Photoelectrochemical reaction and H2 generation at zero bias optimized by carrier concentration of n-type GaN

The authors studied the photoelectrochemical properties dependent on carrier concentration of n-type GaN. The photocurrent at zero bias became the maximum value at the carrier concentration of 1.7x10(17) cm(-3). Using the sample optimized carrier concentration, the authors achieved H-2 gas generation at a Pt counterelectrode without extra bias for the first time. The authors also discussed the mechanism of the dependence of photocurrent on the carrier concentration of GaN. (c) 2007 American Institute of Physics.