III-V nitride semiconductors for solar hydrogen production

Photoelectrochemical cells are devices that can convert solar radiation to hydrogen gas through a water decomposition process. In this process, energy is converted from incident photons to the bonds of the generated H-2 molecules. The solar radiation absorption, electron-hole pair splitting, and photoelectrolysis half reactions all occur in the vicinity of the electrode-electrolyte interface. As a result, engineering the electrode material and its interaction with the electrolyte is important in investigating and improving the energy conversion process in these devices. III-V nitride materials are promising candidates for photoelectrochemical energy applications. We demonstrate solar-to-hydrogen conversion in these cells using p-type GaN and n-type InGaN as a photocathode and photoanode material, respectively. Additionally, we demonstrate heteroepitaxial MOCVD growth of GaP on Si, enabling future work in developing GaPN as a photocathode material.