Quantitative cathodoluminescence defect contrast studies were made of single grown-in and isolated glide dislocations in (111)CdTe samples at between 5 and 300K. Dark and bright cathodoluminescence defect contrasts which were observed in the low-temperature range exhibited thermally activated behavior or thermal quenching. An analysis of the contrast temperature dependence, which took account of temperature-dependent matrix parameters, permitted the demonstration of temperature-induced changes in the recombination activity of the dislocations. Bright cathodoluminescence contrast was correlated with the Te(g) line segments of glide dislocations in CdTe, and indicated a defect-bound radiative recombination. Its photon energy peak was at 1.48eV (5K), and the emission intensity was quenched above 120K. The operation of a defect-bound excitonic process was deduced from this. In spite of the different contrast behaviors, a qualitatively similar increase in the defect recombination strength with increasing temperature was deduced for the structurally different dislocations which were studied.

J.Schreiber, S.Hildebrandt, H.Uniewski, V.Bechstein: Materials Science and Engineering B, 1996, 42[1-3], 24-31