Bifunctional Hydroxylamine Hydrochloride Incorporated Perovskite Films for Efficient and Stable Planar Perovskite Solar Cells

Research on the addition of suitable materials into perovskite film for improved quality is important to fabricate efficient and stable perovskite solar cells. An attempt to enhance the quality of perovskite is performed by incorporation of a bifunctional hydroxylamine hydrochloride (HaHc) into pristine perovskite solution. On the one hand, the chloride ion in HaHc changes the crystallization kinetic and defect state of the perovskite film and a high-quality perovskite film with larger grain size and lower defect density is obtained. Perovskite solar cell (PSC) with HaHc additive exhibit a power conversion efficiency (PCE) of 18.69% with less hysteresis, which is obviously higher than that of pristine cells (16.85%). On the other hand, the hydroxyl group in HaHc can form a strong hydrogen bond with iodide ion in perovskite film to impede the decomposition of the film when under thermal annealing or storing in air. As a result, the PSCs with HaHc additive show superior thermal and air stability to the pristine devices. These results indicate that the addition of HaHc in perovskite film can greatly improve the performance of PSCs as well as their thermal and air stability.