The effects of growth temperature and Si doping upon the formation of vacancy defects in molecular beam epitaxy GaCrN films were studied using positron annihilation spectroscopy. No vacancy defects were detected in GaCrN films grown at 700C. In undoped GaCrN film grown at 540C, vacancy clusters with sizes of V8 to V12 were responsible for positron trapping. Vacancy clusters were much reduced by Si doping, but complexes related to nitrogen vacancies still survived.

Defect Structure of MBE-Grown GaCrN Diluted Magnetic Semiconductor Films. A.Yabuuchi, M.Maekawa, A.Kawasuso, S.Hasegawa, Y.K.Zhou, H.Asahi: Journal of Physics - Conference Series, 2011, 262[1], 012066