Improved Stability of CsBi3I10 Based Pb-Free Perovskite Solar Cells

In the past few years, lead (Pb2+)-free perovskite or perovskite-like materials, in particular bismuth (Bi) based perovskite-like materials have attracted scientific community because of their excellent aerobic stability, and excellent optoelectronic characteristics. Cesium bismuth iodide (CsBi3I10) is all-inorganic perovskite-like material which has low band-gap (similar to 1.88 eV) and excellent aerobic stability. In present work, we demonstrated the fabrication of CsBi3I10 based Pb-free perovskite solar cells (LF-PSCs) with three different hole-transport materials (HTM). Spiro-OMeTAD was found to be more suitable HTM for the fabrication of LF-PSCs compared to the PTAA or P3HT HTM layers. Further, graphene oxide (GO) was incorporated with spiro-OMeTAD to enhance the long-term moisture-induced stability of the fabricated LF-PSCs. The best performing LF-PSCs device exhibited good efficiency of 1.09 % with excellent stability up to 1000 h.