Photoluminescence studies were carried out, at temperatures ranging from 5 to 296K, on I-doped epilayers which had been grown by molecular beam epitaxy. The samples exhibited excess electron concentrations which ranged from 8 x 1016 to 3 x 1018/cm3. Bright edge emission was observed at 296K. A deep-level band that was centered near to 1.45eV was observed at temperatures of up to 210K, and increased in intensity with doping level. The correlation of the growth parameters with photoluminescence data suggested that the deep-level band was associated mainly with donor-acceptor pair recombination that involved the shallow I donor, ITe, and the A-center acceptor complex, VCd-ITe. A zero-phonon emission that was related to this pair recombination occurred at 1.470eV at 5K. Thermal quenching of the integrated intensity of this donor-acceptor band was characterized by activation energies of 0.015 and 0.125eV; corresponding to the thermalization of electrons from shallow ITe donors to the conduction band and complete thermalization from the valence band to VCd-ITe centers, respectively.

J.Lee, N.C.Giles, D.Rajavel, C.J.Summers: Journal of Applied Physics, 1995, 78[9], 5669-74