Chitin-integrated high-quality perovskite films for efficient solar cell fabrication in ambient conditions

Manufacturing halide perovskite films through methods like large-area coating in ambient air remains a challenge due to the sensitivity of perovskite compositions to humidity, which leads to the formation of pin-holes in the films. These pin-holes compromise both the performance and stability of perovskite solar cells. In this study, we effectively mitigated the formation of pin-holes in the perovskite films by incorporating chitin, a biomaterial, using a spin coating process under ambient conditions. Moreover, chitin passivates defects in the perovskite, such as dangling bonds at grain boundaries. As a result, chitin enhances both the stability and crystallinity of the films, facilitating the production of stable and efficient perovskite solar cells in an open-air environment.