Photoelectrochemical water-splitting is a promising carbon-free fuel production method for producing H2 and O2 gas from liquid water. These cells are typically composed of at least one semiconductor photoelectrode which is prone to degradation and/or oxidation. Various surface modifications are known for stabilizing semiconductor photoelectrodes, yet stabilization techniques are often accompanied by a decrease in photoelectrode performance. However, the impact of surface modification on charge transport and its consequence on performance is still lacking, creating a roadblock for further improvements. In this review, we discuss how density functional theory and finite-element device simulations are reliable tools for providing insight into charge transport across modified photoelectrodes.
Keywords: 201 Electronics / Semiconductor / TCOs; 206 Energy conversion / transport / storage / recovery; 209 Solar cell / Photovoltaics; 212 Surface and interfaces; 401 1st principle calculations; 402 Multi-scale modeling; 50 Energy Materials; Density functional theory; charge transfer; device simulations; functionalized semiconductors; multiscale modeling; organic functionalization; passivation layers; photoelectrochemical water-splitting; photoelectrodes.