Role of shallow impurities and lattice defects in nucleation of electron-hole droplets in Si

Contribution of lattice defects and shallow impurities to electron-hole droplet (EHD) formation has been confirmed by the study on photoluminescence due to EHD's in various kinds of silicon crystals. Sample dependence of the EHD luminescence peak energy shift in the variation of the excitation intensity is explained in terms of the surface energy contribution to EHD binding energy and concentrations of EHD's and impurities.