TiO2/SnOxCly double layer for highly efficient planar perovskite solar cells

Abstract Recently, perovskite solar cells have attracted tremendous research interest due to their amazing light to electric power conversion efficiency (PCE). However, most high performance devices usually use mesoporous TiO 2 as the electron transport layer (ETL), which increases cost for practical application. Here, TiO 2 /SnO x Cl y double layer was employed as the ETL for planar perovskite solar cells. Compared with bare TiO 2 , perovskite solar cell based on TiO 2 /SnO x Cl y shows drastically improved power conversion efficiency and reduced hysteresis. These improvements are attributed to TiO 2 /SnO x Cl y which could enhance electron extraction and reduce surface trap-state.