The effects of 2 intrinsic deep levels in semi-insulating crystals were reported. These levels were found in samples which were grown using conventional or high-pressure Bridgman techniques. The levels were observed, using thermoelectric effect spectroscopy, at distinct temperatures which corresponded to thermal ionization energies of Ev+0.735eV and Ev+0.743eV. The first level was associated with the doubly-ionized Cd vacancy acceptor, and the second level was tentatively identified as the Te antisite (TeCd); which was thought to be complexed with a vacancy. The second level was found to compensate the material electrically so as to produce high-resistivity crystals; provided that the Cd vacancy concentration was sufficiently reduced during growth or during post-growth thermal processing.

Electrical Compensation in CdTe and CdZnTe by Intrinsic Defects. N.Krsmanovic, K.G.Lynn, M.H.Weber, R.Tjossem, T.Gessmann, C.Szeles, E.E.Eissler, J.P.Flint, H.L.Glass: Physical Review B, 2000, 62[24], R16279-82