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 4000 s 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 400-430 nm in the HBr solution. (C) 2008 American Institute of Physics.