On the origin of free carriers in high‐conducting n‐GaN

Abstract

Abstract Growth experiments with GaN in the system Ga/HCl/NH 3 /He at different growth temperatures show that the assumption of N‐vacancies to be responsible for the high n‐conductivity is questionable. The dependence of carrier concentration on growth temperature as well as the decrease in carrier concentration when additionally purified NH 3 is used indicate that donor impurities are incorporated. The most probable impurity is oxygen, substitutionally incorporated onto N‐sites. The observed growth rate dependence of carrier concentration can well be explained by a kinetically controlled incorporation process.