Measurements were made of the thermal recovery of the photo-current in semi-insulating material after photo-quenching of the EL2 defects at low temperatures. It was found that the determination of thermal regeneration rate parameters from measurements of photo-current recovery, by using a linear heating rate, required the consideration of the capture of electrons from regenerated EL2 centers by initially neutral residual acceptors. The rate parameters agreed with reported values that had been based upon infra-red absorption measurements. The residual acceptor density was estimated to be 2.3 x 1021/m3, while the EL2 density was 5.9 x 1021/m3.

I.K.Kristensen, S.Møller: Solid State Communications, 1996, 99[10], 751-4