HI hydrolysis-derived intermediate as booster for CsPbI3 perovskite: from crystal structure, film fabrication to device performance

Abstract Nowadays, inorganic CsPbI 3 perovskite solar cells (PSCs) have become one of the most attractive research hotspots in photovoltaic field for its superior chemical stability and excellent photo-electronic properties. Since the first independent report in 2015, the power conversion efficiency (PCE) of CsPbI 3 based PSCs has sharply increased from 3.9% to 19.03%. Importantly, during the developing process of CsPbI 3 PSCs, HI hydrolysis-derived intermediate plays an important role: from stabilizing the crystal structure, optimizing the fabricated film to boosting the device performance. In this review, the different crystal and electronic structures of CsPbI 3 are introduced. We then trace the history and disputes of HI hydrolysis-derived intermediate to make this review more logical. Meanwhile, we highlight the functions of HI hydrolysis-derived intermediate, and systematically summarize the advanced works on CsPbI 3 PSCs. Finally, the bottlenecks and prospects are revealed to further increase the CsPbI 3 PSCs performance.