Improvement of photovoltaic performance of perovskite solar cells by interface modification with CaTiO3

Abstract The ETL/perovskite interface is crucial for the photovoltaic performance of perovskite solar cells (PSCs) because of its key role in electrons transport and charge recombination. Herein, an ultrathin CaTiO3 layer has facilely been fabricated and incorporated between the mp-TiO2 and perovskite layers. Due to the trap passivation effect and the optimized energy level alignment induced by modification, the electron transport is facilitated while the charge recombination is suppressed effectively. Therefore, the champion device gains a maximum PCE of 19.12% with the enhanced photovoltaic performance. In addition, the stability of PSCs has also been ameliorated by modification, and about 85% of the initial efficiency can be maintained even after exposure in ambient for 1000h.