Ultrathin amorphous zinc-tin-oxide buffer layer for enhancing heterojunction interface quality in metal-oxide solar cells

We demonstrate a tunable electron-blocking layer to enhance the performance of an Earth-abundant metal-oxide solar-cell material. A 5 nm thick amorphous ternary metal-oxide buffer layer reduces interface recombination, resulting in sizable open-circuit voltage and efficiency enhancements. This work emphasizes the importance of interface engineering in improving the performance of Earth-abundant solar cells.