Raman photoluminescence spectra of silicon nanowires synthesized by a vapor phase transport method

Silicon nanowires were successfully synthesized by a thermal evaporation method. We have observed a strong and broad emission band centered at 670 nm, which is attributed to the quantum confinement effect related to Si nanostructures embedded in the complex SiO x matrix. By fitting an experimental Raman spectrum, we confirm that the as-received wires possess crystalline silicon cores whose sizes were around 5 nm. Furthermore, the abnormal dependence of integral photoluminescence intensity on measured temperature was investigated.