Luminescence of black silicon

Room temperature visible and near-infrared photoluminescence from black silicon has been observed. The black silicon is manufactured by shining femtosecond laser pulses on silicon wafers in air, which were later annealed in vacuum. The photoluminescence is quenched above 120 K due to thermalization and competing nonradiative recombination of the carriers. The photoluminescence intensity at 10K depends sublinearly on the excitation laser intensity confirming band tail recombination at the defect sites.