Improved Stability of CsBi <sub>3</sub> I <sub>10</sub> Based Pb‐Free Perovskite Solar Cells
Khursheed Ahmad, Praveen Kumar, Mohammad Quasim Khan, Ali Alsulmi, Haekyoung Kim
Abstract
Abstract In the past few years, lead (Pb 2+ )‐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 (CsBi 3 I 10 ) 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 CsBi 3 I 10 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 P 3 HT 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.