Soft perovskites stabilized by robust heterojunctions

Rapid progress has recently been made in the development of perovskite solar cells (PSCs) with power conversion efficiencies (PCEs) that are now comparable with those of crystalline Si, the traditional and well-established solar cell technology. Recently in Science, Fang and co-workers reported a PSC in an inverted configuration with a high efficiency of >24% (23.5% certified) and remarkable operational stability. In this work, robust heterojunctions were constructed at the interface to suppress ion migration and favorably adjust the interfacial energy band alignment, addressing two major issues associated with the poor PCEs and stability of inverted PSCs.