Temperature-Dependent Raman Scattering of ZnSe Nanowires

Abstract

We present a Raman scattering study of ZnSe over a temperature range from 80 to 580 K. Both of TO and LO modes of ZnSe nanowires are observed a red-shift with elevating temperature, and its intrinsic broadening is larger than that of bulk counterpart. The opticalphonon lifetime of ZnSe nanowires are longer than that of nanoparticles but shorter than that of bulk, which can be attributed to the different surface to volume ratios. Some overtones and multi-phonon peaks are also observed at high temperature due to the larger wave vector q. The 2TA1(K) and multi-phonon peaks TA(X,K) + LA(X) appears at the temperature that is higher than room temperature. The intensity of overtones acoustics TA(L) elevates with increasing temperature while the surface mode disappears at temperature higher than 296 K. Detailed investigations on temperature-dependent phonon characteristics provide essential component for understanding confined phonons effects at small scale.