Improved Stability of CsBi3I10 Based Pb‐Free Perovskite Solar Cells

Abstract

AbstractIn 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 (∼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.