Preparation of flexible perovskite solar cells by a gas pump drying method on a plastic substrate

A uniform and full coverage perovskite film is of significant importance for flexible perovskite solar cells. In this study, highly efficient flexible perovskite solar cells were assembled using a flexible conductive plastic substrate by a one-step gas pump drying method to prepare high performance perovskite films under air conditions. The SEM results show that the perovskite film deposited on the flexible conductive plastic substrate was uniform, compact, and pinhole-free. The AFM results show that the film presented an extremely smooth surface morphology with a root mean square roughness of 15.8 nm in a large and representative scan area of 18 x 18 mu m(2). The flexible planar perovskite solar cell was fabricated, and all devices were prepared at 100 degrees C or below under air conditions. The highest efficiency on flexible substrates had reached 11.34% with an average efficiency of 8.93% for 14 solar cell devices.