III-V Semiconductor Materials for Solar Hydrogen Production: Status and Prospects

Following recent developments in photoelectrochemical and photovoltaic-electrosynthetic systems, we present the benefits of III-V semiconductors for solar water splitting. In addition to their interesting light absorption and carrier transport properties, III-V alloys and multijunction structures enable the highest solar-to-hydrogen conversion efficiencies. However, many obstacles still stand in the way of practical realization of III-V solar water-splitting systems. Various surface protection strategies are being developed to address the instability of III-V semiconductors in an electrolyte. Meanwhile, multiple cost-reduction approaches are being implemented, including the use of solar concentration, epitaxial lift-off or spalling for substrate reuse, and monolithic or heterogeneous integration on silicon substrates. All these advances make III-V photoabsorbers a promising route toward decarbonated hydrogen production and pave the way to long-term deployment in real-world applications.