Interfacial Band-Edge Energetic Control

Direct photoelectrochemical water splitting offers a sustainable way to produce carbon-neutral solar fuels in a potentially cost-efficient and scalable way. To date, many devices have been developed to achieve overall water splitting using only solar irradiation as the energy input. Most of these systems are made from semiconductor photoelectrodes, which are used to absorb light, separate photogenerated charge carriers, and perform catalysis. Significant overpotentials for catalysis are formed by the difference in the energy band levels of the semiconductors (and associated electrocatalysts) that determine the overall efficiency of these devices. Therefore it is critical to understand how these energetics of photoelectrodes interact with the electrolyte, and with each other in semiconductor/semiconductor, and semiconductor-metal junctions. This document aims to summarize the highest performing solar water splitting devices reported in literature, in the context of these interfaces energetic interfaces.