Perovskite solar cell based on air knife assistance and mixed solvent and preparation method and application thereof
By using mixed solvents and air knife-assisted technology in perovskite solar cells, the problems of uneven film formation and complex processes in PCBM coating solutions were solved, enabling efficient electron transport layer preparation, improving device performance and stability, and supporting large-area production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DAZHENG (JIANGSU) MICRO NANO TECH CO LTD
- Filing Date
- 2026-01-22
- Publication Date
- 2026-05-05
AI Technical Summary
In the prior art, the solution-prepared PCBM electron transport layer in perovskite solar cells has problems such as high solvent toxicity, poor wettability, uneven film formation and complex process, which limits the improvement of the performance of large-area modules.
By employing mixed solvents and air knife-assisted technology, the surface tension is reduced by adding alcohol co-solvents to the anisole solvent, and shear force and pressure are applied to the wet film using controlled airflow, thereby achieving uniform spreading and rapid drying of the PCBM coating liquid and forming a high-quality electron transport layer.
It significantly improves the uniformity of PCBM film formation on perovskite surfaces, enhances electron transport efficiency and device stability, and provides a feasible technical path for the large-scale production of perovskite solar cells.
Smart Images
Figure CN121985706A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a perovskite solar cell based on air knife assistance and mixed solvent, its preparation method and application, belonging to the field of perovskite solar cell technology. Background Technology
[0002] Perovskite solar cells have become strong contenders for next-generation photovoltaic technology due to their superior photoelectric conversion efficiency (PCE) and relatively low manufacturing cost. In perovskite solar cells with inverted planar heterojunction (pin) structures, fullerene derivatives, particularly methyl [6,6]-phenyl-C61-butyrate (PCBM), are widely used as electron transport layers (ETLs), which efficiently extract and transport electrons from the perovskite light-absorbing layer.
[0003] However, existing solution-based PCBM capping layers face several challenges: conventional solvents such as chlorobenzene are highly toxic and cannot be used for large-area production; pure anisole solvent is difficult to dry; and surface tension mismatch often results in the formation of uniform, dense films with good interfacial contact with the underlying perovskite. This leads to increased interfacial defects, intensified charge recombination, and severely hinders electron transport efficiency, ultimately limiting the improvement of large-area component performance.
[0004] To address the issues of anisole solvent interface and stability, numerous technological explorations have been undertaken. For example, some studies have combined metal-embedded fullerenes (such as Nd@C82) with polymers (such as PMMA) to form coupling interface layers, aiming to simultaneously improve electron extraction efficiency and device stability. Other technologies employ specific benzodithiophene compounds or cyano-containing alkoxysilane organic compounds as interface modification or passivation layers to improve perovskite crystal quality or passivate interface defects. While these methods are effective, they may involve complex material synthesis or multilayer structures, increasing process complexity. Summary of the Invention
[0005] The purpose of this invention is to provide a perovskite solar cell based on air knife assistance and mixed solvent, its preparation method and application, to solve the problems of high solvent toxicity and poor wettability of anisole on the perovskite surface, which makes it difficult to form a film, as well as the high process complexity caused by existing technologies in improving the electron transport layer.
[0006] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a method for fabricating a perovskite solar cell based on air knife assistance and a mixed solvent, comprising: A hole transport layer and a perovskite light absorption layer are sequentially fabricated on a transparent conductive substrate; A PCBM coating solution is obtained by dissolving PCBM in a mixed solvent of anisole and an alcohol-based co-solvent. The PCBM coating solution is loaded into a coating machine, and the coating machine and air knife system are started. Coating and air knife-assisted operations are performed simultaneously to form an electron transport layer. The coating operation involves applying the PCBM coating solution onto the perovskite light-absorbing layer through a slit coating head in the coating machine to form a PCBM wet film. The air knife-assisted operation involves spraying an airflow with controllable temperature, flow rate, pressure, action time, and angle onto the surface of the PCBM wet film through an air knife nozzle in the air knife system. A hole-blocking layer and electrodes are sequentially fabricated on the electron transport layer to obtain a perovskite solar cell.
[0007] Furthermore, the positions of the air knife nozzle and the slit coating head are relatively fixed.
[0008] Furthermore, the air knife nozzle is always positioned behind the slit coating head along a direction perpendicular to the substrate movement direction, and the distance between the air knife nozzle and the slit coating head is 3-6 cm, while the distance between the air knife nozzle and the perovskite light absorption layer is 3-5 cm.
[0009] Furthermore, the angle between the airflow ejected by the air knife nozzle and the perovskite light-absorbing layer is 40~60°.
[0010] Furthermore, the volume ratio of the anisole to the alcohol co-solvent is (3~5):1, and the alcohol co-solvent is one or more of isopropanol, ethanol and methanol.
[0011] Furthermore, the airflow is dried and filtered clean air or inert gas, the temperature of the airflow is 20~30℃, and the pressure of the airflow is 0.1~0.3 bar.
[0012] Furthermore, before loading the PCBM coating liquid into the coating machine, the process includes heating the PCBM coating liquid to 40~60°C.
[0013] Furthermore, the concentration of the PCBM coating solution is 10~20 mg / mL.
[0014] In a second aspect, the present invention provides a perovskite solar cell based on air knife assistance and mixed solvent, which is prepared by any of the preparation methods described in the first aspect.
[0015] Thirdly, the present invention provides an application of perovskite solar cells, using the perovskite solar cells described in the second aspect in the field of photovoltaic power generation.
[0016] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention provides a perovskite solar cell based on air knife assistance and a mixed solvent, along with its preparation method and applications. In preparing the PCBM coating solution, a mixed solvent is used. By adding a specific proportion of alcohol co-solvent to the anisole main solvent, the surface tension of the solution is significantly reduced, thereby achieving uniform wetting of the PCBM coating solution on the perovskite light-absorbing layer surface. The addition of an air knife assistance process, through controlled airflow, applies shear force and pressure to the wet film and accelerates local solvent evaporation, effectively suppressing the "coffee ring" effect and eliminating flow lines, forcing the solution to spread more uniformly. The air knife enables rapid and controllable drying of the PCBM wet film on the perovskite light-absorbing layer, forming a high-quality electron transport layer. The synergy of these two improvements fundamentally solves the problem of uniform PCBM film formation on large-area perovskite surfaces. This provides a practical and feasible core technology path for the large-scale, low-cost, continuous production of perovskite solar cells. Attached Figure Description
[0017] Figure 1 This is a flowchart of a method for fabricating a perovskite solar cell based on air knife assistance and mixed solvent, provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the perovskite solar cell provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a scenario where coating and air knife auxiliary operations are performed simultaneously, as provided in an embodiment of the present invention. Figure 4 The image shows the contact angle test results of different solvents on the perovskite light-absorbing layer provided in the embodiments of the present invention; the solvents corresponding to the three results from left to right are pure anisole, pure isopropanol, and a mixed solvent of anisole:isopropanol in a 5:1 (volume ratio); Figure 5 These are the current-voltage characteristic curves of the perovskite solar cells prepared in Example 1 and Comparative Example 1. Detailed Implementation
[0018] 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.
[0019] Example 1
[0020] according to Figure 1 The process shown in this embodiment involves fabricating perovskite solar cells using the following method: Step S1: The 220mm×220mm ITO film is scribed with P1, then washed with ethanol, washed with water, dried and plasma treated. Then, a 20 nm thick nickel oxide hole transport layer and a 470 nm perovskite light-absorbing layer are deposited sequentially on the ITO film to be used as substrates.
[0021] Step S2: Add 300 mg of PCBM powder to 15 ml of mixed solvent to obtain a PCBM coating solution with a concentration of 20 mg / ml. Stir for 5 h, sonicate for 15 min, and the resulting solution is named BJM-15. Then heat in a 40℃ water bath for 1 h.
[0022] In this embodiment, the mixed solvent is prepared by adding 5 ml of isopropanol to 25 ml of anisole and then sonicating for 15 min to obtain the mixed solvent.
[0023] Step S3: Perform preparatory work such as installing the blade head and leveling the coating machine. Connect the PCBM coating liquid obtained in step S2 to the slit coating blade head of the coating machine, and then simultaneously perform the coating operation and the air knife auxiliary operation (e.g., Figure 3 As shown, the coating operation involves applying PCBM coating liquid onto the perovskite light-absorbing layer through a slit coating head in a coating machine to form a PCBM wet film (each coating thickness is 2 micrometers, and a total of 2 coatings are applied, corresponding to 2 air knife assisted operations). The air knife assisted operation involves spraying a controllable airflow with adjustable temperature, flow rate, pressure, action time, and angle onto the surface of the PCBM wet film through an air knife nozzle in the air knife system. After the coating operation and the air knife assisted operation are completed, the electron transport layer can be obtained without annealing.
[0024] In this embodiment, the slit width of the air knife nozzle is 0.1 mm, and its length direction is parallel to the coating slit of the slit coating head. The slit width of the slit coating head is 0.05 mm, the gap value is 0.1 mm, and the moving speed of the slit coating head is set to 15 mm / s.
[0025] In this embodiment, the air knife nozzle is positioned 35 mm behind the coating slit head along a direction perpendicular to the substrate movement direction, at a height of 40 mm from the substrate, and the airflow pressure is 0.15 bar.
[0026] Step S4: Place the substrate into the vapor deposition chamber and deposit SnO2 using atomic layer deposition (ALD) to obtain a hole blocking layer, followed by P2 scribing.
[0027] Step S5: After scribing, ITO and Cu are deposited on the surface of the hole barrier layer using a vacuum evaporation process. Finally, P3 scribing is performed to obtain the desired result. Figure 2The perovskite solar cell with the structure shown.
[0028] Example 2
[0029] This embodiment uses the following method to prepare a perovskite solar cell: Step S1: The 220mm×220mm ITO film is scribed with P1, then washed with ethanol, washed with water, dried and plasma treated. Then, a 20 nm thick nickel oxide hole transport layer and a 470 nm perovskite light-absorbing layer are deposited sequentially on the ITO film to be used as substrates.
[0030] Step S2: Add 300 mg of PCBM powder to 15 ml of mixed solvent to obtain a PCBM coating solution with a concentration of 20 mg / ml. Stir for 5 h, sonicate for 15 min, and then heat in a 40 °C water bath for 1 h.
[0031] In this embodiment, the mixed solvent is prepared by adding 5 ml of isopropanol to 25 ml of anisole and then sonicating for 15 min to obtain the mixed solvent.
[0032] Step S3: Prepare the coating machine by installing and leveling the cutting head. Connect the PCBM coating liquid obtained in Step S2 to the slit coating head of the coating machine, and then perform the coating operation. The coating operation involves applying the PCBM coating liquid onto the perovskite light-absorbing layer through the slit coating head of the coating machine to form a PCBM wet film (each coating thickness is 2 micrometers, and a total of 2 coatings are applied, with each uniform film allowed to stand for 30 seconds to dry naturally after coating). After the coating operation is completed, anneal at 100°C for 12 minutes to obtain the electron transport layer.
[0033] In this embodiment, the slit width of the slit coating head is 0.05 mm, the gap value is 0.1 mm, and the moving speed of the slit coating head is set to 15 mm / s.
[0034] Step S4: Place the substrate into the vapor deposition chamber and deposit SnO2 using atomic layer deposition (ALD) to obtain a hole blocking layer, followed by P2 scribing.
[0035] Step S5: After scribing, ITO and Cu metals are deposited on the hole blocking layer surface using a vacuum evaporation process. Finally, P3 scribing is performed to obtain the perovskite solar cell.
[0036] Comparative Example 1 This comparative example fabricates perovskite solar cells using the following method: Step S1: The 220mm×220mm ITO film is scribed with P1, then washed with ethanol, washed with water, dried and plasma treated. Then, a 20 nm thick nickel oxide hole transport layer and a 470 nm perovskite light-absorbing layer are deposited sequentially on the ITO film to be used as substrates.
[0037] Step S2: Add 300 mg of PCBM powder to 15 ml of anisole to obtain a PCBM coating solution with a concentration of 20 mg / ml. Stir for 5 h, sonicate for 15 min, and the resulting solution is denoted as BJM. Then heat in a 40 °C water bath for 1 h.
[0038] Step S3: Prepare the coating machine by installing and leveling the cutting head. Connect the PCBM coating liquid obtained in Step S2 to the slit coating head of the coating machine, and then perform the coating operation. The coating operation involves applying the PCBM coating liquid onto the perovskite light-absorbing layer through the slit coating head of the coating machine to form a PCBM wet film (each coating thickness is 2 micrometers, and a total of 2 coatings are applied, with each uniform film allowed to stand for 30 seconds to dry naturally after coating). After the coating operation is completed, anneal at 100°C for 12 minutes to obtain the electron transport layer.
[0039] In this comparative example, the slit width of the slit coating head is 0.05 mm, the gap value is 0.1 mm, and the moving speed of the slit coating head is set to 15 mm / s.
[0040] Step S4: Place the substrate into the vapor deposition chamber and deposit SnO2 using atomic layer deposition (ALD) to obtain a hole blocking layer, followed by P2 scribing.
[0041] Step S5: After scribing, ITO and Cu metals are deposited on the hole blocking layer surface using a vacuum evaporation process. Finally, P3 scribing is performed to obtain the perovskite solar cell.
[0042] Comparative Example 2 This comparative example fabricates perovskite solar cells using the following method: Step S1: The 220mm×220mm ITO film is scribed with P1, then washed with ethanol, washed with water, dried and plasma treated. Then, a 20 nm thick nickel oxide hole transport layer and a 470 nm perovskite light-absorbing layer are deposited sequentially on the ITO film to be used as substrates.
[0043] Step S2: Add 300 mg of PCBM powder to 15 ml of anisole to obtain a PCBM coating solution with a concentration of 20 mg / ml. Stir for 5 h, sonicate for 15 min, and the resulting solution is denoted as BJM. Then heat in a 40 °C water bath for 1 h.
[0044] Step S3: Prepare the coating machine by installing and leveling the cutter head. Connect the PCBM coating liquid obtained in Step S2 to the slit coating cutter head of the coating machine, and then perform the coating operation. The coating operation involves applying the PCBM coating liquid onto the perovskite light-absorbing layer through the slit coating cutter head of the coating machine to form a PCBM wet film (each coating thickness is 2 micrometers, and a total of 2 coatings are applied). Correspondingly, the air knife assisted operation is also performed twice. The air knife assisted operation involves spraying a controllable airflow with adjustable temperature, flow rate, pressure, action time, and angle onto the surface of the PCBM wet film through the air knife nozzle in the air knife system. After the coating operation and the air knife assisted operation are completed, the electron transport layer can be obtained without annealing.
[0045] In this comparative example, the slit width of the air knife nozzle is 0.1 mm, and its length direction is parallel to the coating slit of the slit coating head. The slit width of the slit coating head is 0.05 mm, the gap value is 0.1 mm, and the moving speed of the slit coating head is set to 15 mm / s.
[0046] In this comparative example, the air knife nozzle is always positioned 35 mm behind the slot coating head, perpendicular to the direction of substrate movement, at a height of 40 mm from the substrate, and the airflow pressure is 0.15 bar.
[0047] Step S4: Place the substrate into the vapor deposition chamber and deposit SnO2 using atomic layer deposition (ALD) to obtain a hole blocking layer, followed by P2 scribing.
[0048] Step S5: After scribing, ITO and Cu metals are deposited on the hole blocking layer surface using a vacuum evaporation process. Finally, P3 scribing is performed to obtain the perovskite solar cell.
[0049] To verify the effectiveness of the present invention, the current-voltage characteristic curves of the perovskite solar cells prepared in Example 1 and Comparative Example 1 were tested, and the results are as follows: Figure 5 As shown. From Figure 5 The results show that this invention significantly improves the open-circuit voltage, short-circuit current density, fill factor, and photoelectric conversion efficiency of perovskite solar cells. In a 220mm × 220mm perovskite solar cell, the photoelectric conversion efficiency is improved by 22%.
[0050] To verify the effectiveness of the mixed solvent improvement proposed in this invention, the contact angles of different solvents on the perovskite light-absorbing layer were tested, and the test results are as follows: Figure 4 As shown, the results indicate that the mixed solvent of anisole and isopropanol in a 5:1 (volume ratio) exhibits the smallest contact angle on the perovskite light-absorbing layer, significantly reducing the surface tension of the solution.
[0051] To verify the effectiveness of the air knife-assisted operation improvement proposed in this invention, the influence of airflow angle was systematically studied.
[0052] When the angle between the airflow ejected from the air knife nozzle and the perovskite light absorption layer is 30°, the shear force of the airflow on the surface of the PCBM wet film is weak, which improves the leveling to some extent, but has limited effect on suppressing the coffee ring effect.
[0053] When the angle between the airflow ejected from the air knife nozzle and the perovskite light absorption layer is 45°, the balance between airflow shear and the vertical downward pressure component is better, which can effectively promote the lateral spread of the solution and stabilize the evaporation front, resulting in the best film quality.
[0054] When the angle between the airflow ejected by the air knife nozzle and the perovskite light absorption layer is 80°, the airflow impacts almost vertically. Although this can strongly suppress the thick edge, it may disturb the wet film surface, introduce new fluctuations, or even cause the substrate to become too cold and condense.
[0055] The angle between the airflow ejected by the air knife nozzle and the perovskite light absorption layer is within the range of 40~60°, which can achieve significantly better results than without air knife assistance.
[0056] 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 fabricating perovskite solar cells based on air knife assistance and mixed solvents, characterized in that, include: A hole transport layer and a perovskite light absorption layer are sequentially fabricated on a transparent conductive substrate; A PCBM coating solution is obtained by dissolving PCBM in a mixed solvent of anisole and an alcohol-based co-solvent. The PCBM coating solution is loaded into a coating machine, and the coating machine and air knife system are started. Coating and air knife-assisted operations are performed simultaneously to form an electron transport layer. The coating operation involves applying the PCBM coating solution onto the perovskite light-absorbing layer through a slit coating head in the coating machine to form a PCBM wet film. The air knife-assisted operation involves spraying an airflow with controllable temperature, flow rate, pressure, action time, and angle onto the surface of the PCBM wet film through an air knife nozzle in the air knife system. A hole-blocking layer and electrodes are sequentially fabricated on the electron transport layer to obtain a perovskite solar cell.
2. The method for fabricating perovskite solar cells based on air knife assistance and mixed solvent according to claim 1, characterized in that, The positions of the air knife nozzle and the slit coating head are relatively fixed.
3. The method for fabricating perovskite solar cells based on air knife assistance and mixed solvent according to claim 2, characterized in that, The air knife nozzle is always positioned behind the slit coating head along a direction perpendicular to the substrate movement direction, and the distance between the air knife nozzle and the slit coating head is 3-6 cm, while the distance between the air knife nozzle and the perovskite light absorption layer is 3-5 cm.
4. The method for fabricating perovskite solar cells based on air knife assistance and mixed solvent according to claim 1, characterized in that, The angle between the airflow ejected by the air knife nozzle and the perovskite light-absorbing layer is 40~60°.
5. The method for fabricating perovskite solar cells based on air knife assistance and mixed solvent according to claim 1, characterized in that, The volume ratio of the anisole to the alcohol co-solvent is (3~5):1, and the alcohol co-solvent is one or more of isopropanol, ethanol and methanol.
6. The method for fabricating perovskite solar cells based on air knife assistance and mixed solvent according to claim 1, characterized in that, The airflow is dried and filtered clean air or inert gas, the temperature of the airflow is 20~30℃, and the pressure of the airflow is 0.1~0.3 bar.
7. The method for fabricating perovskite solar cells based on air knife assistance and mixed solvent according to claim 1, characterized in that, Before loading the PCBM coating liquid into the coating machine, the process also includes a step of heating the PCBM coating liquid to 40~60°C.
8. The method for fabricating perovskite solar cells based on air knife assistance and mixed solvent according to claim 1, characterized in that, The concentration of the PCBM coating solution is 10~20 mg / mL.
9. A perovskite solar cell based on air knife assistance and mixed solvent, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 8.
10. An application of a perovskite solar cell, characterized in that, The perovskite solar cell described in claim 9 is used in the field of photovoltaic power generation.