Electron hole drops in silicon with dislocations

Abstract

The processes of electron-hole drop (EHD) formation and migration in silicon crystal containing a significant number of dislocations can have different features as compared with those in dislocation-free crystal. The results of a low-temperature photoluminescence study of EHD in silicon with dislocations presented here show that dislocations in silicon are centres of EHD condensation. In addition to the line for dislocation-free silicon with a maximum at 1.082 eV, the radiative spectrum of EHD in silicon with dislocations contains an additional line with a maximum at 1.078 eV that is due to the appearance of unusual EHD extended or 'spread' along the dislocation axis. The existence of cylindrical EHD on dislocations is confirmed also by the different character of the dependence of the EHD recombination radiation intensity on the excitation intensity and is demonstrated by model calculations.