Study of deep acceptor states in undoped Semi-insulating GaAs with low carbon content by transient spectroscopy techniques

Abstract

Deep states in undoped semi-insulating GaAs with low carbon content were investigated by PICTS and Photo-DLTS. Hall and Photo-Hall measurements proved that peaks observed in Photo-DLTS spectra are due to the electron emission from deep donor states. Other peaks obtained in PICTS spectra were attributed to the hole emission from acceptor states with the apparent energy levels Epa= 0.18, 0.19, 0.21, 0.5 eV. A minimal value of their total concentration except of 0.5 eV level was estimated at about lx1015 ~m -~. The peak of 0.5 eV level with dominant amplitude in detected spectra correlates with the hole emission from EL2+/++ double donor state. The 0.19 and 0.21 levels are most probably related to the double acceptor GaAs antisite. defect.