Dependence of the optoelectronic properties of selenium-hyperdoped silicon on the annealing temperature

Selenium-hyperdoped silicon was prepared by ion implantation at 100 eV to a dose of 6×1015 Se/cm2, followed by furnace annealing at 500–900 °C for 30 min. A phase transition from amorphous to crystalline was observed for the sample annealed at 600 °C. Carrier density in the Se doping layer gradually increases with the annealing temperature and a high carrier/donor ratio of 7.5% was obtained at 900 °C. The effects of annealing temperature on the rectifying behavior and external quantum efficiency of n+p junctions formed on Se-hyperdoped silicon were also investigated. We found that 700 °C was the optimal annealing temperature for improving the crystallinity, below-bandgap absorption, junction rectification and external quantum efficiency of Se-doped samples.