Influence of hydrazinium iodide on the intrinsic photostability of MAPbI3 thin films and solar cells

In this study, an inorganic salt hydrazinium iodide (HAI) was introduced as an additive in the precursor solution to improve the intrinsic photostability of light absorber layer made of complex lead halide perovskite MAPbI3. Further, the effects of HAI addition on the photostability of MAPbI3 thin films, device performance and operational stability of solar cells were explored. Our findings show that the addition of HAI into MAPbI3 precursor increases the crystallinity of film, promotes the grain size with homogeneous film morphology and results in the intermediate formation. In turn, this improves the charge carrier recombination dynamics and quality of perovskite film, overall enhancing the photostability of the thin-film samples upon light exposure up to 1200 h. Furthermore, the addition of an optimal amount of HAI content shows improved power conversion efficiency of 17.03% and operational stability of ~80% (of the initial stage) after 4400 h of continuous illumination in an inert environment.