Luminescence from amorphous silicon nanostructures

We present a model of size-dependent luminescence from a-Si:H and show that a blueshift of the luminescence energy and a general increase in luminescence quantum efficiency are predicted as structure size decreases. In contrast to bulk a-Si:H structures, highly confined a-Si:H exhibits visible luminescence peak energies and high radiative quantum efficiency at room temperature, which is insensitive to changes in temperature or defect density. We also predict a decrease in mobility and radiative decay time as structure size shrinks. We compare our results with observations of visible light emission from porous silicon.