Hot hole redistribution in impurity states of boron-doped silicon terahertz emitters

The relative intensities of emission peaks from boron-doped silicon terahertz sources have been measured under various pumping conditions. These data have been analyzed to determine the hole occupations in the excited states. As the pumping current increased, the hole concentrations increased approximately linearly. The hole population increased faster in the lower energy 1Γ8− state than in other excited states. At a fixed pumping current, the hole population decreased as temperature increased, but the decrease was slower for the 1Γ8− lower-energy state. These results suggest that to achieve terahertz emission at high temperatures it would be best to use dopants with transitions that have a strong oscillator strength from the lowest-energy excited state.