Cost-effective solar water splitting with III-V/Si epitaxial photoelectrodes

In this contribution, we report on the recent achievement of epitaxial III-V/Si photoelectrodes for solar hydrogen production. After having recalled the motivation for producing hydrogen from renewable energies, [1-4] the basic concepts of electrochemistry will be first introduced, including overpotentials, catalysis and associated challenges. The physics of photoelectrochemical cells will then be explained, and the interest of using epitaxy for bandgap and band lineup engineering and doping control will be highlighted. [5-8] Finally, results obtained about the characterization of III-V/Si photoelectrodes using Pt, Ni or MoS2 catalysts, will be discussed in terms of stability, performance and cost. [9]