On the basis of magnetoluminescence spectroscopic data on a new iso-electronic defect complex in In-doped material, the local structure and the associated strain direction were identified. The strain-inducing complex had a tetrahedral structure which consisted of 2 substitutional In atoms, one Cd vacancy, and another Cd atom. Zeeman-effect data on the low-temperature photoluminescence were explained in terms of a modified effective Hamiltonian. It was shown that the symmetry of the exciton binding trap was less than trigonal. A bound exciton line at 1.58419eV (C-line) was found to be associated with this complex. It dominated the photoluminescence spectra in In-doped CdTe. Some 28 magnetic sub-components of the photoluminescence spectra of the C-line were resolved when the anisotropy of the Zeeman splitting was studied. A modified perturbation Hamiltonian furnished excellent agreement with the observed data. The C-line was attributed to a superposition of bound exciton recombinations from several inequivalent sets of tensile strained defects with an angle of inclination of 2 with respect to the trigonal [111] axis. The conduction-band g-factor (1.73), the valence-band parameters (K = 0.75, L = 0.0) and an additional strain constant ratio of -1.1, were suggested to be the first known values of this type for an iso-electronic trap of low symmetry. In a zero magnetic field, the bound exciton recombination from the inequivalent defects coincided, and resulted in a luminescence line with a half-width of only 0.00012eV. A temperature quenching of the total emission intensity was explained in terms of strains which were introduced by the defect complexes.

L.Worschech, W.Ossau, G.Landwehr: Physical Review B, 1995, 52[19], 13965-74