Air knife assisted crystallization perovskite solar cell and preparation method thereof

Abstract

The invention discloses an air knife assisted crystallization perovskite solar cell and a preparation method thereof, and belongs to the technical field of perovskite solar cells. The preparation method is characterized in that a hole transport layer is coated with a perovskite precursor solution to form a wet film, air flow with controllable temperature, flow, action time and angle is sprayed to the surface of the wet film through an air knife assisted crystallization technology, a solvent in the wet film is uniformly moved, and a perovskite light absorption layer is formed; and sequentially generating an electron transport layer and an electrode to obtain the perovskite solar cell. According to the invention, the air knife auxiliary crystallization technology is used for replacing traditional VCD, the problem of edge and center crystallization difference caused by vacuum degree propagation delay is overcome, high-quality and large-area uniform crystallization of the perovskite film is realized, and uniform coverage of the perovskite film is realized.

Description

TECHNICAL FIELD

[0001] The application relates to a perovskite solar cell with wind knife assisted crystallization and a preparation method thereof, and belongs to the technical field of perovskite solar cells. BACKGROUND

[0002] Perovskite solar cells have become a research hotspot due to their high photoelectric conversion efficiency and low cost. For the preparation of large-area components (area >= 50cm 2 The high quality and uniform crystallization of the perovskite light absorption layer is the key to improving the efficiency and stability of the components. At present, the vacuum assisted crystallization (VCD) method is commonly used in industrial production, that is, the solvent in the perovskite precursor wet film is quickly removed by a vacuum pump to induce rapid nucleation and growth of perovskite.

[0003] However, the VCD method has the following limitations: (1) it depends on large-scale vacuum equipment, and the initial investment and operation and maintenance cost are high; (2) it is difficult to ensure the instantaneous uniformity of the vacuum degree on a large-area substrate, which easily leads to uneven crystallization of the thin film, and defects such as pinholes or incomplete coverage; (3) the process is difficult to control, which is not conducive to continuous and high-speed production. SUMMARY

[0004] The purpose of the present application is to provide a perovskite solar cell with wind knife assisted crystallization and a preparation method thereof, which solves the problems of pinholes, incomplete coverage, dependence on large-scale vacuum equipment and high process controllability difficulty in the prior art when preparing perovskite solar cells.

[0005] To achieve the above purpose, the present application adopts the following technical solutions: In a first aspect, the present application provides a perovskite solar cell preparation method with wind knife assisted crystallization, comprising: preparing a hole transport layer on a transparent conductive substrate; coating a perovskite precursor solution on the hole transport layer to form a wet film, and spraying a gas flow with controllable temperature, flow rate, action time and angle on the surface of the wet film by a wind knife assisted crystallization technology to uniformly remove the solvent in the wet film, thereby forming a perovskite light absorption layer; preparing an electron transport layer on the perovskite light absorption layer; preparing an electrode on the electron transport layer to obtain a perovskite solar cell.

[0006] Further, the method of preparing a hole transport layer on a transparent conductive substrate comprises: depositing a layer of nickel oxide on the cleaned transparent conductive substrate by a magnetron sputtering method to form a nickel oxide layer, and modifying SAM molecules on the nickel oxide layer to form a hole transport layer.

[0007] Furthermore, the SAM molecule is MeO-2PACz.

[0008] Furthermore, the airflow velocity is 5~30 m / s, the airflow temperature is 20~60°C, and the airflow duration is 5~30 seconds.

[0009] Furthermore, the airflow is provided by a slit-type air knife device, wherein the length of the air knife outlet of the slit-type air knife device is not less than the width of the transparent conductive substrate.

[0010] Furthermore, after obtaining the perovskite light-absorbing layer, the method further includes: The perovskite light-absorbing layer is annealed to completely remove residual solvent.

[0011] Furthermore, the fabrication of an electron transport layer on the perovskite light-absorbing layer includes: A fullerene derivative layer and a polyethyleneimine layer are sequentially deposited on the perovskite light-absorbing layer to form an electron transport layer.

[0012] Furthermore, the fabrication of electrodes on the electron transport layer includes: Metal electrodes are deposited on the electron transport layer.

[0013] In a second aspect, the present invention provides a perovskite solar cell with air knife-assisted crystallization, which is prepared by the preparation method described in any one of the first aspects.

[0014] Furthermore, the effective area of ​​the perovskite solar cell is not less than 50 cm².

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention provides a perovskite solar cell with air knife-assisted crystallization and its preparation method. The air knife-assisted crystallization technology replaces the traditional VCD (vacuum-cooled disc) method. It rapidly removes the solvent through a controllable and uniform airflow. The airflow generated by the air knife-assisted crystallization technology has good uniformity across a wide area, and can act instantaneously and synchronously on the entire wet film surface. This overcomes the edge-to-center crystallization difference problem caused by vacuum propagation delay in VCD technology, thereby obtaining a highly uniform perovskite film on a large-area substrate. This achieves high-quality, large-area uniform crystallization of the perovskite film. By precisely adjusting the temperature, speed, angle, and action time of the airflow, the nucleation density and crystal growth kinetics of the perovskite can be finely controlled, thereby optimizing the film morphology and photoelectric performance. Furthermore, the process is controllable and has low difficulty.

[0016] The equipment structure is simplified, investment and operation and maintenance costs are significantly reduced, and it is easier to integrate into roll-to-roll (R2R) or sheet-to-sheet (Sheet-to-Sheet) continuous production lines to increase capacity.

[0017] The airflow is provided by a slit-type air knife device, and the length of the air knife outlet is not less than the width of the transparent conductive substrate to ensure the uniformity of airflow coverage. Attached Figure Description

[0018] Figure 1 This is a flowchart of a method for preparing perovskite solar cells using air knife-assisted crystallization, provided in an embodiment of the present invention. Figure 2 A schematic diagram illustrating the working principle of spraying airflow onto a wet film surface using air knife-assisted crystallization technology, provided in this embodiment of the invention; Figure 3 This is a schematic diagram of the structure of the perovskite solar cell provided in an embodiment of the present invention; Figure 4 The graphs show the current density-voltage characteristics of the perovskite solar cells prepared in Example 1 and Comparative Example 1. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0020] Example 1

[0021] according to Figure 1 The process shown in this embodiment demonstrates the fabrication of a perovskite solar cell with an effective area of ​​85mm × 85mm using the following method: Step 1: On the cleaned transparent conductive glass (specifically ITO in this embodiment), a layer of nickel oxide (NiO) is deposited using magnetron sputtering. x Then, SAM molecules (specifically MeO-2PACz in this embodiment) are modified on it by a scraping method to form a hole transport layer.

[0022] Indium oxycarbonate (ITO) is a functional material formed by coating a transparent conductive oxide film onto the surface of PET. It combines high light transmittance with electrical conductivity and is primarily used in perovskite photovoltaic cells, display devices, and building energy conservation. ITO specifically includes… Figure 3 The flexible conductive film and indium tin oxide shown are illustrated.

[0023] Step 2: Using a scraping method, a lead iodide formamidinium (FAPbI3)-based perovskite precursor solution is scraped onto the upper surface of the hole transport layer to form a wet film (composed of the perovskite precursor solution).

[0024] Step 3 (Key Step): As Figure 2As shown, after the coating is completed, the substrate is immediately horizontally conveyed to directly below the slit-type air knife device. The air knife outlet length is 140mm. The air knife is activated, spraying a uniform stream of dry air at a temperature of 50°C and a velocity of 20m / s onto the wet film surface for 10 seconds. The airflow rapidly carries away the solvent, inducing perovskite crystallization and forming a black, smooth, and uniform perovskite film (i.e., obtaining...). Figure 3 (The perovskite light-absorbing layer shown).

[0025] The perovskite film was annealed (100°C, 30 minutes) to completely remove residual solvent and optimize the crystal structure.

[0026] Step 4: Apply a PBCM (fullerene derivative) layer and a BCP (bath copper spirit) layer sequentially onto the perovskite light-absorbing layer using a blade coating method to form an electron transport layer.

[0027] Step 5: Prepare a metallic silver electrode by thermal evaporation to obtain a complete perovskite solar cell.

[0028] Comparative Example 1 The difference between this comparative example and Example 1 is as follows: Replace the air knife-assisted crystallization in step 3 with: rapidly transferring the substrate coated with the perovskite wet film into the vacuum chamber, starting the vacuum pump, reducing the chamber pressure to below 10 kPa within 5 seconds and maintaining it for 30 seconds to induce crystallization.

[0029] The performance of the perovskite solar cells prepared in Example 1 and Comparative Example 1 was tested, specifically by conducting standard sunlight (AM 1.5G, 100 mW / cm²). 2 Photoelectric performance testing under ( ).

[0030] according to Figure 4 The test results show that the perovskite solar cell prepared in Example 1 has a photoelectric conversion efficiency (PCE) of 20.1%, and its open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF) are all at high levels, verifying its advantages in large-area uniform film formation. Figure 4 The test results show that the photoelectric conversion efficiency (PCE) of the perovskite solar cell prepared in Comparative Example 1 is only 17.1%, and the open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF) are all lower than those of the perovskite solar cell prepared in Example 1.

[0031] Based on the above, the following conclusions can be drawn: The air-knife assisted crystallization method provided by this invention successfully replaces the traditional VCD technology for the fabrication of large-area perovskite solar cell modules. This method has significant advantages such as simple equipment, low cost, good film uniformity, wide process window, and ease of continuous production, and can be used for large-area (72.25 cm²) perovskite solar cell modules. 2 The components achieve a high efficiency of over 20%, demonstrating enormous potential for industrial application.

[0032] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing perovskite solar cells using air knife-assisted crystallization, characterized in that, include: Fabricating a hole transport layer on a transparent conductive substrate; A perovskite precursor solution is coated onto the hole transport layer to form a wet film. A controllable airflow with temperature, flow rate, action time, and angle is sprayed onto the surface of the wet film using air knife-assisted crystallization technology to uniformly remove the solvent in the wet film and form a perovskite light absorption layer. An electron transport layer is fabricated on the perovskite light-absorbing layer; Electrodes are fabricated on the electron transport layer to obtain a perovskite solar cell.

2. The method for preparing perovskite solar cells using air knife-assisted crystallization according to claim 1, characterized in that, The process of fabricating a hole transport layer on a transparent conductive substrate includes: depositing a nickel oxide layer on the cleaned transparent conductive substrate using magnetron sputtering to form a nickel oxide layer, and modifying the nickel oxide layer with SAM molecules to form a hole transport layer.

3. The method for preparing perovskite solar cells with air knife-assisted crystallization according to claim 2, characterized in that, The SAM molecule is MeO-2PACz.

4. The method for preparing perovskite solar cells using air knife-assisted crystallization according to claim 1, characterized in that, The airflow velocity is 5~30 m / s, the airflow temperature is 20~60°C, and the airflow duration is 5~30 seconds.

5. The method for preparing perovskite solar cells with air knife-assisted crystallization according to claim 1, characterized in that, The airflow is provided by a slit-type air knife device, wherein the length of the air knife outlet of the slit-type air knife device is not less than the width of the transparent conductive substrate.

6. The method for preparing perovskite solar cells with air knife-assisted crystallization according to claim 1, characterized in that, After obtaining the perovskite light-absorbing layer, the process further includes: The perovskite light-absorbing layer is annealed to completely remove residual solvent.

7. The method for preparing perovskite solar cells using air knife-assisted crystallization according to claim 1, characterized in that, The fabrication of an electron transport layer on the perovskite light-absorbing layer includes: A fullerene derivative layer and a polyethyleneimine layer are sequentially deposited on the perovskite light-absorbing layer to form an electron transport layer.

8. The method for preparing perovskite solar cells with air knife-assisted crystallization according to claim 1, characterized in that, The fabrication of electrodes on the electron transport layer includes: Metal electrodes are deposited on the electron transport layer.

9. A perovskite solar cell with air knife-assisted crystallization, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

10. The perovskite solar cell according to claim 9, characterized in that, The effective area of ​​the perovskite solar cell is not less than 50 cm². 2 .

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