Light illumination of a gallium nitride photoelectrode creates separate electron-hole pairs that drive water oxidation and CO 2 reduction reactions. Here, we show enhanced photocurrent in an AlGaN/GaN device that consists of an unintentionally doped (uid-) AlGaN photoabsorption layer and an n + -GaN electrical-conduction layer. The production rate of formic acid by CO 2 conversion in the uid-AlGaN/n + -GaN photoelectrode is about double that in the uid-GaN/n + -GaN device. This improvement is most likely due to the effect of internal bias in the uid-AlGaN layer generated by the polarization effect, which improves electron-hole separation.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)