Influence of Mg Flux on the Photoelectrochemical Properties of p-Type GaN for Hydrogen Production

Abstract

This study investigates the effects of the doping flux of magnesium (Mg) on the photoelectrochemical (PEC) properties of p-type GaN. The Mg-doped GaN samples were deposited directly on c-plane Al2O3 substrates by metalorganic chemical vapor deposition (MOCVD). The Mg flux during growth was controlled by a mass flow controller at flows of 50, 100, 200, and 500 sccm. Optical property analysis revealed band-gaps for the films between 3.2 eV and 3.4 eV. The PEC properties of the films were examined by potentiostat with a three-electrode configuration. The photocurrent density of the 200 sccm sample was the highest, which would be attributed to vacancies or other intrinsic defects, such as interstitials and antisites, giving n-type conductivity.