Persistent photoconductivity and DLTS in indium-doped Cd0.9Mn0.1Te

The properties of an indium-related DX center were determined in indium-dop ed Cd-0.9 Mn0.1Te by deep-level transient spectroscopy (DLTS). These studie s, carried out within a 77-360K temperature range, revealed the presence of five electron traps. It was possible to determine the activation energy fo r four of them. Their values were equal to 0.22-0.30, 0.43, 0.51 and 0.63 e V, respectively. For the first energy level, the concentration of the assoc iated traps was higher than 10% of the concentration of the shallow levels and the capture cross section was thermally activated, with an energy barri er for capture equal to 0.1 eV. The concentration of the other three traps was lower than 10(14) cm(-3) Persistent photoconductivity was also observed at low temperatures. At 77 K, the photoconductivity continued for a very l ong time after the light was extinguished, and was present until the temper ature of the sample increased to 170 K. The very high concentration and the rmally activated capture cross section for the first trap suggest its DX ce nter nature. (C) 1999 Elsevier Science B.V. All rights reserved.