Recent Advances of Device Components toward Efficient Flexible Perovskite Solar Cells

Flexible solar cells have launched potential applications in diverse areas, such as civil engineering, consumer electronics, electric automobile, and aerospace use. In recent years, perovskite solar cells (PSCs) have been successful with a rocketing power conversion efficiency (PCE) from 3.8% to 25.2% in the last decade. Due to its material flexibility, together with low-cost and facile fabrication processes, perovskites have certainly been considered as a promising candidate for the next generation of flexible solar cells. So far, the PCE of single-junction flexible perovskite solar cells (FPSCs) has reached 19.51%, which retains researchers' great enthusiasm for further development and applications of FPSCs. Herein, a brief review of the recent advances in the structural components of FPSCs is presented, including perovskite absorber layers, flexible substrates, transparent bottom electrodes, and charge carrier transport layers. In particular, the focus is on the development of low-temperature fabrication processes of the aforementioned compositional layer structures. Finally, noticeable achievements and annual milestones are discussed and summarized, and suggestions for further improvement of FPSCs and their ways toward commercialization are presented.