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 1×10¹⁶ cm^?2 Se ions at 100 keV. The total substitutional fraction of Se atoms in Si is 45% under the annealing at 800°C for 30 min and the peak concentration of substitutional Se atoms is exceeded 1×10²⁰ cm^?3. A temperature-independent carrier concentration of 3×10¹⁹ 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.