Papers by Author: S. Shevchenko

Abstract: We used the DLTS and photoluminescence (PL) techniques to study the deep states due to dislocations and deformation-induced point defects (PDs) in plastically deformed p-type germanium single crystals containing predominantly 60 dislocations with density ND, ranging from 105 to 106 cm-2. The narrow line near the temperature 140K dominates in the DLTS spectra. The ionization enthalpy and the capture cross section for holes traps indicate that the substitution copper atoms Cus are the main type of PDs. A decrease of the Cus atoms concentration and redistribution of the intensity in the PL spectra after the heat treatment of deformed samples at a temperature 500 °C are attributed to the diffusion of copper atoms to dislocations resulting in the appearance of “dirty” regular segments of 60 dislocations.

Abstract: Dislocation photoluminescence (DPL) is studied at 4.2K in plastically deformed germanium single crystals containing predominantly 60fl dislocations of “relaxed” morphology. The DPL spectra were deconvolved into Gaussian (Gm) lines of two groups over the range 0.5-0.6 eV. One of these lines corresponds to the radiation of 60fl dislocations with the equilibrium stacking fault width F0. To clarify the origin of the other Gm lines, the effect of both the dislocation density ND, ranging from106 to 109 cm-2, and the annealing at temperatures above 600flC on the intensity of Gm lines was investigated. The origin of different lines in the DPL spectra of germanium and silicon is discussed.