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 τ0 and τ1 contributed to the phonon lifetime, temperature-independent τ0 dominates for nanoparticles, while temperature-dependent τ0 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 ILO/ISP increases with the increasing temperature.