Confined optical phonon modes in polar tetrapod nanocrystals detected by   resonant inelastic light scattering
  We investigated CdTe nanocrystal tetrapods of different sizes by resonant inelastic light scattering at room temperature and under cryogenic conditions. We observe a strongly resonant behavior of the phonon scattering with the excitonic structure of the tetrapods. Under resonant conditions we detect a set of phonon modes that can be understood as confined longitudinal-optical phonons, surface-optical phonons, and transverse-optical phonons in a nanowire picture. 
R. Krahne, G. Chilla, C. Schueller, L. Carbone, S. Kudera, G.   Mannarini, L. Manna, D. Heitmannb, R. Cingolani