Study On Vacuum Co-Evaporated Wide-Bandgap Perovskite Films And Indoor Photovoltaic Devices

The organic-inorganic hybrid perovskite material has excellent optoelectronic properties and has been used in photovoltaic devices since 2009.The power conversion efficiency（Power Conversion Efficiency,PCE）of the device has increased from 3.8%to 25.7%（AM1.5G illumination）,which is comparable to the current commercial crystalline silicon cells.In indoor low-light scenarios,perovskite photovoltaic devices also show excellent performance.Recently,the perovskite photovoltaic cell developed by Saule Technologies achieved 25.5%efficiency in low light,taking the lead in entering the photov oltaic market.In this research,wide-bandgap perovskite thin films prepared by vacuum co-evaporation method and their indoor photovoltaic devices were studied,the following work was carried out:（1）Using MABr and PbI₂ as evaporation sources,wide-bandgap perovskite thin films were prepared by co-evaporation.The hole transport layer was modified with Al₂O₃ to improve the adsorption of organic matter on the substrate,thereby regulating the stoichiometric ratio of the p erovskite film and improving the quality of the perovskite film s.The corresponding device achieved a PCE of 21.37%under1000 lux illumination of a 3000 K white LED.（2）Incorporating CsCl into the perovskite component in an evaporative manner can passivate film defects and improve film morphology.The optimized thin film was applied to a photovoltaic device,and the device achieved a PCE of30.25%and an Open-Circuit Voltage(V_OC)of 1.00 V under 1000 lux illumination of a 3000 K white LED.At the same time,the device achieved an efficiency of 13.8%under an AM1.5G illumination.Based on the optimized perovskite film,a large-area module with an aperture area of 67.08 cm² was fabricated,achieving a PCE of13.25%under 1000 lux illumination of a 3000 K white LED,and a PCE of 9.70%under AM1.5G illumination.（3）Surface post-treatment of the film further improves the quality of the co-evaporated perovskite film.By treating the evaporated p erovskite film with MAC1solution and MAC1+MABr mixed solution,the grain size can be further increased,the crystallinity of the film can be enhanced,and the defects on the surface of the film can be passivated.Using the optimized perovskite thin film t o fabricate the device,the PCE reached 33.87%under 1000 lux illumination of 3000 K white LED.