Morphological modification in CsBi3I10 perovskite thin films for solar cell devices

Perovskite materials have emerged as a key component in the evolution of lead-free perovskite solar cells (PSCs). This article explores morphological evolution in CBI perovskite thin films through compositional optimization and the fabrication of solar cell devices. The composition of CsBi 3 I 10 (CBI) is optimized by varying the CsI:BiI 3 ratio to 1.0:3, 1.2:3, 1.3:3, and 1.4:3. After a systematic investigation, the 1.3:3 ratio is found to be optimal. The physico-chemical analysis of the film has been performed. Morphological evolution, along with improved crystallinity, is observed. Furthermore, perovskite solar cell devices have been fabricated using CBI films of different compositions as photoactive materials. As a result of the compositional optimization, the CBI perovskite film prepared with a CsI:BiI 3 precursor ratio of 1.3:3 demonstrated the best photovoltaic performance, achieving a PCE of 3.1 ± 0.76 %.