All-Inorganic Perovskite Solar Cells: Modification Strategies and Challenges

Abstract

Cesium-based all-inorganic wide-bandgap perovskite solar cells (AIWPSCs) have been demonstrated with exceptional optoelectronic properties such as intrinsic optical wide-bandgap and high thermal stability, which make them suitable candidates for the front sub-cells of tandem solar cells (TSCs). Passivation of perovskite surface and interface is a matter of common interest in this community since all-inorganic perovskites always suffer from non-ideal crystallization such as phase impurity, high defect density, and non-uniform morphology. Despite these shortcomings, numerous efforts have been devoted in recent years to pursuing high-performance AIWPSCs, which exhibit an abruptly increased power conversion efficiency (PCE) from 2.9% to over 21.0%. In view of not having a thorough summary about the advancements on AIWPSCs, herein, a comprehensive review is given to highlight the recent device performance progress of AIWPSC, particularly focusing on the strategies to passivate the defects of all-inorganic perovskite, namely, additive engineering, solvent engineering, interface modification, and the exploration of new charge transport materials (CTMs) for improving the phase stability and PCE of AIWPSCs. Finally, a conclusive outlook on AIWPSCs will be given to provide our perspectives aiming to inspire the further development of AIWPSCs.