Mg doped SnO₂ electron transport layer enhances planar all inorganic perovskite solar cells efficiency

The electron transport layer (ETL) plays a crucial role in fabricating efficient and stable planar perovskite solar cells (PSCs). Among the various alternatives to TiO₂ for electron transport layers (ETLs), tin oxide (SnO₂) has emerged as a highly promising candidate due to its outstanding potential. However, improvements in SnO₂ materials remain necessary due to inherent limitations, such as low conductivity, high energy barrier, and interfacial defects. In this study, Mg²⁺ ions were introduced into SnO₂ to substitute Sn sites, leading to an increase in the open-circuit voltage (V_oc) of PSCs, and consequently enhancing overall device efficiency. With a Mg doping concentration of 3.0%, the V_oc and power conversion efficiency (PCE) of the solar cell reached 1.540 V and 7.17%, respectively. The incorporation of Mg²⁺ ions into SnO₂ presents an effective method to improve the performance of SnO₂ ETL in PSCs while utilizing more environmentally friendly solvents.