Structure, materials, and preparation of photoelectrodes

A main challenge on the way to viable photoelectrochemical (PEC) technologies is to develop inexpensive photoelectrodes that can deliver a stable performance with reasonable solar-to-fuel conversion efficiency on a timescale of years. Semiconductor photoelectrodes are at the core of PEC technologies, as they are responsible for harvesting light and for the generation of charge carriers that drive surface redox reactions. High-performance, durable photoelectrodes are typically composed not only of semiconductor light absorbers but also of additional materials that are necessary to provide complementary functionalities, e.g., conductive substrates (charge collectors), protection (or passivation) layers, cocatalysts, and photosensitizers, among others. In this chapter, we describe structure, materials, preparation and performance of photoelectrodes, focusing on metal oxide semiconductors.