioned coating film, so that PbI ₂ reacts with methyl ammonium iodide to form a perovskite coating film.

In some other embodiments, the manufacturing method 100 of the perovskite thin film may combine a single-stage spraying step and a two-stage spraying step to carry out the spraying process, and the combined spraying step may be called a multi-stage spraying step. In terms of efficacy, the one-stage spraying step can save time, and the two-stage (or multi-stage) spraying step can further improve the uniformity and thickness adjustment of the prepared perovskite film.

The "uniformity" referred to in the present invention is evaluated using the coverage rate described later, wherein the coverage rate is expressed by the quotient obtained by dividing the area of the perovskite film by the area of the silicon substrate. When the coverage is greater than 75%, this perovskite film has good uniformity. This coverage is affected by the number of pores in the perovskite film and the film-forming property of the coating. When the perovskite film has fewer pores and better film-forming properties, the coverage rate is higher.

In some embodiments, the viscosity of the perovskite precursor solution may not be greater than 35 cp. When the viscosity is within the aforementioned range, it is beneficial for spraying, thereby increasing the area of the perovskite film, improving its uniformity and thickness adjustability.

After step 111 , the perovskite precursor solution is atomized to generate a plurality of droplets, as shown in step 112 . In some embodiments, the aforementioned atomization step is performed using a spraying device, and the spraying device may be a spraying device containing one gas or two gases. Referring to FIG. 2A and FIG. 2B , the spraying device 200 includes a supply tank 210 , an ultrasonic vibrating element 220 , a spray port 230 , a first gas nozzle 240 and a second gas nozzle 250 . In detail, in the ultrasonic oscillator 220, the ultrasonic generator generates an electronic signal of a specific frequency, and the electronic signal causes the piezoelectric ceramic to generate a mechanical vibration of the same frequency, and then the amplitude of the mechanical vibration is amplified by the horn.

Further, the perovskite precursor solution in the supply tank 210 is pressurized by the motor and sprayed out through the spray port 230 , and the sprayed perovskite precursor solution is refined into liquid droplets by the amplified mechanical vibration. In addition, the mechanical vibration can mix the perovskite precursor solution to make the grains of the perovskite film more uniform (ie, the grain size is more uniform). In some embodiments, the aforementioned frequency may be 20 kHz to 150 kHz, and preferably may be 25 kHz to 125 kHz. When the frequency is within the aforementioned range, it is beneficial to the refinement and atomization of droplets, thereby improving the uniformity of the manufactured perovskite film. Furthermore, the particle size of the generated droplets may not be greater than 10 μm, and preferably may be 2 μm to 9 μm. When the droplet size is greater than 10 μm, the uniformity of the perovskite film is improved and the coating area is increased.

In some embodiments, the feed tank 210 may be a syringe. The syringe is equipped with a single tube syringe, and its switching valve is set above the syringe. The switching valve is controlled by a motor sensor, and the motor is used to supplement or spray the perovskite precursor solution. The motor sensor is designed into three groups, and its functions are the upper limit, the pumping point and the lower limit. The pumping point is designed to remove the air in the injection cylinder as a reference point, so that the utilization rate of the perovskite precursor solution can be greater than 80%. In detail, a symmetrical mechanism is used to push the syringe to control the ejection speed of the perovskite precursor solution. The switching valve is controlled by an electronically controlled transposition valve, and the material of the transposition valve is polyetheretherketone (PEEK) and polytetrafluoroethylene (PTFE), which are chemical resistant and easy to assemble and maintain. In addition, when the syringe is used as the feed tank 210, the residual (ie, unused) perovskite precursor solution can be recovered by pumping it out with gas.

After step 112 , a coating step is performed to form a perovskite coating film, as shown in step 113 . In some embodiments, the first gas nozzle 240 and the second gas nozzle 250 respectively generate the first gas and the second gas, and the two gases are sprayed to the thinned liquid droplets, so that the liquid droplets are sprayed on the surface of the silicon substrate superior. The gas flow directions of the first gas nozzle 240 and the second gas nozzle 250 are not parallel to the extending direction of the spray opening 230 . In some embodiments, the gas flow direction of the first gas nozzle 240 and the second gas nozzle 250 is perpendicular to the extension direction of the spray port 230 . The gas flow directions of these two gases form an included angle θ, and the included angle θ can be from 20° to 160°. When the included angle θ is 20° to 160°, the liquid droplets can be evenly sprayed on the surface of the silicon substrate, and the spraying area can be increased. Preferably, the included angle θ may be 45° to 135°. The types of the aforementioned first gas and second gas are not particularly limited, but the purpose is not to react with the perovskite precursor solution. Preferably, specific examples of the first gas and the second gas may include air or nitrogen.

The sum of the pressures of the two gases can be maintained at a certain value (for example: 0 Psi to 70 Psi), so as to control the spraying area of the droplets through the relative fluctuation of the pressures of the two gases, as shown in FIG. 3 . In detail, the flow field of the gas after the collision is controlled in this way, that is, the space occupied by the sprayed droplets, and the swing of the spraying direction is regulated by the pressure of the two gases. For example, the sum of the pressures can be 60Psi. When spraying from the side close to the second gas nozzle 250 to the side close to the first gas nozzle 240, the pressure of the first gas gradually decreases from 60Psi, while the pressure of the second gas decreases from 60Psi to 1Psi is gradually increased. When spraying in the middle of the first gas nozzle 240 and the second gas nozzle 250 , the pressures of the first gas and the second gas are equal. Then continue spraying toward the side close to the first gas nozzle 240, the pressure of the first gas gradually drops to 1Psi, and the pressure of the second gas gradually increases to 60Psi. When the sum of the pressures of the two gases is maintained at a constant value, it is beneficial to uniformly spray the liquid droplets on the surface of the silicon substrate, thereby improving the uniformity of the perovskite film, and thus increasing the coating area.

In some embodiments, the pressure of the two gases undergoes a cycle (for example: increasing from 1Psi to 60Psi and then decreasing to 1Psi) time is not particularly limited, but for the purpose of uniformly spraying liquid droplets on the surface of the silicon substrate, It can be from 1 to 10 minutes. In some specific examples, the flow rate of the two gases may be 0.05 mL/min to 35 mL/min, so as to maintain the sum of the pressures of the two gases at a constant value. When the flow rate is in the aforementioned range, the liquid droplets can be evenly sprayed on the surface of the silicon substrate, and the spraying area can be increased. Preferably, the flow rate may be 0.5 mL/min to 1 mL/min.

In some embodiments, the aforementioned coating area may be greater than 22500 mm ² (for example, a rectangle greater than 150 mm×150 mm). When the coating area is within the aforementioned range, the prepared perovskite thin film is suitable for application in perovskite solar cells. In some embodiments, the coating amount can be 0.1 mL/min to 0.5 mL/min, and preferably 0.25 mL/min. When the coating amount is in the aforementioned range, it is beneficial for spraying, thereby increasing the area of the perovskite film and improving its uniformity and thickness adjustment.

Specific examples of the silicon substrate include but are not limited to a silicon substrate coated with a metal oxide layer, and the silicon substrate is preferably a crystalline silicon (c-Si) substrate. In addition, specific examples of the metal oxide layer may include but not limited to indium tin oxide (ITO). In some preferred embodiments, the thickness of the metal oxide layer can be 70nm to 130nm, so as to improve the light absorption of the fabricated perovskite film and maintain good electrical conductivity. In some specific examples, the metal oxide layer can be evaporated on the silicon substrate, and before the evaporation, the silicon substrate can be treated with ultraviolet light and ozone (for example, after 30 minutes of treatment time) to clean the surface of the silicon substrate .

After operation 110 , heat treatment is performed on the perovskite coating film to obtain a perovskite film, as shown in operation 120 . The heat treatment temperature is not less than 60°C. If the temperature is lower than 60°C, the perovskite precursor cannot form perovskite, and the resulting film cannot be used in perovskite solar cells. The heat treatment temperature is preferably 60°C to 120°C. In some embodiments, the heat treatment time may be 20 minutes to 60 minutes. When the heat treatment time is within the aforementioned range, the perovskite precursor can be beneficial to form the perovskite film.

Another aspect of the present invention is to provide a perovskite substrate. Referring to FIG. 4 , the perovskite substrate 400 includes a silicon substrate 410 and a perovskite film 420 disposed on the silicon substrate 410 . The perovskite thin film 420 can be manufactured by the above-mentioned manufacturing method of the perovskite thin film. In some embodiments, the grain size of the perovskite thin film 420 is 2 μm to 5 μm. When the grain size of the perovskite thin film 420 is in the aforementioned range, the grain uniformity and coverage of the manufactured perovskite thin film 420 can be improved, which is beneficial for application in perovskite solar cells. In addition, the coverage of the perovskite thin film 420 on the silicon substrate 410 may be greater than 75%. If the coverage is not greater than 75%, the perovskite substrate 400 including the perovskite thin film 420 is difficult to be applied to perovskite solar cells. In some embodiments, the thickness of the perovskite film 420 may be 200 nm to 3 μm, and preferably 300 nm to 2 μm. When the thickness of the perovskite thin film 420 is within the aforementioned range, the uniformity and coverage of the manufactured perovskite thin film 420 can be improved, which is beneficial for application in perovskite solar cells. In some embodiments, the area of the perovskite thin film 420 is greater than 22500 mm ² , which is beneficial for application in perovskite solar cells.

In some embodiments, the XRD pattern of the perovskite thin film 420 has a diffraction peak intensity ratio of (220) crystallographic direction to (310) crystallographic direction greater than 1.2 and not greater than 1.8. When the diffraction peak intensity ratio is within the aforementioned range, the perovskite thin film 420 has good absorption of visible light, which is beneficial for application in perovskite solar cells.

The perovskite thin film of the present invention is suitable for use in perovskite solar cells, wherein the perovskite thin film is used as the active layer of the solar cell. Please refer to FIG. 5A , the perovskite solar cell 500 may include a silicon substrate 510 , a photoelectric conversion layer 520 and an electrode layer 530 , wherein the photoelectric conversion layer 520 is disposed between the silicon substrate 510 and the electrode layer 530 . Please refer to FIG. 5B , in some application examples, the photoelectric conversion layer 520 includes a perovskite film 521 and an electron transport layer 522 , and the electron transport layer 522 is disposed between the perovskite film 521 and the silicon substrate 510 . Please refer to FIG. 5C , in some other application examples, the photoelectric conversion layer 520 includes a perovskite film 521 and a hole transport layer 523 , and the electron transport layer 522 is disposed between the perovskite film 521 and the electrode layer 530 . The silicon substrate 510, the electron transport layer 522, and the perovskite absorbing layer 521 can respectively use the crystalline silicon substrate, metal oxide layer, and perovskite thin film used in the manufacturing method of the aforementioned perovskite thin film.

The materials of the electron transport layer 522 , the hole transport layer 523 and the electrode layer 530 are not particularly limited, but are suitable for the purpose of application in the perovskite solar cell 500 . In some specific examples, the material of the hole transport layer 523 may include polydioxyethylenethiophene: styrene sulfonic acid (PEDOT: PSS) and 2,2',7,7'-tetrakis[N,N-bis( 4-methoxyphenyl)amino]-9,9'-spirobifluorene (2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl) amino]-9,9'- spirobifluorene, Spiro-OMeTAD). In addition, the material of the electron transport layer 522 may include 6,6-phenyl-C61-butyric acid methyl ester (6,6-phenyl-C61-butyric acid methyl ester, PC61BM), 6,6-phenyl-C71-butyl acid methyl ester (6,6-phenyl-C71-butyric acid methyl ester, PC71BM), zinc oxide and titanium oxide. Preferably, the hole transport layer 523 uses solid Spiro-OMeTAD with high thermal stability to improve the stability of the perovskite solar cell. In some embodiments, the electron-transporting layer 522 or the hole-transporting layer 523 can be omitted to reduce the energy loss formed at the interface of each layer. For example, perovskite solar cells using glass substrates must be combined with silicon crystals in tandem cells, which easily leads to complex process structures and interface loss. In addition, the material of the electrode layer 530 may include conductive metals, such as gold and aluminum.

The following examples are used to illustrate the application of the present invention, but they are not intended to limit the present invention. Anyone skilled in this art can make various changes and modifications without departing from the spirit and scope of the present invention.

Preparation of Perovskite Thin Films

Example 1

The perovskite thin film of Example 1 was firstly cleaned with the RCA standard cleaning process to clean the silicon-based substrate, and then the surface of the silicon-based substrate was cleaned with ultraviolet light and ozone. Then deposit an ITO film with a thickness of 70nm to 130nm on the surface of the crystalline silicon wafer by sputtering. Then use _the spraying device of the present invention to spray the perovskite precursor solution (10wt.% to 15wt.% of MAI and 5mol% to 10mol% PbI solution in one-stage mode or two-stage mode, and the solvent is the volume ratio 4:1 DMF and DMSO) on the surface of the ITO film to control the coating thickness from 300nm to 10μm. The two gases used for spraying are both air, the angle formed by the air flow direction is 60°, and the total pressure is maintained at 1psi to 60psi. The coating amount was 0.25 mL/min. The perovskite coating film is then heat-treated at a temperature of 70° C. to 110° C. and a treatment time of 20 minutes to 30 minutes to obtain the perovskite film of Example 1. Then, the perovskite thin film was tested in the following evaluation manner.

Examples 2 to 4 and Comparative Examples 1 to 2

Examples 2 to 4 and Comparative Examples 1 to 2 were prepared in the same manner as in Example 1 to prepare perovskite thin films. The difference is that in Examples 2 to 4, the composition of the perovskite precursor solution, the conditions of the atomization step and the coating step are changed, and the specific conditions and evaluation results are shown in Table 1. In Comparative Example 1, the perovskite precursor solution was coated by spin coating, wherein the spin speed was 5000 rpm, the coating amount was 0.5 mL/min, and the working distance was 5 cm. In Comparative Example 2, a glass substrate was used instead of a crystalline silicon wafer, and a PEDOT:PSS layer was coated before spraying the perovskite precursor solution, wherein the coating solution was a PEDOT solution, and the coating condition was a rotation speed of 5000 rpm.

Evaluation method

1. Test of grain size and coverage

The experiment of grain size and coverage ratio is to measure the grain size and coverage ratio of the perovskite thin film with an electron microscope, wherein the detection conditions of the electron microscope are the conditions commonly used by those with ordinary knowledge in the technical field of the present invention.

2. Test of diffraction peak intensity ratio

The test of the diffraction peak intensity ratio is to use an X-ray diffractometer to measure the diffraction peak intensity ratio of the XRD pattern of the perovskite thin film in the (220) crystallographic direction and the (310) crystallographic direction, wherein the conditions are in the technical field of the present invention Conditions commonly used by persons with ordinary knowledge.

Table 1 Example comparative example 1 2 3 4 1 2 Process conditions Perovskite Precursor Solution Viscosity (cp) <30 <20 <15 <10 <30 <30 MAI/ _PbI2 Molecular weight (mole/g) >300000 >300000 100000~ 300000 ＜100000 >300000 >300000 DMF:DMSO Magnification (%) 0.5 0.5 2.0 5.0 0.5 0.5 MAI+ _PbI2 Total solid content (%) <15 <15 <10 <10 <15 <15 Substrate Crystalline silicon wafer Glass atomization step Droplet size (μm) <9 <5 <3 <2 spin coating <9 Coating steps Gas flow rate (mL/min) 0.1~30 0.1~30 0.1~20 0.1~10 0.1~30 Vibration frequency (kHz) 28 45 60 120 28 Coating area (mm×mm) >156×156 100×100 100×100 Coating thickness 300nm~10μm Evaluation results perovskite film grain size 2μm ~5μm 2μm ~5μm 2μm ~5μm 2μm ~5μm ＜2μm 400nm ~5μm Coverage (%) >80 >80 >80 >80 70~80 <70 Diffraction peak intensity ratio 1.8 - - - 1.2 1.0 Note: "The molecular weight of MAI/PbI ₂ " means the molecular weight of the polymer formed by MAI/PbI ₂ . "DMF:DMSO ratio" represents the volume ratio of DMF and DMSO. "Total solid content of MAI/PbI ₂ " means the total solid content of the polymer formed by MAI/PbI ₂ in the perovskite precursor solution, and it is measured by weight. "-" indicates that the measurement of the intensity of the diffraction peak and the calculation of the intensity ratio were not performed.

Please refer to Table 1, the coating area and coverage of each embodiment are larger than each comparative example, and the grain size of each embodiment is in the range of 2 μm to 5 μm. It can be seen that the manufacturing methods of the various embodiments can increase the area of the perovskite thin film and improve its uniformity.

Please refer to FIG. 6A to FIG. 6C , which are scanning electron micrographs of the perovskite thin films of Embodiment 1, Comparative Example 1 and Comparative Example 2, respectively. The appearance of the perovskite film in Example 1 is relatively smooth without holes, the film has good film-forming properties, the grain size is relatively uniform, and there is no crystal lattice accumulation, so the coverage rate is improved. In addition, the grain size of the perovskite thin film in Example 1 is slightly larger than that in Comparative Example 1, so the efficiency of the fabricated perovskite solar cell is improved. However, the perovskite thin films of Comparative Example 1 using spin coating and Comparative Example 2 using glass substrates are not uniform and have stacking phenomenon (shown by the white part).

Please refer to Figure 7, which is the XRD spectrum of the perovskite thin film of Embodiment 1, Comparative Example 1 and Comparative Example 2, the XRD spectrum of the perovskite thin film of Embodiment 1 is in the (220) crystal direction and the (310) crystal direction. The peak intensity ratio is 1.8, so the perovskite film has better absorption of visible light, and is more suitable for perovskite solar cells.

In summary, the manufacturing method of the perovskite thin film of the present invention is to use ultrasonic vibration to atomize the perovskite precursor solution into a plurality of liquid droplets with a specific particle size, and two gas streams with the sum of the pressure as the fixed value Spray these droplets on the substrate, thereby increasing the area of the perovskite film and improving its uniformity. The perovskite substrate containing the prepared perovskite thin film can be applied to perovskite solar cells to improve the performance of the perovskite solar cells.

Although the present invention has been disclosed above in terms of implementation, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field of the present invention can make various modifications and changes without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the appended patent application.

100: method 110,120: operation 111, 112, 113: steps 200: spraying device 210: Feed chute 220: Ultrasonic vibration element 230: spray port 240,250: gas nozzle θ: included angle 400: Perovskite substrate 410: Silicon substrate 420: Perovskite thin film 510: silicon substrate 522: electron transport layer 521: Perovskite Thin Films 523: Hole transport layer 530: electrode layer

In order to have a more complete understanding of the embodiments of the present invention and their advantages, please refer to the following descriptions together with the corresponding drawings. It must be emphasized that the various features are not drawn to scale and are for illustration purposes only. The contents of relevant diagrams are explained as follows: FIG. 1 is a flowchart illustrating a method for manufacturing a perovskite thin film according to an embodiment of the present invention. 2A and 2B are schematic diagrams showing the side and front structures of a spraying device according to an embodiment of the present invention, respectively. FIG. 3 is a diagram illustrating the pressure of two gases of a spraying device according to an embodiment of the present invention. FIG. 4 is a schematic diagram illustrating the structure of a perovskite substrate according to an embodiment of the present invention. 5A to 5C are schematic diagrams illustrating the structures of perovskite solar cells according to application examples of the present invention. FIGS. 6A to 6C are scanning electron micrographs of perovskite thin films according to Example 1, Comparative Example 1 and Comparative Example 2 of the present invention, respectively. FIG. 7 shows the XRD patterns of the perovskite thin films according to Example 1, Comparative Example 1 and Comparative Example 2 of the present invention.

100: method

110,120: operation

111, 112, 113: steps

Claims (8)

A method for manufacturing a perovskite thin film, comprising: performing a spray coating process on a silicon substrate to form a perovskite coating film on the silicon substrate, wherein the spray coating process comprises: providing a perovskite precursor solution ; performing an atomization step on the perovskite precursor solution to generate a plurality of droplets, wherein the atomization step is to atomize the perovskite precursor solution by means of an ultrasonic vibration; and performing a coating step to form the perovskite coating film, wherein the coating step is to use a gas to coat the droplets on the silicon substrate, the gas includes a first gas and a second gas, and the first gas A first gas flow direction of a gas forms an included angle with a second gas flow direction of the second gas, and the included angle is 20° to 160°; and performing a heat treatment on the perovskite coating film to obtain the perovskite A thin film, wherein the temperature of one of the heat treatments is not less than 60°C, and one of the perovskite thin films has an area greater than 22500mm ² . The method for manufacturing a perovskite thin film as claimed in claim 1, wherein when the spraying process comprises a single-stage spraying step, one of the perovskite precursors of the perovskite precursor solution comprises halide salts of group IVA elements and halide salts of alkylamines. The method for manufacturing a perovskite thin film as claimed in item 1, wherein when the spraying treatment includes a two-stage spraying step, the two-stage The formula spraying step comprises a first spraying step and a second spraying step, and one of the perovskite precursors of the perovskite precursor solution in the first spraying step comprises halide salts of group IVA elements and halide salts of alkylamines One of them, and a perovskite precursor of the perovskite precursor solution in the second spraying step includes the other of the halide salt of the IVA group element and the halide salt of the alkylamine. The method for manufacturing a perovskite thin film according to claim 1, wherein a particle size of the droplets is not greater than 10 μm. A perovskite substrate, comprising: a silicon substrate; and a perovskite thin film, wherein the perovskite thin film is prepared by the manufacturing method of the perovskite thin film as described in Claims 1 to 4, and is arranged on the On a silicon substrate; wherein the coverage of the perovskite film on one of the silicon substrates is greater than 75%, a grain size of the perovskite film is 2 μm to 5 μm, and an area of the perovskite film is greater than 22500 mm ² . The perovskite substrate according to claim 5, wherein the XRD pattern of the perovskite thin film has a diffraction peak intensity ratio between (220) crystallographic direction and (310) crystallographic direction greater than 1.2 and not greater than 1.8. A perovskite solar cell, comprising: a silicon substrate; a photoelectric conversion layer, comprising: a perovskite thin film, wherein the perovskite thin film utilizes the manufacturing method of the perovskite thin film as described in claims 1 to 4 Prepared, a grain size of the perovskite film is 2 μm to 5 μm, and an area of the perovskite film is greater than 22500 mm ² ; and an electron transport layer or a hole transport layer; and wherein when the photoelectric conversion layer When the perovskite film and the electron transport layer are included, the electron transport layer is disposed between the perovskite film and the silicon substrate, and the coverage of the perovskite film on the electron transport layer is greater than 75 %; or when the photoelectric conversion layer includes the perovskite thin film and the hole transport layer, the hole transport layer is arranged between the perovskite thin film and the electrode layer, and the perovskite thin film is opposite to the silicon A coverage of the substrate is greater than 75%; an electrode layer, wherein the photoelectric conversion layer is disposed between the silicon substrate and the electrode layer. The perovskite solar cell according to claim 7, wherein the XRD spectrum of the perovskite thin film has a diffraction peak intensity ratio between (220) crystallographic direction and (310) crystallographic direction greater than 1.2 and not greater than 1.8.

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