Preparation And Study Of Water Vapor Isolation Layer In Perovskite Solar Cells

In recent ten years,perovskite solar cells have been a hot research direction in the field of photovoltaic.Due to the excellent photoelectric properties of perovskite materials,the photoelectric properties of perovskite solar cell devices have improved rapidly in recent years.At the same time,its poor stability restricts the commercial development of perovskite solar cells.Under the influence of external water and oxygen environment,the internal functional layer of perovskite solar cells is easily degraded,which leads to the loss of device performance.To solve this problem,researchers have developed interface engineering,component engineering,additive engineering,encapsulation engineering and other technologies to enhance the humidity stability of devices.In this study,we combined interface engineering and encapsulation engineering techniques to prepare water vapor isolation layer inside perovskite devices and film encapsulation layer outside perovskite devices,using the synergistic effect to improve the long-term humidity stability of devices.Firstly,by utilizing the properties of precursor materials and the advantages of atomic layer deposition(ALD)technology,a dense and defect-free double-layer water vapor barrier consisting of SiAlxOy buffer layer and SiO2 water vapor isolation layer is prepared at a low temperature of 100℃.SiAlxOy buffer layer provides sufficient self-limiting reaction sites for SiO2 deposition,so that a more uniform and compact water vapor isolation layer is deposited at a lower temperature to better resist external water vapor.This double-layer water vapor barrier can effectively isolate external water vapor,prevent it from eroding the functional layer inside perovskite device,inhibit the migration of perovskite decomposition products and ions inside the device,and improve the humidity stability of the device.In addition,the SiAlxOy/SiO2 double-layer water vapor barrier can optimize the energy level arrangement of the device,which is conducive to the transfer of carriers between the interface,and further improve the photoelectric conversion efficiency of the device.On this basis,this study again uses ALD technology to SiO2 film as the device encapsulation layer,so that the performance of the device can be further optimized.Therefore,the photoelectric conversion efficiency of the device containing both double-layer water vapor barrier and film encapsulation layer is improved from 17.08%to 19.42%of the original device without any treatment.After aging for 3000 hours at 25 ℃ and 35±5%RH,the device still maintains more than 90%of the initial efficiency,showing excellent humidity stability.At the same time,SiAlxOy/SiO2 double-layer water vapor barrier and SiO2 film encapsulation layer still have excellent performance after application in 1 cm2 large area perovskite solar cell devices,showing their potential for large-scale industrial practical application,laying an important foundation for the commercial development of perovskite solar cells.