The effect of Si-nanocrystal size distribution on Raman spectrum

The effect of Si-nanocrystal (Si-nc) size distribution on Raman spectrum is studied in detail within the framework of a phonon confinement model. It is found that size distribution has little effect on Raman frequency shift, but greatly affects the width and shape of Raman spectrum. Si-nc Raman spectrum can be well explained by considering the size distribution. Furthermore, a set of simple relationships between Raman frequency shift/full width at half maximum (FWHM) and size distribution is set up based on the framework of a modified phonon confinement model, which can be applied to calculate Si-nc size distribution from the Raman spectrum. (C) 2011 American Institute of Physics. [doi:10.1063/1.3569888]