Co-Electrodeposition of Sn-Doped TiO2 Electron-Transporting Layer for Perovskite Solar Cells

Sn-doped TiO2 films are successfully co-electrodeposited from a single bath containing TiCl3 and SnCl2, providing a new and facile method for the preparation of metal-doped TiO2 thin films. Through systematic examinations on the film morphologies, optical, and electronic properties of the electrodeposited TiO2 films with different Sn-doping amount, it is utilized as the electron-transporting layer (ETL) in a perovskite solar cell (PSC). The photovoltaic performance of PSCs equipped with electrodeposited Sn-doped TiO2 ETL is improved considerably, which is mainly attributed to the increased carrier concentration and improved electron extraction capability due to Sn-doping. Currently, power conversion efficiency of planar-type PSC using 5% (molar ratio) Sn-doped TiO2 ETL achieves 16.8%, corresponding to a 9.8% improvement when comparing with the sample using pure TiO2 (15.3%).