A Study on Improving the Properties of Wide Bandgap Perovskite Through Triple Halide Composition

The bandgap of halide perovskite materials can be easily adjusted through compositional variation. Perovskite solar cells (PSCs) have attracted attention as promising materials for tandem solar cells because of their tunable bandgaps. Nevertheless, the photoinduced halide segregation phenomenon, which is related to photostability and device performance, remains a problem. Herein, we confirmed that the perovskite composition was controlled by the triple halide composition through the addition of lead chloride (PbCl2). The triple halide composition not only controlled the perovskite bandgap but also suppressed the photoinduced halide segregation in the perovskite film. In addition, the device performance was improved by the enhanced crystallinity of the perovskite thin film with the triple halide composition.