Temperature-dependent Raman scattering studies in ZnSe nanoparticles

A study of the temperature-dependent Raman scattering of nanocrystalline ZnSe is presented and experimental results show weakly higher degree of anharmonicity in bulk compared to that in nanoparticles. Two different decay times tau(0) and tau(1) contributed to the phonon lifetime, temperature-independent tau(0) dominates for nanoparticles, while temperature-dependent tau(0) is important for bulk. Moreover, the asymmetry of the spectra is enhanced with the decreasing temperature, and surface phonon modes are considered as the main contribution to the asymmetry of the spectra. The frequency of the surface phonon mode softens and the ratio of the integrated intensities I-LO/I-SP increases with the increasing temperature. (c) 2005 Published by Elsevier B.V.Materials Science, MultidisciplinaryPhysics, AppliedSCI(E)EI0ARTICLE121484-14905