Gallium phosphide (GaP) has a mid-sized optoelectronic bandgap well suited for solar-powered water electrolysis. One key deficiency of GaP and GaP-based alloys is their susceptibility to interfacial degradation/oxidation. High quality, protective native/thermal oxides are not tenable on Ga-based III-V semiconductors and presently there are few available chemical routes for protecting GaP surfaces. Passivation of GaP with thiols and sulfides are neither stable nor is their mode of attachment well understood, limiting their practical utility. Photochemical grafting of alkenes onto Ga-containing III-V semiconductors has been reported, but involves an initial pretreatment with inductively coupled hydrogen plasma.
Researchers at the University of Michigan have developed reactions between GaP(111) and Grignard reagents for introducing stable, protective alkyl surface groups that substantially inhibit surface oxidation and allow for modulation of the electrical properties of GaP contacts.
Applications and Advantages
- Functionalization of III-V semiconductor surfaces
- Control over the physicochemical and-nl-electrochemical properties of GaP-nl-interfaces that solve that the-nl-two distinct deficiencies that have-nl-historically limited the use of-nl-GaP in photoelectrochemical systems