Hierarchical Sn and AgCl co-doped TiO₂ microspheres as electron transport layer for enhanced perovskite solar cell performance

Controlled silver chloride (0.01–0.50 mol%) and tin co-doped micro-spherical titania (AgCl@Sn-TiO₂) with enhanced visible range absorption is prepared through hydrothermal synthesis. Multi-element doped rutile TiO₂ nanocrystalline electron transporting layer (ETL) in perovskite solar cell (PSC) is reported for the first time, which uplifts the photovoltaic performance comparing with undoped TiO₂ electrodes. Theoretical DFT studies, investigating the change in electronic density of states with respect to the doping are performed. An optimum efficiency of 10.4% was achieved for 0.01% doped AgCl@Sn-TiO₂, which provided highest efficiency with higher stability over 650 h comparing to undoped TiO₂ (10.0%) ETL based PSC prepared under the same ambient conditions. This report proves that, the AgCl@Sn-TiO₂ is one of the efficient materials having good potential for application in photoenergy conversion devices and may provide new insight into the design of advanced perovskite solar cells with titania based electron transport materials.