Suppression of Undesired Losses in Organometal Halide Perovskite‐Based Photoanodes for Efficient Photoelectrochemical Water Splitting

Abstract

Organometal halide perovskites (OHPs) have become potential candidates for high-efficiency photoelectrodes for use in photoelectrochemical (PEC) water splitting. However, undesired losses, such as the non-radiative recombination of photogenerated carriers and sluggish reaction kinetics of PEC water splitting, are the main limitations to achieving maximum efficiency for OHP-based photoelectrodes. Herein, high-efficiency OHP-based photoanodes with a rational design that suppresses the undesired losses is reported. As a rational design for OHP-based photoanodes, the defect-passivated electron transport layers effectively suppress the undesired recombination of photogenerated carriers from the OHP layers. In addition, Fe-doped Ni3S2 with a high catalytic activity promotes the reaction kinetics of PEC water oxidation, thereby suppressing the undesired losses at the interface between the OHP photoanodes and electrolytes. The fabricated Fe-doped Ni3S2/Ni foil/OHP photoanodes exhibit a remarkable applied bias photon-to-current efficiency of 12.79%, which is the highest of the previously reported OHP-based photoanodes by suppressing undesired losses. The strategies for achieving high-efficiency OHP-based photoanodes provide insights into the rational design of photoelectrodes based on OHPs.