Perovskite thin film preparation device

Abstract

The present invention relates to the technical field of solar cell production, and specifically relates to a perovskite thin film preparation device, which includes a perovskite coating adjustment device, an anti-solvent coating adjustment device, and a substrate transfer mechanism. The perovskite coating adjustment device and the anti-solvent coating adjustment device are both arranged above the substrate transfer mechanism. The perovskite coating adjustment device includes a first adjustment vehicle, a first flow control valve, and a perovskite coating element, and the perovskite coating element is arranged on the first adjustment vehicle in a liftable manner and the flow rate is controlled by the first flow control valve. The anti-solvent coating adjustment device includes a second adjustment vehicle, a second flow control valve, and an anti-solvent coating element, and the anti-solvent coating element is arranged on the second adjustment vehicle in a liftable manner and the flow rate is controlled by the second flow control valve. The present invention directly adopts an anti-solvent post-treatment method after wet film scraping to prepare a perovskite thin film, and can realize the preparation of a large-area, uniform and pinhole-free perovskite thin film at low temperature.

Description

Technical Field

[0001] The present invention relates to the field of solar cell preparation, and more particularly to a perovskite thin film preparation device. Background Art

[0002] In recent years, perovskite solar cells have received great attention due to their advantages such as low preparation cost, high efficiency, adjustable bandgap, and high absorption coefficient. In just a few years, the photoelectric conversion efficiency has increased from 3.8% to 23.7%. While perovskite solar cells have become a research hotspot in the field of photovoltaic devices, they have also attracted many companies to realize the industrialization of perovskite solar cells.

[0003] Currently, perovskite solar cells have problems such as poor stability and large-area preparation technology. In the prior art, the technology for high-efficiency preparation in the laboratory usually adopts the spin coating method, but this method cannot meet the requirements of industrialization. In order to further improve the efficiency of industrialization and reduce costs, many large-area preparation technologies have been proposed, among which the blade coating and slot die coating methods have received more attention. The conventional methods for preparing perovskite by blade coating and slot die coating include two ways: preparation on a hot stage at high temperature and film formation assisted by nitrogen blowing. The advantage of these two methods is high integration and suitability for the requirements of the production line. However, the hot stage method at high temperature has limitations in the production of flexible substrates, and its preparation temperature is usually above 140°C, so low-cost low-melting-point polymers such as PET cannot be used. The method of film formation assisted by nitrogen blowing meets the requirements of low-temperature preparation, but due to continuous blowing, it is difficult to realize production in a glove box. Summary of the Invention

[0004] The purpose of the present invention is to provide a perovskite thin film preparation device, which directly adopts the method of anti-solvent post-treatment after wet film blade coating to prepare perovskite thin films, without the need for a hot stage at high temperature or nitrogen assistance, and can ensure the preparation of perovskite thin films at low temperature. Only subsequent annealing treatment is required, and large-area, uniform and pinhole-free perovskite thin films can be prepared at low temperature.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A perovskite thin film preparation device includes a perovskite coating adjustment device, an anti-solvent coating adjustment device, and a substrate transfer mechanism. The perovskite coating adjustment device and the anti-solvent coating adjustment device are both arranged above the substrate transfer mechanism. The perovskite coating adjustment device includes a first adjustment vehicle, a first flow control valve, and a perovskite coating element, and the perovskite coating element is arranged on the first adjustment vehicle in a liftable manner and controls the flow rate through the first flow control valve. The anti-solvent coating adjustment device includes a second adjustment vehicle, a second flow control valve, and an anti-solvent coating element, and the anti-solvent coating element is arranged on the second adjustment vehicle in a liftable manner and controls the flow rate through the second flow control valve. The first adjustment vehicle and the second adjustment vehicle both travel along the track.

[0007] The first adjustment vehicle is provided with a first motor, and the second adjustment vehicle is provided with a second motor. Gears are provided on the output shafts of the first motor and the second motor. A rack is provided on the side wall of the track, and each gear meshes with the rack.

[0008] The first adjustment vehicle is provided with a first lifting device, and the perovskite coating element is driven to lift through the first lifting device. The second adjustment vehicle is provided with a second lifting device, and the anti-solvent coating element is driven to lift through the second lifting device.

[0009] The perovskite coating element is connected to a perovskite liquid storage tank through a first pipeline, and a first flow control valve is provided on the first pipeline. The anti-solvent coating element is connected to an anti-solvent storage tank through a second pipeline, and a second flow control valve is provided on the second pipeline.

[0010] The substrate first passes through the perovskite coating element to coat a layer of perovskite wet film, and passes through the anti-solvent coating element when the perovskite wet film is not dry.

[0011] The advantages and positive effects of the present invention are as follows:

[0012] 1. The present invention directly uses an anti-solvent post-treatment method to prepare a perovskite film after the perovskite wet film is scrape-coated, without the need for a high-temperature hot stage or nitrogen assistance, and can ensure the preparation of a perovskite film at low temperature. Only subsequent annealing treatment is required, and a large-area, uniform and pinhole-free perovskite film can be prepared at low temperature.

[0013] 2. The present invention needs to ensure that the anti-solvent wet film is coated before the perovskite wet film dries. Therefore, it is necessary to precisely adjust the positions and coating speeds of the perovskite coating element and the anti-solvent coating element. The present invention adjusts the distance between the perovskite coating element and the substrate through the first lifting device in the perovskite coating adjustment device, adjusts the distance between the anti-solvent coating element and the rigid substrate through the second lifting device in the anti-solvent coating adjustment device, and adjusts the distance between the perovskite coating element and the anti-solvent coating element by controlling the movement of the first adjustment vehicle in the perovskite coating adjustment device and the second adjustment vehicle in the anti-solvent coating adjustment device. Then, the perovskite coating flow is controlled by the first flow control valve, and the anti-solvent coating flow is controlled by the second flow control valve, so as to achieve the purpose of coating the anti-solvent at the optimal time node and improve the film-forming quality.

[0014] 3. The present invention uses a gear-rack assembly to transmit the motor torque of each adjustment vehicle. The gear-rack assembly can ensure precise control of the moving position of the adjustment vehicle, and thus achieve precise adjustment of the distance between the perovskite coating element and the anti-solvent coating element.

[0015] 4. The present invention can be applied to both rigid substrates and flexible substrates, which is conducive to popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagrams of the anti-solvent coating film adjusting device and the perovskite coating film adjusting device of the present invention.

[0017] Figure 2 Schematic diagram of the preparation when the present invention coats a rigid substrate.

[0018] Figure 3 Schematic diagram of the preparation when the present invention coats a flexible substrate.

[0019] Among them, 1 is a perovskite coating film element, 101 is a first adjusting vehicle, 102 is a first motor, 103 is a first lifting device, 104 is a first pipeline, 105 is a first flow control valve, 2 is an anti-solvent coating film element, 201 is a second adjusting vehicle, 202 is a second motor, 203 is a second lifting device, 204 is a second pipeline, 205 is a second flow control valve, 3 is an anti-solvent wet film, 4 is a perovskite wet film, 5 is a rigid substrate, 6 is a perovskite film after annealing, 7 is a flexible substrate, 8 is a heating table, 9 is a track, 10 is a feeding reel, 11 is a turning roller, and 12 is a winding reel. DETAILED DESCRIPTION OF THE INVENTION

[0020] As Figures 1 to 3 shown, the present invention includes a perovskite coating film adjusting device, an anti-solvent coating film adjusting device, and a substrate transmission mechanism. The perovskite coating film adjusting device and the anti-solvent coating film adjusting device are both arranged above the substrate transmission mechanism. The perovskite coating film adjusting device includes a first adjusting vehicle 101, a first flow control valve 105, and a perovskite coating film element 1. The perovskite coating film element 1 is liftably arranged on the first adjusting vehicle 101 and the flow rate is controlled by the first flow control valve 105. The anti-solvent coating film adjusting device includes a second adjusting vehicle 201, a second flow control valve 205, and an anti-solvent coating film element 2. The anti-solvent coating film element 2 is liftably arranged on the second adjusting vehicle 201 and the flow rate is controlled by the second flow control valve 205. The first adjusting vehicle 101 and the second adjusting vehicle 201 both travel along the track 9. The perovskite coating film element 1 and the anti-solvent coating film element 2 can be a doctor blade or a coating head, which is well-known technology in this field. The first flow control valve 105 and the second flow control valve 205 are well-known technology in this field and are commercially available products.

[0021] As Figure 1As shown in the figure, a first motor 102 is provided inside the first adjustment vehicle 101, and a second motor 202 is provided inside the second adjustment vehicle 201. Gears are provided on the output shafts of the first motor 102 and the second motor 202. A rack is provided on the side wall of the track 9, and each gear meshes with the rack. When the first motor 102 and the second motor 202 are started, they respectively drive the corresponding gears to rotate, thereby driving the movement of the adjustment vehicle body.

[0022] As Figure 1 shown in the figure, a first lifting device 103 is provided inside the first adjustment vehicle 101, and the perovskite coating element 1 is driven to lift by the first lifting device 103. A second lifting device 203 is provided inside the second adjustment vehicle 201, and the anti-solvent coating element 2 is driven to lift by the second lifting device 203. In this embodiment, both the first lifting device 103 and the second lifting device 203 are cylinders.

[0023] As Figure 1 shown in the figure, the perovskite coating element 1 is connected to the perovskite liquid storage tank through a first pipeline 104, and a first flow control valve 105 is provided on the first pipeline 104. The anti-solvent coating element 2 is connected to the anti-solvent storage tank through a second pipeline 204, and a second flow control valve 205 is provided on the second pipeline 204. In this embodiment, the first pipeline 104 and the second pipeline 204 are flexible hoses, which can move with the vehicle and will not affect the adjustment of the position of the adjustment vehicle.

[0024] The present invention can be applied to different substrates, and the substrate transfer mechanisms for transporting different substrates are different.

[0025] Embodiment 1

[0026] This embodiment is directed to a rigid substrate 5. The substrate transfer mechanism in this embodiment can adopt a conventional conveyor belt transfer mechanism, which includes a conveyor belt and conveyor rollers provided at both ends of the conveyor belt. Any one of the conveyor rollers is driven to rotate by a motor, thereby driving the conveyor belt to move. The rigid substrate 5 is placed on the conveyor belt.

[0027] The specific preparation process of this embodiment is as follows:

[0028] First, substrate preparation is carried out. The rigid substrate 5 can be transparent conductive glass or a metal plate. The prepared rigid substrate 5 is cleaned by a standard process. The cleaning process can use ethanol, isopropanol, etc. For large-area preparation, a neutral cleaning solution can be used for cleaning to ensure the cleanliness of the rigid substrate 5. The cleaning process is a well-known technology in the art. Then, functional layers such as an electrode layer are prepared on the rigid substrate 5. The deposition of metal electrodes or metal oxides can be completed by processes such as sputtering and thermal evaporation. This is a well-known technology in the art. Then, the prepared rigid substrate 5 is input into the present invention for the preparation of the perovskite film.

[0029] As Figure 2 shown, when the rigid substrate 5 is being transported, it first passes under the perovskite coating element 1 and a layer of perovskite wet film 4 is coated, and then passes under the anti-solvent coating element 2, and another layer of anti-solvent wet film 3 is coated on the perovskite wet film 4.

[0030] The present invention requires a layer of anti-solvent wet film 3 to be quickly coated before the perovskite wet film 4 dries to form a high-quality perovskite film. However, it is difficult to grasp the time node for anti-solvent coating. Therefore, the present invention is provided with a perovskite coating adjustment device and an anti-solvent coating adjustment device to determine the optimal positions and the optimal output flow rates of the perovskite coating element 1 and the solvent coating element 2, so as to improve the film-forming quality.

[0031] Among them, the first lifting device 103 in the perovskite coating adjustment device is used to adjust the distance between the perovskite coating element 1 and the rigid substrate 5, and the second lifting device 203 in the anti-solvent coating adjustment device is used to adjust the distance between the anti-solvent coating element 2 and the rigid substrate 5. And by controlling the movement of the first adjustment vehicle 101 in the perovskite coating adjustment device and the movement of the second adjustment vehicle 201 in the anti-solvent coating adjustment device, the distance between the perovskite coating element 1 and the anti-solvent coating element 2 is adjusted. Moreover, the present invention uses a gear-rack assembly to transmit the motor torque of each adjustment vehicle. The gear-rack assembly can ensure precise control of the movement position of the adjustment vehicle, and thus achieve precise adjustment of the distance between the perovskite coating element 1 and the anti-solvent coating element 2. After the positions of the perovskite coating element 1 and the anti-solvent coating element 2 are determined, the perovskite coating element 1 controls the perovskite coating flow rate through the first flow control valve 105, and the anti-solvent coating element 2 controls the anti-solvent coating flow rate through the second flow control valve 205.

[0032] After the anti-solvent is scrape-coated on the perovskite film 4, the anti-solvent and the solvent need to be quickly removed to promote the crystallization and crystal growth of the perovskite thin film. Therefore, as Figure 2 shown, in this embodiment, the prepared film is sent into a heating table 8 to achieve solvent volatilization. The heating temperature of the heating table 8 is controllable to keep the temperature constant. The heating table 8 is a well-known technology in the art and is a commercially available product. After annealing, the perovskite film 6 adheres to the rigid substrate 5. The present invention can also use other methods to achieve rapid solvent volatilization, such as nitrogen purging and vacuum method, etc., to make the solvent volatilize quickly.

[0033] After the preparation of the perovskite thin film is completed, other functional layers of the battery can be prepared by methods such as scrape coating, coating, and vacuum method, etc., so as to complete the preparation of the battery.

[0034] Example 2

[0035] This embodiment is directed to a flexible substrate 7, and the substrate transmission mechanism in this embodiment is based on a roll-to-roll device. As Figure 3As shown in the figure, the substrate transfer mechanism in this embodiment includes a feeding reel 10, a turning roller 11, and a winding reel 12. Initially, the flexible substrate 7 is wound on the feeding reel 10, and the extending end of the flexible substrate 7 is wound on the winding reel 12 after passing around the turning roller 11. The turning roller 11 also functions as a tensioning reel, enabling the flexible substrate 7 between the feeding reel 10 and the turning roller 11 to have a certain tension to remain flat. The perovskite coating adjustment device and the anti-solvent coating adjustment device are placed above the flexible substrate 7 between the feeding reel 10 and the turning roller 11. The feeding reel 10 and the winding reel 12 are respectively driven to rotate by different motors. Additionally, a heating system is provided on the winding reel 12 to achieve rapid solvent volatilization. In this embodiment, the heating system includes a heating layer provided on the winding reel 12, and heating resistance wires are provided in the heating layer. After the heating resistance wires are powered on, heating is achieved. The heating system is equipped with a temperature sensor to maintain a constant heating temperature, and the heating system is a well-known technology in the art.

[0036] The specific preparation process of this embodiment is as follows:

[0037] First, the flexible substrate 7 is prepared. The flexible substrate 7 is first cleaned through a standard process and pre-deposited with each functional layer, and then the prepared flexible substrate 7 is wound on the feeding reel 10. Then, the feeding reel 10 and the winding reel 12 are started to achieve the transfer of the flexible substrate 7. The coating processes of the perovskite wet film 4 and the anti-solvent wet film 3 are the same as those in Embodiment 1. In this embodiment, it is also necessary to ensure that the anti-solvent wet film 3 is coated before the perovskite wet film 4 dries. The adjustment processes of the perovskite coating element 1 and the anti-solvent coating element 2 are the same as those in Embodiment 1. After the anti-solvent is scrape-coated, the perovskite film 4 needs to quickly remove the anti-solvent and the solvent to promote the crystallization and crystal growth of the perovskite thin film. In this embodiment, a heating system is provided on the winding roller 12 to achieve the purpose of rapid solvent volatilization.

Claims

1. A perovskite thin film preparation device, characterized in that: It includes a perovskite coating adjusting device, an anti-solvent coating adjusting device and a substrate transfer mechanism. The perovskite coating adjusting device and the anti-solvent coating adjusting device are both arranged above the substrate transfer mechanism. The perovskite coating adjusting device includes a first adjusting vehicle (101), a first flow control valve (105) and a perovskite coating element (1). The perovskite coating element (1) is arranged below the first adjusting vehicle (101) in a liftable manner and the flow rate is controlled by the first flow control valve (105). The anti-solvent coating adjusting device includes a second adjusting vehicle (201), a second flow control valve (205) and an anti-solvent coating element (2). The anti-solvent coating element (2) is arranged below the second adjusting vehicle (201) in a liftable manner and the flow rate is controlled by the second flow control valve (205). The first adjusting vehicle (101) and the second adjusting vehicle (201) both travel along the track (9); A first motor (102) is arranged inside the first adjusting vehicle (101), a second motor (202) is arranged inside the second adjusting vehicle (201). Gears are arranged on the output shafts of the first motor (102) and the second motor (202). A rack is arranged on the side wall of the track (9), and the gears are all meshed with the rack; A first lifting device (103) is arranged inside the first adjusting vehicle (101), and the perovskite coating element (1) is driven to lift by the first lifting device (103). A second lifting device (203) is arranged inside the second adjusting vehicle (201), and the anti-solvent coating element (2) is driven to lift by the second lifting device (203); The perovskite coating element (1) is connected to a perovskite liquid storage tank through a first pipeline (104), and the first flow control valve (105) is arranged on the first pipeline (104). The anti-solvent coating element (2) is connected to an anti-solvent storage tank through a second pipeline (204), and the second flow control valve (205) is arranged on the second pipeline (204). Both the first pipeline (104) and the second pipeline (204) are flexible hoses; The substrate first passes through the perovskite coating element to coat a layer of perovskite wet film, and then passes through the anti-solvent coating element when the perovskite wet film is not dry.

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