Thermal and Environmental Stability of Semi‐Transparent Perovskite Solar Cells for Tandems Enabled by a Solution‐Processed Nanoparticle Buffer Layer and Sputtered ITO Electrode

A sputtered oxide layer enabled by a solution-processed oxide nanoparticle buffer layer to protect underlying layers is used to make semi-transparent perovskite solar cells. Single-junction semi-transparent cells are 12.3% efficient, and mechanically stacked tandems on silicon solar cells are 18.0% efficient. The semi-transparent perovskite solar cell has a T 80 lifetime of 124 h when operated at the maximum power point at 100 °C without additional sealing in ambient atmosphere under visible illumination.