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%).