A Review on Stability Studies and Energy Recombination Losses in Different Electron Transport Layers for Solar Cells .

Electron Transport Layers (ETLs) play a crucial role in determining the efficiency and operational lifetime of solar cells. This review provides a comparative analysis of three major ETL materials: TiO, SnO, and ZnO, focusing on their stability studies and energy recombination loss analysis. While TiO remains a conventional benchmark, its photocatalytic degradation under UV light limits long-term success. ZnO offers high mobility but suffers from chemical instability at the perovskite interface. Our analysis highlights SnO as the most promising alternative due to its superior electron mobility, excellent energy level alignment, and lower recombination losses. This study underscores the importance of ETL selection for developing stable and high-performance solar devices.