Direct Observation of the Radial Breathing Mode in CdSe Nanorods

We experimentally confirm the existence of the radial breathing mode in CdSe nanorods by Raman spectroscopy, which was deduced from ab initio calculations of the vibrational properties of bare CdSe nanowires and CdSe/ZnS core-shell nanowires. We calculated the modes' frequency for various diameters and measured a set of bare CdSe nanorods and CdSe/ZnS core-shell nanorods to determine the diameter dependence of the modes' frequency. The frequency of this mode is strongly diameter dependent and it can be used to estimate the nanorod diameter from a Raman measurement alone.