Photoelectrodes with Enhanced Carrier Generation and Collection Through Optical Simulation and Materials Engineering

Abstract The efficiency of solar‐fuel conversion in photoelectrochemical (PEC) systems is hindered by significant losses of photons and photocarriers within the photoelectrodes. This study introduces an innovative ITO@In₂S₃ core‐shell nanowire structure designed to overcome these challenges through cutting‐edge materials engineering and sophisticated simulation techniques. Optical modeling and finite element simulations highlight the conflict between photocarrier generation and collection in planar In₂S₃ thin films and demonstrate how the core‐shell nanowire geometry can significantly enhance light absorption. The developed ITO@In₂S₃ nanowire photoanodes achieve a photocurrent of 11.3 mA cm⁻² at 1.23 V versus RHE, which is nearly five times greater than that of planar ITO/In₂S₃ thin films. Characterization techniques, including UV–vis absorption and charge separation efficiency measurements, confirm the enhanced light absorption and improved carrier collection facilitated by broadening the optical absorption range and reducing carrier transport distances. This research not only deepens the understanding of the dynamics within thin‐film photoelectrodes but also paves the way for the development of more efficient technologies for solar fuel conversion.