Suppression of vacancy aggregation by silicon-doping in low-temperature-grown Ga1−xCrxN

Abstract

Effect of Si doping on low-temperature grown GaCrN films has been investigated by positron annihilation spectroscopy. In undoped GaCrN films grown at 540 °C, vacancy clusters with sizes of V6–V12 were found to be responsible for positron trapping. Such vacancy clusters were considerably suppressed in Si-doped GaCrN films grown at 540 °C, although divacancies (VGaVN) still survived. The Si-doping may be one possible way to suppress vacancy aggregation during low temperature crystal growth, and the further methods to remove divacancies are required.