Designing a Transparent CdIn2S4/In2S3Bulk-Heterojunction Photoanode Integrated with a Perovskite Solar Cell for Unbiased Water Splitting

Linxing Meng, Min Wang, Haoxuan Sun, Wei Tian, Chenhong Xiao, Shaolong Wu,Fengren Cao, and Liang Li*

Adv. Mater.2020,32, 2002893

DOI: 10.1002/adma.202002893

The integration of photoelectrochemical photoanodes and solar cells to build an unbiased solar-to-hydrogen (STH) conversion system provides a promising way to solve the energy crisis. The key point is to develop highly transparent photoanodes, while its bulk separation efficiency (ηsep.) and surface injection efficiency are as high as possible. To resolve this contradiction, first a novel CdIn2S4/In2S3bulk heterojunctions in the interior of nanosheets is designed as a photoanode with high transparency and an ultrahighηsep.up to 90%. Furthermore, decorating the ultrathin amorphous SnO2layer by atomic layer deposition, the surface oxygen-evolution kinetics of the photoanode are increased significantly. As a result, the onset potential of the photoanode shifts negatively to 0.02 V vs RHE, and the photocurrent density boosts to 2.98 mA cm-2at 1.23 V vs RHE, which is ten times higher than that of pristine CdIn2S4. Such a high-performance photoanode enables the integrated metal sulfide photoanode–perovskite solar cell system to deliver a STH conversion efficiency of 3.3%.