%0 Journal Article %J Appl. Phys. Lett. %D 2014 %T Intermediate Band Conduction in Femtosecond-Laser Hyperdoped Silicon %A M. Sher %A Mazur, E. %X We use femtosecond-laser hyperdoping to introduce non-equilibrium concentrations of sulfur into silicon and study the nature of the resulting intermediate band. With increasing dopant concentration, the sub-bandgap absorption increases. To better understand the dopant energetics, we perform temperature-dependent Hall and resistivity measurements. We analyze the carrier concentration and the energetics of the intermediate band using a two- band model. The temperature-dependence of the carrier concentration and resistivity suggests that the dopant concentration is below the insulator-to-metal transition and that the samples have a localized intermediate band at 70 meV below the conduction band edge. %B Appl. Phys. Lett. %V 105 %P 032103-1–032103-5 %G eng %U /files/mazur/files/rep_709.pdf %R 10.1063/1.4890618