Optical properties of silicon nanowires from cathodoluminescence imaging and time-resolved photoluminescence spectroscopy

Time-resolved photoluminescence spectroscopy and cathodoluminescence spectroscopy and imaging have been used to investigate the optical properties of oxygen- and hydrogen-terminated silicon nanowires. We have found that the red- and the blue-emission bands from these nanowires are characterized by homogeneous broadening and are due to interface states in the silicon core and oxygen-based defects at the oxide cladding layer, respectively. Our results exclude the possibility that quantum confinement effects are responsible for these emission bands.