2, University of Nebraska, Lincoln, Lincoln, Nebraska, United States
Perovskite solar cells (PSCs) based on lead-containing hybrid organic-inorganic halide perovskites have demonstrated great promise as a new photovoltaic technology for the clean-energy future. However, the toxicity and the phase stability of these perovskites are of significant concern. In this context, we have theoretically predicted and experimentally validated a new group of all-inorganic halide perovskites based on the environmentally-friendly and earth-abundant element, titanium (Ti(IV)), which possess ideal optical bandgaps for solar cells. Further, we have developed low-temperature facile methods for fabricating high-quality Ti-based halide perovskite thin films. The physical properties of the as-prepared Ti-based halide perovskite thin films are measured, suggesting their superior potential in PSC applications. The formation mechanisms of these Ti-based halide perovskites and device physics of Ti-based PSCs are also studied extensively, the understanding from which provides guidance for further boosting the performance of Ti-halide-based PSCs.