Optical and Electrical Properties of Single-Crystal Si Supersaturated with Se by Ion Implantation

Optical and electrical properties of single-crystal Si supersaturated with Se by ion implantation and followed by different thermal annealing conditions are reported.Si is implanted with 1×10^(16) cm^(-2) Se ions at 100 keV.The total substitutional fraction of Se atoms in Si is 45%under the annealing at 800℃ for 30 min and the peak concentration of substitutional Se atoms is exceeded 1×10^(20) cm^(-3).A temperature-independent carrier concentration of 3×10^(19) cm^(-3) is measured and the near-infrared absorption is closed to 30%.These results indicate the insulator-to-metal transition of the doped layer and the formation of impurity bands in the Si band gap.