INVESTIGATION OF THE LOW-TEMPERATURE CL CONTRASTS OF DISLOCATIONS IN COMPOUND SEMICONDUCTORS

Quantitative cathodoluminescence (CL) defect contrast studies were per formed at single grown-in and isolated glide dislocations in (001) GaP , (001) GaAs and (111) CdTe samples for temperatures T = 300-5 K. Bark and bright CL defect contrasts observed in the low temperature range exhibit thermally activated behavior or show thermal quenching, Analyz ing the contrast temperature dependence taking into account temperatur e-dependent matrix parameters allows to evidence temperature-induced c hanges of the recombination activity of the dislocations concerned. Th e results obtained for the misfit defects in GaP and As(g) dislocation s in GaAs proved in both cases non-radiative thermally activated defec t-bound recombination rates. The bright CL contrasts correlated with t he Te(g) line segments of glide dislocations in CdTe point out defect- bound radiative recombination. Its photon energy peak is at 1.48 eV (5 K), the emission intensity is quenched above T greater than or equal to 120 K, from what a defect-bound excitonic process might be conclude d. Despite the distinct contrast behaviors a qualitatively similar ris e of the defect recombination strength with increasing temperature is deduced for the structurally different dislocations studied.