Electrodeposition of SnO2 on FTO and its Application in Planar Heterojunction Perovskite Solar Cells as an Electron Transport Layer

We report the performance of perovskite solar cells (PSCs) with an electron transport layer (ETL) consisting of a SnO₂ thin film obtained by electrochemical deposition. The surface morphology and thickness of the electrodeposited SnO₂ films were closely related to electrochemical process conditions, i.e., the applied voltage, bath temperature, and deposition time. We investigated the performance of PSCs based on the SnO₂ films. Remarkably, the experimental factors that are closely associated with the photovoltaic performance were strongly affected by the SnO₂ ETLs. Finally, to enhance the photovoltaic performance, the surfaces of the SnO₂ films were modified slightly by TiCl₄ hydrolysis. This process improves charge extraction and suppresses charge recombination.