Solar cell and method of manufacturing the same and spraying device

Abstract

Solar cell, preparation method thereof and spraying device belong to the technical field of photovoltaics. When preparing perovskite cell containing multiple film layers on the surface of a textured silicon cell, the precursor solution of each film layer in the perovskite cell can be sprayed onto the surface to form the corresponding film layer by using the spraying method. In the spraying process, the droplets of the precursor solution are carried by the heated carrier gas for spraying, so that part of the first solvent in the droplets is volatilized by using the temperature of the carrier gas, and then the droplets with increased concentration are less likely to drop to the bottom of the pyramid surface after being sprayed onto the pyramid tip of the surface of the pre-textured surface, so that a certain amount of precursor droplets is retained at the tip of the pyramid, so as to form a film layer with a certain thickness at the tip of the surface after the subsequent solidification operation, thereby improving the safety and quality of the solar cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaics, in particular to a solar cell, a preparation method thereof and a spraying device. BACKGROUND

[0002] Solar energy, as a clean and renewable energy, is currently the most potential new energy on earth. The application of solar energy is mainly solar cells. As the fastest developing solar cell, the single-junction efficiency of perovskite solar cell has exceeded 25%, and the theoretical efficiency of perovskite silicon-based double-junction tandem cell based on perovskite has exceeded 45%. The laboratory efficiency has reached 31.3%, which has broad commercial application prospects.

[0003] The perovskite top cell in the tandem cell includes an intermediate composite layer, an electron transport layer (ETL), a perovskite absorption layer, a hole transport layer (HTL), a transparent conductive electrode (TCO), a metal electrode, and each functional layer as a modification or passivation. How to realize the shape-retaining deposition of several nanoscale thin films on the micron-level pyramid-shaped texture of the silicon substrate is a great challenge in the preparation of high-efficiency perovskite silicon tandem on the textured silicon heterojunction bottom cell.

[0004] These film layers can be prepared in various ways, including spin coating, vacuum evaporation, sputtering, atomic layer deposition, blade coating, slot coating, etc. In the process of preparing perovskite cells on textured silicon cells by solution method, it is easy to occur that the pyramid tips of the textured silicon cell cannot be covered with each film layer or the film layer is too thin, resulting in short circuit and the like. SUMMARY

[0005] The present application aims to provide a solar cell, a preparation method thereof and a spraying device to partially or completely improve the problem of too thin film layer thickness formed on the texture by coating in the related art.

[0006] In a first aspect, the embodiments of the present application provide a preparation method of a solar cell, comprising: forming a perovskite cell on a texture of a textured silicon cell. The method for forming the perovskite cell comprises: spraying a precursor solution to the texture to form a preset material layer. The precursor solution contains a preset material for forming the preset material layer and a first solvent. The spraying comprises: using a heated carrier gas to carry droplets of the precursor solution to spray the texture, so that part of the first solvent in the droplets volatilizes before the droplets contact the texture, increasing the concentration of the droplets sprayed to the texture.

[0007] The precursor solution of each film layer in the perovskite battery can be sprayed onto the surface to form the corresponding film layer. During the spraying process, when the heated carrier gas carries the droplets of the precursor solution, the temperature of the carrier gas causes part of the first solvent in the droplets to evaporate, thereby increasing the concentration of the droplets. After the droplets are sprayed onto the surface, the droplets sprayed onto the tip of the pyramid structure are less likely to fall to the bottom of the pyramid surface, so that a certain amount of precursor droplets can be retained at the tip of the pyramid to form a certain film layer at the tip of the pyramid after the subsequent solidification operation, thereby improving the safety and quality of the solar cell.

[0008] In combination with the first aspect, in optional embodiments of the present application, the method for forming the perovskite battery further includes: after the precursor solution is sprayed onto the surface to form the preset material layer, drying the preset material layer. Optionally, the preset material layer is blow-dried.

[0009] After the precursor solution is sprayed onto the surface to form the preset material layer, the preset material layer is blow-dried or dried in other ways, which can further remove the first solvent and other solvents in the preset material layer, thereby avoiding the formation of a second preset material layer on the first preset material layer which has not been dried, which can cause poor contact stability between the two preset material layers and affect the structural stability and conversion efficiency stability of the solar cell.

[0010] In combination with the first aspect, in optional embodiments of the present application, the boiling point of the first solvent is not higher than the temperature of the heated carrier gas. Optionally, the boiling point of the first solvent is not higher than 100°C. Optionally, the first solvent is selected from methanol, ethanol, isopropanol or acetonitrile.

[0011] The boiling point of the first solvent in the precursor solution is not higher than the temperature of the heated carrier gas, which can accelerate the evaporation speed of part of the first solvent in the droplet before the droplet contacts the surface, further increase the concentration of the droplet contacting the surface, and further increase the uniformity of the film thickness at the top and bottom of the surface.

[0012] In addition, the use of volatile first solvents such as methanol, ethanol, isopropanol or acetonitrile with a boiling point not higher than 100°C can not only accelerate the evaporation speed of the first solvent in the droplet, but also avoid the high temperature of the carrier gas affecting other film layers.

[0013] In combination with the first aspect, in optional embodiments of the present application, the carrier gas is mixed with an anti-solvent. Optionally, the anti-solvent is selected from at least one of toluene, chlorobenzene, anisole and diethyl ether.

[0014] The anti-solvent can be used to accelerate the separation rate of the solute and the first solvent in the droplet, and thus the volatilization effect of the first solvent in the droplet can be improved while the temperature of the carrier gas is appropriately reduced.

[0015] In combination with the first aspect, in an optional implementation of the present application, the texturing silicon cell includes a transparent conductive oxide film layer; the perovskite cell includes a tunneling composite layer, a hole transport material layer, a perovskite absorber layer, an electron transport material layer, and a transparent conductive material layer which are arranged in a stack. The method for forming the perovskite cell includes: using a spraying method to spray a first precursor solution of the tunneling composite material to the transparent conductive oxide film layer to form the tunneling composite layer; and then spraying a second precursor solution of the hole transport material, a third precursor solution of the perovskite absorber material, a fourth precursor solution of the electron transport material, and a third precursor solution of the transparent conductive material in sequence to form the hole transport material layer, the perovskite absorber layer, the electron transport material layer, and the transparent conductive material layer which are arranged in a stack on the tunneling composite layer.

[0016] The first precursor solution of the tunneling composite material is sprayed to the transparent conductive oxide film layer of the texturing silicon cell to form the tunneling composite layer, and then the hole transport material layer, the perovskite absorber layer, the electron transport material layer, and the transparent conductive material layer which are arranged in a stack are formed on the tunneling composite layer in sequence using the spraying method to obtain the texturing silicon cell-perovskite stacked cell.

[0017] In addition, each film layer of the perovskite cell is prepared using the spraying method, and the preparation of different film layers can be performed using the same or the same type of spraying equipment, thereby avoiding the use of different types of equipment for preparing different film layers and increasing the preparation cost and time of the solar cell.

[0018] In the second aspect, the embodiments of the present application provide a solar cell, which is prepared according to the preparation method of the solar cell provided in the first aspect; the solar cell includes a texturing silicon cell and a perovskite cell which are arranged in a stack.

[0019] Optionally, the texturing silicon cell includes a first TCO layer, an n-type amorphous silicon layer, a single crystal silicon layer, a p-type amorphous silicon layer, and a second TCO layer which are arranged in a stack.

[0020] Optionally, the perovskite cell includes a hole transport layer, a perovskite absorber layer, a passivation layer, an electron transport layer, a buffer layer, an IZO layer, and an anti-reflection layer which are arranged in a stack.

[0021] The thickness of each film layer of the perovskite cell formed on the textured surface of the texturing silicon cell is more uniform, thereby reducing the probability of short circuit of the solar cell due to uneven film layers, and making the solar cell have better safety.

[0022] In a third aspect, the embodiments of the present application provide a spraying device for implementing the preparation method of the solar cell of the first aspect, comprising a spraying mechanism and a moving mechanism. The spraying mechanism comprises a spray head, a first cavity and a carrier gas pipe. The first cavity has a first inlet, a second inlet and a first outlet. The output end of the spray head is connected with the first inlet to deliver the atomized liquid droplets into the first cavity. The carrier gas pipe is connected with the second inlet to carry the liquid droplets to be sprayed out of the first outlet. The carrier gas pipe is provided with a first heating member to heat the carrier gas. The moving mechanism is configured to move the spraying mechanism to spray the liquid droplets sprayed out of the first outlet to different positions of the textured surface.

[0023] In the preparation of the preset film layer, the precursor solution of the preset material is sent into the spray head, and the atomized liquid droplets of the precursor solution are sprayed out of the spray head. At the same time, the atomized liquid droplets are input into the first cavity from the first inlet. At this time, under the heating action of the first heating member, the heated carrier gas can be input into the first cavity from the second inlet by using the carrier gas pipe, and the atomized liquid droplets can be carried out of the first outlet of the first cavity by using the heated carrier gas, and sprayed onto the textured surface under the transportation of the carrier gas. Under the driving action of the moving mechanism, different positions of the textured surface can be sprayed in sequence to form a uniform coating on the textured surface.

[0024] Since the carrier gas has a certain temperature, the heated carrier gas can increase the volatilization speed of the first solvent in the liquid droplets during the spraying of the liquid droplets, thereby increasing the concentration of the liquid droplets, and then spraying the liquid droplets with high concentration to the textured surface. When the liquid droplets with high concentration after the volatilization of part of the first solvent are sprayed to the top and bottom of the tower, the liquid droplets at the top are not easy to flow to the bottom, thereby forming a film layer with a certain thickness at the top, and increasing the quality of the solar cell.

[0025] In combination with the third aspect, in an optional embodiment of the present application, the first inlet and the second inlet are heat-insulated from each other.

[0026] The heat insulation of the first inlet and the second inlet from each other can avoid the heating of the spray head at the first inlet by the carrier gas pipe at the second inlet with a higher temperature, thereby avoiding the premature volatilization of the first solvent in the solution in the spray head, which causes the liquid droplets sprayed out of the output end of the spray head to contain more solutes and block the output end of the spray head.

[0027] In combination with the third aspect, in an optional embodiment of the present application, the spraying device further comprises an air knife. The air knife is used to blow out gas to dry the preset material layer formed after spraying.

[0028] The wind knife is arranged in the spraying device, and the preset material layer formed after spraying can be dried by the air blown by the air duct, so that subsequent thin layers are formed on the dry thin layer, and the contact stability between adjacent thin layers is increased.

[0029] In combination with the third aspect, in optional embodiments of the present application, a plurality of spraying mechanisms are arranged at intervals along the movement direction of the movement mechanism. A wind knife is arranged between any two adjacent spraying mechanisms. The movement mechanism is configured to drive the spraying head mechanism and the wind knife to move synchronously, and the plurality of spraying mechanisms are configured to spray precursor solutions of different preset materials to simultaneously prepare a plurality of layers of the preset material. The air outlet of the wind knife is linear.

[0030] In combination with the third aspect, in optional embodiments of the present application, a plurality of spraying mechanisms are arranged at intervals along the movement direction of the movement mechanism. A wind knife is arranged between any two adjacent spraying mechanisms. The movement mechanism is configured to drive the spraying head mechanism and the wind knife to move synchronously, and the plurality of spraying mechanisms are configured to spray precursor solutions of different preset materials to simultaneously prepare a plurality of layers of the preset material. The air outlet of the wind knife is linear.

[0031] In combination with the third aspect, in optional embodiments of the present application, a plurality of spraying mechanisms are arranged at intervals along the movement direction of the movement mechanism. A wind knife is arranged between any two adjacent spraying mechanisms. The movement mechanism is configured to drive the spraying head mechanism and the wind knife to move synchronously, and the plurality of spraying mechanisms are configured to spray precursor solutions of different preset materials to simultaneously prepare a plurality of layers of the preset material. The air outlet of the wind knife is linear.

[0032] In combination with the third aspect, in optional embodiments of the present application, the spraying device further comprises a second heating member, and the second heating member is configured to heat the gas.

[0033] In combination with the third aspect, in optional embodiments of the present application, the spraying device further comprises a second heating member, and the second heating member is configured to heat the gas. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0035] Figure 1 Structure diagram of a solar cell provided for the examples of the present application;

[0036] Figure 2 Plan view diagram of a first spraying device provided for the examples of the present application;

[0037] Figure 3 Sectional view diagram of a spraying mechanism;

[0038] Figure 4 Plan view diagram of a second spraying device provided for the examples of the present application;

[0039] Figure 5 Spraying diagram of the second spraying device;

[0040] Figure 6 Sectional micrograph of a solar cell provided for Example 1 of the present application;

[0041] Figure 7 Sectional micrograph of a solar cell provided for Comparative Example 1 of the present application.

[0042] Legend: 200 - solar cell; 201 - monocrystalline silicon layer; 202 - n-type amorphous silicon layer; 203 - p-type amorphous silicon layer; 204 - first TCO layer; 205 - second TCO layer; 206 - hole transport layer; 207 - perovskite absorption layer; 208 - passivation layer; 209 - electron transport layer; 210 - buffer layer; 211 - IZO layer; 212 - anti-reflection layer; 213 - metal electrode;

[0043] 1 - spraying device; 10 - spraying mechanism; 101 - first spraying mechanism; 102 - second spraying mechanism; 11 - spray head; 12 - first cavity; 121 - first inlet; 122 - second inlet; 123 - first outlet; 13 - carrier gas pipe; 14 - first heating element; 20 - moving mechanism; 31 - air knife; 311 - first air knife; 312 - second air knife; 32 - second heating element; D1 - moving direction. DETAILED DESCRIPTION

[0044] Solar energy, as a clean and renewable energy, is currently the most potential new energy on earth. The application of solar energy is currently mainly solar cells. Among them, silicon heterojunction solar cells have a wide absorption spectrum and have been widely used. However, the silicon heterojunction cell has less absorption of high-energy spectrum, and the open-circuit voltage of the cell is not high, which needs to be further optimized. Perovskite solar cells, as a rapidly developing solar cell, have a single-junction efficiency of more than 25%. The theoretical efficiency of perovskite silicon-based double-junction stacked cells based on perovskite is more than 45%, and the laboratory efficiency has reached 31.3%, which has broad commercial application prospects.

[0045] The examples of the present application provide a solar cell 200 including a textured silicon cell and a perovskite cell to better utilize sunlight and improve the photoelectric conversion efficiency of the solar cell.

[0046] For example, in one possible embodiment, referring to Figure 1 The solar cell 200 includes a single crystal silicon layer 201, an n-type amorphous silicon layer 202, a p-type amorphous silicon layer 203, a first TCO layer 204, a second TCO layer 205, a hole transport layer 206, a perovskite absorption layer 207, a passivation layer 208, an electron transport layer 209, a buffer layer 210, an IZO layer 211, an anti-reflection layer 212, and a metal electrode 213.

[0047] However, in the preparation of the solar cell 200, the perovskite cell includes multiple layers of nanoscale thin films.

[0048] In some possible embodiments, the preparation of the film layer adopts a solution method, including spin coating, blade coating, etc.

[0049] However, the inventors have found that when the film layer is prepared on the textured surface by the solution method, the pyramid tips of the pyramid textured surface of the textured silicon heterojunction cell cannot be covered by the film layer or the film layer is too thin to cause short circuit, etc.

[0050] The inventors analyzed the reasons for the pyramid tips of the textured surface being unable to cover the film layer or the film layer being too thin and considered that, since the concentration of the precursor solution of each functional layer of the perovskite cell is low and the flowability is high, the precursor solution coated at the textured surface is prone to deposit at the bottom of the pyramid textured surface due to gravity, so that the coating solution at the top of the pyramid textured surface is less, and after subsequent drying, the coating at the top is prone to be too thin or there is no film layer.

[0051] The inventors tried to prepare the film layer by using a substrate heating type spraying method, that is, heating the substrate. However, the inventors have found that the substrate heating type spraying method has poor uniformity of film formation, and the atomized precursor solution has already crystallized before being attached to the substrate, which can cause poor bonding force between the thin films. Moreover, the temperature of the heated substrate rises, which can cause the first solvent at the position of the spray head to volatilize, increase the solute content in the droplets, and block the spray head, so that the thin film cannot be rapidly formed and the low-temperature preparation process cannot be realized.

[0052] Further, the inventors tried to prepare the film layer by using a non-solution method, such as thermal evaporation, electron beam evaporation, slot coating, blade coating, magnetron sputtering, atomic layer deposition, etc. to prepare each functional film layer of the perovskite. The inventors considered that, although the thermal evaporation, electron beam evaporation, slot coating, blade coating, magnetron sputtering, atomic layer deposition, etc. can realize the shape-preserving coverage of each functional layer of the perovskite on the pyramid textured surface, expensive and complex film preparation equipment needs to be used, which is not conducive to the preparation of the stacked cell.

[0053] Based on this, the application provides a preparation method of a solar cell, which simplifies the preparation process of different film layers of the solar cell 200 by using a spraying method, and improves the situation that the film layer is too thin or even non-existent at the top of the pyramid surface, thereby improving the safety and quality of the solar cell 200.

[0054] The preparation method of the solar cell 200 includes forming a perovskite cell on a textured surface of a textured silicon cell. The method of forming the perovskite cell includes spraying a precursor solution to the textured surface to form a preset material layer. The precursor solution contains a preset material for forming the preset material layer and a first solvent. The spraying includes using a heated carrier gas to carry droplets of the precursor solution to spray the textured surface, so that part of the first solvent in the droplets volatilizes before the droplets contact the textured surface, thereby increasing the concentration of the droplets sprayed to the textured surface.

[0055] For example, the textured silicon cell can be a heterojunction cell.

[0056] For example, the textured silicon cell can include a heterojunction cell, and a hole transport layer 206 disposed on a TCO layer of the heterojunction cell. Similarly, the textured silicon cell can include a heterojunction cell, and a hole transport layer 206 and a perovskite absorption layer 207 disposed on a TCO layer of the heterojunction cell.

[0057] That is, the textured silicon cell can include a heterojunction bottom cell, and one or more film layers in the perovskite cell formed on the heterojunction bottom cell.

[0058] When preparing a perovskite cell containing multiple film layers at the textured surface of a textured silicon cell, the precursor solution of each film layer in the perovskite cell can be sprayed to the textured surface to form the corresponding film layer by using a spraying method. Moreover, in the spraying process, when the heated carrier gas is used to carry the droplets of the precursor solution, the temperature of the carrier gas can cause part of the first solvent in the droplets to volatilize, thereby increasing the concentration of the droplets. After the droplets with increased concentration are sprayed to the textured surface, the droplets sprayed to the tip of the pyramid structure on the textured surface are less likely to drop to the bottom of the pyramid textured surface, so that a certain amount of precursor droplets can be retained at the tip of the pyramid, so as to form a film layer with a certain thickness at the tip of the pyramid textured surface after the subsequent solidification operation, thereby improving the safety and quality of the solar cell 200.

[0059] For example, the first precursor solution of the tunneling composite material is sprayed onto the textured surface of the silicon heterojunction cell to form a tunneling composite material layer; then the second precursor solution of the hole transport material is sprayed onto the surface of the tunneling composite layer to form a hole transport material layer; then the third precursor solution of the perovskite absorber material is sprayed onto the surface of the hole transport material layer to form a perovskite absorber material; then the fourth precursor solution of the electron transport material is sprayed onto the surface of the perovskite absorber material to form an electron transport material layer; and then the third precursor solution of the transparent conductive material is sprayed onto the surface of the electron transport material layer to form a transparent conductive material layer.

[0060] For example, in the perovskite / silicon heterojunction stacked cell, the tunneling composite material layer can be formed on the first TCO layer 204 by using the spraying method provided in the present example, and then other film layer structures can be formed on the tunneling composite material layer by using other film forming methods such as thermal evaporation, electron beam evaporation, slot coating, blade coating, magnetron sputtering, and atomic layer deposition.

[0061] Similarly, any one or more of the film layer structures of the perovskite cell can be prepared by using the spraying method provided in the present example. The present application does not limit which film layer or which film layers of the perovskite cell are prepared by using the spraying method provided in the present example.

[0062] The present application does not limit the specific form of the precursor solution. In some possible embodiments, the precursor solution can be a suspension.

[0063] Further, the sprayed coating can be dried by baking or blowing dry, etc. to facilitate the preparation of other film layers on the dried film layer and to increase the bonding stability between the film layers.

[0064] Further, in order to accelerate the volatilization rate of part of the first solvent in the droplet during the carrying process of the carrier gas, in one possible embodiment, the boiling point of the first solvent is not higher than the temperature of the heated carrier gas.

[0065] Further, by using the first solvent which is easy to volatilize, the volatilization rate of part of the first solvent in the droplet can be increased while appropriately reducing the temperature of the carrier gas.

[0066] For example, the heating temperature of the carrier gas is not higher than 100°C, which can further reduce the adverse effects of the heated carrier gas on other film layers in the cell structure.

[0067] At this time, the first solvent of the precursor solution can be selected from a solution with a boiling point not higher than 100°C.

[0068] For example, the first solvent is selected from methanol, ethanol, isopropanol, and or acetonitrile.

[0069] To further properly reduce the temperature of the carrier gas and increase the volatilization rate of the first solvent in the droplet, in one possible embodiment, an anti-solvent can be mixed into the carrier gas.

[0070] When the carrier gas carries the atomized droplet, the droplet will contact the anti-solvent in the carrier gas, thereby accelerating the separation rate of the first solvent and the solute.

[0071] Illustratively, the anti-solvent is selected from at least one of toluene, chlorobenzene, anisole, and diethyl ether.

[0072] Further, to facilitate the preparation of the corresponding film layer by the spraying method, the embodiments of the present application also provide a spraying device 1.

[0073] Please refer to Figure 2 and Figure 3 , the spraying device 1 comprises a spraying mechanism 10 and a moving mechanism 20. The spraying mechanism 10 comprises a spray head 11, a first cavity 12, and a carrier gas pipe 13. The first cavity 12 has a first inlet 121, a second inlet 122, and a first outlet 123. The output end of the spray head 11 is connected to the first inlet 121 to transport the atomized droplet into the first cavity 12. The carrier gas pipe 13 is connected to the second inlet 122 to carry the droplet out of the first outlet 123. The carrier gas pipe 13 is provided with a first heating element 14 to heat the carrier gas. The moving mechanism 20 is configured to move the spraying mechanism 10 to spray the droplet sprayed out of the first outlet 123 to different positions on the pile surface.

[0074] In the preparation of the preset film layer by the spraying device 1 provided by the present example, the precursor solution of the preset material is input into the spray head 11, the atomized droplet of the precursor solution is sprayed out of the spray head 11, and the atomized droplet is input into the first cavity 12 from the first inlet 121. At this time, under the heating action of the first heating element 14, the heated carrier gas can be input into the first cavity 12 from the second inlet 122 by the carrier gas pipe 13, the atomized droplet is carried out of the first outlet 123 of the first cavity 12 by the heated carrier gas, and is sprayed onto the pile surface under the transportation of the carrier gas. Under the driving action of the moving mechanism 20, different positions on the pile surface can be sprayed in sequence to form a uniform coating on the pile surface.

[0075] The present application does not limit the specific form of the spraying mechanism 10, and relevant personnel can make corresponding adjustments as needed under the condition of transporting the precursor droplet to the pile surface for spraying by the heated carrier gas.

[0076] In one possible embodiment, the spray head 11 can be selected from an ultrasonic atomizing nozzle. In the atomization process of the ultrasonic atomizing nozzle, the atomized droplet size can be adjusted by the vibration frequency of the nozzle without relying on pressure.

[0077] Further, in order to facilitate the carrier gas to carry the liquid droplets to spray to the surface, in a possible embodiment, please continue to refer to Figure 3 The second inlet 122 is located at the top of the first cavity 12, and the first outlet 123 is located at the bottom of the first cavity 12, so as to form a spraying layer on the surface of the battery piece placed below the first cavity 12.

[0078] Further, the heat insulation material can be arranged between the first inlet 121 and the second inlet 122, so that the first inlet 121 and the second inlet 122 are insulated from each other, and the higher-temperature carrier gas pipe 13 at the second inlet 122 can avoid heating the spray head 11 at the first inlet 121, thereby avoiding the first solvent in the solution in the spray head 11 from evaporating too early, and causing the liquid droplets sprayed from the output end of the spray head 11 to contain more solute and block the output end of the spray head 11.

[0079] The moving mechanism 20 is configured to drive the spraying mechanism 10 to move, so as to spray the liquid droplets sprayed from the first outlet 123 to different positions of the surface.

[0080] The present application does not limit the specific arrangement of the moving mechanism 20, and the relevant personnel can make corresponding selection according to the needs.

[0081] In a possible embodiment, the moving mechanism 20 is a pneumatic cylinder. The first cavity 12 in the spraying mechanism 10 is connected with the movable end of the pneumatic cylinder, and the carrier gas pipe 13 and the spray head 11 are connected with the first cavity 12.

[0082] Alternatively, the moving mechanism 20 can be a lead screw nut structure. The lead screw is connected with the motor through a shaft coupling, the guide rod is arranged in parallel with the lead screw, and the nut matched with the lead screw is arranged at the moving frame, and the moving frame is slidably connected with the guide rod. When the motor drives the lead screw to rotate, the nut moves along the axial direction of the lead screw under the fixing action of the moving frame, thereby driving the moving frame to move along the axial direction of the lead screw. The first cavity 12 in the spraying mechanism 10 is connected with the moving frame, and the carrier gas pipe 13 and the spray head 11 are connected with the first cavity 12.

[0083] Further, in order to facilitate the blowing and drying of the sprayed coating, the spraying device 1 is further provided with an air knife 31.

[0084] Further, the second heating element 32 can be arranged at the air knife 31, so as to increase the temperature of the air blown by the air knife 31. The blowing and drying speed of the coating can be increased under the condition that the air speed of the air knife 31 is appropriately reduced. For example, the heating temperature of the second heating element 32 is 40-50°C.

[0085] The second heating element 32 can be a resistance heating wire, or a hot water pipe can be embedded in the air knife 31.

[0086] Further, the spraying mechanism 10 and the air knife 31 can be moved simultaneously by the moving mechanism 20, and the air knife 31 is arranged at the rear end of the spraying mechanism 10 to dry the coating layer formed by the spraying mechanism 10.

[0087] For example, a plurality of spraying mechanisms 10 are arranged at intervals along the moving direction D1 at the moving end of the moving mechanism 20, and an air knife 31 is arranged between each two adjacent spraying mechanisms 10.

[0088] The air knife 31 is arranged at a distance from the spraying mechanism 10 to reduce the influence of the air blown by the air knife 31 on the spraying process of the spraying mechanism 10 at the front end or the rear end of the air knife 31.

[0089] By using a plurality of spraying mechanisms 10 and air knives 31, the plurality of spraying mechanisms 10 can simultaneously spray different coating layers during the movement of the moving mechanism 20, and thus a plurality of coating layers can be formed simultaneously during the movement of the moving mechanism 20.

[0090] For example, please continue to refer to Figure 2 The distance between the air knife 31 and the spraying mechanism 10 can be adjusted to be greater than the length of the battery along the moving direction D1. When the spraying device 1 provided in the example is used for spraying, a plurality of batteries to be sprayed can be arranged at intervals along the moving direction D1. First, the first spraying mechanism 10 sprays the first coating layer on the first battery. Under the action of the moving mechanism 20, the first spraying mechanism 10 gradually moves to the surface of the second battery and continues to spray the first coating layer on the second battery. At this time, the first air knife 31 at the rear end of the first spraying mechanism 10 moves above the first battery to dry the first coating layer on the first battery to form the first film layer. In this way, as the moving mechanism 20 moves, the plurality of spraying mechanisms 10 and air knives 31 gradually form different film layers on the plurality of batteries in sequence.

[0091] Further, the air port of the air knife 31 can be linear. The linear air port can dry the corresponding coating layer in a line scanning manner, reducing the influence of the air volume of the air knife 31 on the spraying quality of the spraying mechanism 10 at the rear end or the front end.

[0092] Further, the temperature of each second heating element 32 arranged on the air knife 31 can be adjusted individually to adjust the temperature of each air knife 31 individually.

[0093] Alternatively, please refer to Figure 4 The plurality of spraying mechanisms 10 simultaneously spray different film layers on the same battery. Figure 4In the drawings, only 3 groups of spraying mechanisms 10 are drawn for the purpose of illustration, and it is not intended to limit the spraying device 1 to only 3 groups of spraying mechanisms. The specific number of spraying mechanisms 10 in the spraying device 1 can be selected according to the number of layers of films to be prepared.

[0094] Referring to Figure 5 When the spraying device 1 provided by the present example is used for spraying, different precursor solutions of different materials can be input into different spraying mechanisms 10. According to the order of the coating layers from inside to surface, the corresponding precursor solutions are input into different spraying mechanisms 10 in sequence from front to back along the moving direction D1. Then, after the first spraying mechanism 101 at the front end sprays at the first position of the textured surface, the first air knife 311 at the rear end of the spraying mechanism 10 moves above the first position to dry the first position. Then, the first air knife 311 continues to move forward, so that the second spraying mechanism 102 at the rear end of the first air knife 311 sprays on the first film layer at the first position, and a second film layer is formed on the first film layer at the first position through the drying of the second air knife 312 at the rear end. In this way, different layers of films of different materials are gradually formed on the textured surface of the silicon heterojunction cell through the movement of the moving mechanism 20, so as to increase the preparation efficiency of the perovskite cell.

[0095] For the purpose of illustration, Figure 5 In the drawings, only 5 groups of spraying mechanisms 10 are drawn to prepare 5 different layers of films, Figure 5 and it is not intended to limit the spraying device 1 to only 5 groups of spraying mechanisms. The specific number of spraying mechanisms 10 in the spraying device 1 can be selected according to the number of layers of films to be prepared.

[0096] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0097] Embodiment 1

[0098] Embodiment 1 provides a solar cell prepared by the following method:

[0099] Using the spraying device 1 provided by the present application, the precursor solutions for preparing the hole transport layer, the perovskite layer, the LiF layer, the C60 layer and the SnO2 layer are input into the different spraying mechanisms 10 of the spraying device 1 in sequence.

[0100] In the drawings, only 3 groups of spraying mechanisms 10 are drawn for the purpose of illustration, and it is not intended to limit the spraying device 1 to only 3 groups of spraying mechanisms. The specific number of spraying mechanisms 10 in the spraying device 1 can be selected according to the number of layers of films to be prepared. The perovskite layer adopts a three-cation system Csx (FA 1-x-y MA y 0.95Pb(I 1-x-y Br x+y 3. When dissolving in DMF, a small amount of ethanol is added to accelerate solvent evaporation. The solution concentration is 0.8-1.8 mol / ml, and the temperature of the air knife 31 is about 60℃. When using the spraying method, 2-thiophene ethylamine bromide (TEABr) is used instead of LiF. It is dissolved in isopropanol (IPA) at a concentration of 0.8-2.0 mg / ml, and the temperature of the air knife 31 is about 50℃. When preparing the C60 layer, C60 is dissolved in chlorobenzene. Ethanol is added to accelerate evaporation. The concentration is 0.8-2.0 mg / ml, and the temperature of the air knife 31 is about 60℃. When preparing SnO2, commercial SnO2 (15%) aqueous colloidal solution is used. It is dissolved in a mixed solvent of water and ethanol at a concentration of 1.5%-5%, and the temperature of the air knife 31 is about 50℃.

[0101] A hole transport layer, a perovskite layer, a LiF layer, a C60 layer, and a SnO2 layer are sequentially sprayed onto a heterojunction bottom cell using a spraying device 1.

[0102] Observe the microstructure images of each film layer of the solar cell provided in Example 1, such as Figure 6 As shown.

[0103] Comparative Example 1

[0104] Comparative Example 1 provides a solar cell that differs from Example 1 in that:

[0105] Using the spraying apparatus 1 provided in this application, precursor solutions for preparing hole transport layers, perovskite layers, LiF layers, C60 layers, and SnO2 layers are input into different spraying mechanisms 10 of the spraying apparatus 1. The first heating element 14 at each spraying mechanism 10 is in a closed state, ensuring that the carrier gas temperature is room temperature.

[0106] The hole transport layer material is 2PACz with a concentration of 0.5-1.5 mg / ml, dissolved in ethanol for spraying, and the temperature of the air knife 31 is approximately 40°C; the perovskite layer uses a tricationic system Cs. x (FA 1-x-y MA y 0.95Pb(I 1-x-y Br x+y)3, dissolved in DMF, without adding ethanol, the solution concentration is 0.8-1.8 mol / ml, the temperature of the air knife 31 is about 60°C; when using the spraying method, LiF is replaced by 2-thiophene ethylamine bromide salt (TEABr), dissolved in isopropyl alcohol (IPA), the concentration is 0.8-2.0 mg / ml, the temperature of the air knife 31 is about 50°C; when preparing the C60 layer, C60 is dissolved in chlorobenzene, without adding ethanol, the concentration is 0.8-2.0 mg / ml, the temperature of the air knife 31 is about 60°C; when preparing SnO2, SnO2 uses a commercial SnO2 (15%) hydrogel solution, dissolved in water, the concentration is 1.5%-5%, the temperature of the air knife 31 is about 50°C.

[0107] The micro-morphology of each film layer of the solar cell provided by Comparative Example 1 is observed, as shown in Figure 7 .

[0108] Result analysis: by comparing Figure 6 and Figure 7 , it can be seen that the thickness of each film layer in the solar cell provided by Example 1 is uniform, and the film layer thickness at the top of the tower is relatively uniform with the film layer thickness at the bottom of the tower. In the film layer provided by Comparative Example 1, the film layer at the top of the textured structure is thinner; the film layer thickness at the bottom is thicker, about twice the film layer thickness at the top.

[0109] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing a solar cell, characterized by, The application relates to a method for forming a perovskite cell on a textured surface of a textured silicon cell. The method comprises: spraying a precursor solution to the textured surface to form a preset material layer; the precursor solution contains a preset material and a first solvent for forming the preset material layer. The spraying comprises: using a heated carrier gas to carry droplets of the precursor solution to spray the textured surface, so that part of the first solvent in the droplets volatilizes before the droplets contact the textured surface, and the concentration of the droplets sprayed to the textured surface is increased. The boiling point of the first solvent is not higher than the temperature of the heated carrier gas. The method further comprises:

2. The method for producing a solar cell according to claim 1, wherein After spraying the precursor solution to the textured surface to form the preset material layer, the preset material layer is dried. The preset material layer is dried by blowing.

3. The method for producing a solar cell according to claim 2, wherein The boiling point of the first solvent is not higher than 100 DEG C.

4. The method for manufacturing a solar cell according to claim 1, wherein The first solvent is selected from methanol, ethanol, isopropanol or acetonitrile.

5. The method for producing a solar cell according to claim 4, wherein The carrier gas is mixed with an anti-solvent.

6. The method for manufacturing a solar cell according to claim 1, wherein The anti-solvent is selected from at least one of toluene, chlorobenzene, anisole and diethyl ether.

7. The method for manufacturing a solar cell according to claim 6, wherein The textured silicon cell comprises a transparent conductive oxide film layer; the perovskite cell comprises a tunneling composite layer, a hole transport material layer, a perovskite absorbing material layer, an electron transport material layer and a transparent conductive material layer which are arranged in a stack.

8. The method of producing a solar cell according to any one of claims 1 to 7, characterized in that, The method comprises: using the spraying method to spray a first precursor solution of a tunneling composite material to the transparent conductive oxide film layer to form the tunneling composite layer. Then, a second precursor solution of a hole transport material, a third precursor solution of a perovskite absorbing material, a fourth precursor solution of an electron transport material and a third precursor solution of a transparent conductive material are sprayed in sequence to form the hole transport material layer, the perovskite absorbing material layer, the electron transport material layer and the transparent conductive material layer which are arranged in a stack on the tunneling composite layer. The solar cell is prepared by the method according to any one of claims 1-8; the solar cell comprises a textured silicon cell and a perovskite cell which are arranged in a stack.

9. A solar cell, characterized by The textured silicon cell comprises a first TCO layer, an n-type amorphous silicon layer, a single crystal silicon layer, a p-type amorphous silicon layer and a second TCO layer which are arranged in a stack.

10. The solar cell according to claim 9, characterized in that, The perovskite cell comprises a hole transport layer, a perovskite absorbing layer, a passivation layer, an electron transport layer, a buffer layer, an IZO layer and an anti-reflection layer which are arranged in a stack.

11. The solar cell according to claim 9, characterized in that, The application relates to a spraying mechanism.

12. A spray device for carrying out the method of producing a solar cell according to any one of claims 1 to 8, characterized in that The spraying mechanism comprises a nozzle, a first cavity and a carrier gas pipe. The first cavity has a first inlet, a second inlet and a first outlet. The output end of the nozzle is connected with the first inlet to convey atomized droplets into the first cavity. The carrier gas pipe is connected with the second inlet to carry the droplets to be sprayed out of the first outlet; the carrier gas pipe is provided with a first heating member to heat the carrier gas. A moving mechanism is arranged to drive the spraying mechanism to move so that the droplets sprayed out of the first outlet are sprayed to different positions of the textured surface. The first inlet and the second inlet are heat-insulated from each other. ​ 13. The spray device of claim 12, wherein, ​ 14. The spray device of claim 12, wherein, The spraying device further comprises an air knife; the air knife is used for blowing gas to dry the preset material layer formed after spraying.

15. The spray device of claim 14, wherein, A plurality of spraying mechanisms are arranged at intervals along the moving direction of the moving mechanism; the air knife is arranged between two adjacent spraying mechanisms; the moving mechanism is configured to drive the spraying head mechanism and the air knife to move synchronously, and the plurality of spraying mechanisms are configured to spray the precursor solution of different preset materials to simultaneously prepare a plurality of preset material layers. The air port of the air knife is linear.

16. The spray device of claim 14, wherein, The spraying device further comprises a second heating member configured to heat the gas.

Images