SnO₂-Based Perovskite Solar Cells: Configuration Design and Performance Improvement

Organic-inorganic hybrid perovskite solar cells (PSCs) have developed rapidly in recent years owing to the low cost and high power conversion efficiency achieved. The excellent performance of PSCs is attributed to the superior electrical properties of each layer, including the electron transport layer (ETL), light-harvest layer, hole transport layer. As one of the most promising ETL materials for PSCs, SnO₂ shows excellent transmission, an appropriate energy band gap, a deep conduction band level, and high electron mobility, leading to efficient electron extraction and transport. Here, recent advancements in the PSCs with SnO₂ ETLs and endeavors aimed at improving the performance of this photovoltaic device are reviewed. Several typical configurations of SnO₂ based PSCs are discussed, including the planar structure, mesoporous structure, inverted structure and flexible PSCs. The efforts of modification and composite SnO₂ with other metal oxides are also assessed. Finally, an overview of the perspectives and challenges for the future of SnO2 based PSCs is provided.