Stability of GaInP2 in H2SO4 Solution for Photoelectrochemical Water Splitting

Thin film of GaInP₂ has been investigated in 3 M H ₂SO₄ solution at different light intensities and at different polarization periods. Polarizations both under chopped light and at different light intensities reveal that the photocurrent is linear to the input light intensity, indicating that the material has an efficient charge transport process. At varied light intensities, photocurrent decays with time. XPS was used to study the depth profiles of fresh sample and the polarized ones. Photocurrent decay is then related to the surface In-rich and Ga- and P-deficient layer formation. This layer thickens with the polarization time, and it is due to the selective dissolution of Ga. For GaInP₂ film acting as a photoelectrode in photoelectrochemical water splitting, it will need protection to obtain a longer life time. copyright The Electrochemical Society.