LAUSR

Abstract Perovskite solar cells (PSCs) have achieved remarkable power conversion efficiencies (PCEs) owing to their extraordinary optoelectronic properties. Electron transporting layer (ETL) has been proved to have a significant influence on the photovoltaic performance and stability of cell devices. Herein, for the first time, we prepare a low-temperature processed compact In2O3 film derived from a highly stable modified indium precursor solution as a promising ETL for stable and efficient air-processed PSCs. The addition of acetylacetone as a chelation ligand in the solution effectively inhibits the hydrolysis reactions by chelating In3+, thus contributing to the formation of compact In2O3 film at a low temperature of 200 °C. Dense CH3NH3PbI3 perovskite films with many microns-scale grains are fabricated using a scalable doctor-blade method under a harsh ambient condition (relative humidity of 40–50%). Using the proposed compact In2O3 film as ETL, the electron extraction and charge transport at the ETL/perovskite interface are significantly improved. As a result, the air-processed PSC based on compact In2O3 film delivers a champion PCE of 13.97%, greatly outperforming the device with a pristine In2O3 film (9.81%). In addition to high efficiency, the PSC incorporating proposed compact In2O3 film exhibits an excellent long-term stability, maintaining 94% of its initial PCE after stored in air for 31 days. This study demonstrates the feasibility of fabricating stable and efficient air-processed PSCs using low-temperature processed In2O3 ETL, which is expected to have a positive impact in the manufacturing community of solution-processed In2O3 film as well as air-processed PSCs.