Observation of vacancies in Ga1-xMnxAs with positron annihilation spectroscopy

In English Positron annihilation spectroscopy can be used to determine the role of vacancy defects in semiconductors, by identification and quantification of the vacancies and their chemical surroundings. We have studied 0.5-0.8 mum thick low temperature MBE GaMnAs layers with Mn content 0.5-5% and different As-2 partial pressures at growth. The Doppler broadening results show that the Ga vacancy concentration in the layers decreases with increasing Mn content and decreasing As-2 partial pressure.