CuGaO 2 : A Promising Inorganic Hole‐Transporting Material for Highly Efficient and Stable Perovskite Solar Cells

The p-type inorganic semiconductor CuGaO2 as a hole-transporting layer (HTL) in perovskite solar cells (PSCs) provides higher carrier mobility, better-energy level matching, and superior stability, as well as low-temperature processing technique. Compared to organic HTL, a very competitive PCE of 18.51% with long-term stability is achieved. This indicates that CuGaO2 is a promising HTL for efficient and stable PSCs.