Stable response to visible light of InGaN photoelectrodes

The photoelectrochemical properties of InxGa1−xN∕GaN (0⩽x⩽0.20) epitaxial films on sapphire (0001) substrates have been investigated. The flatband potential of InxGa1−xN is shifted to more positive voltages with increasing indium incorporation. In aqueous HBr solution, the turnover number of the In0.20Ga0.80N electrode reaches 847 after 4000s illumination, which suggests that In0.20Ga0.80N has good photostability. Moreover, In0.20Ga0.80N shows highest visible-light response among InxGa1−xN (0⩽x⩽0.20) and the incident photon conversion efficiency is about 9% at 400–430nm in the HBr solution.