Anharmonic phonon coupling in vapor-liquid-solid grown ZnO nanowires

We have determined quantitatively third-order anharmonic phonon Coupling matrix elements in vapor-liquid-solid (VLS) grown ZnO nanowires, via an analysis of the Raman line shape of the E-2(high) phonon mode. The results Suggest that the decay of the E-2(high) phonon into the sum of two acoustic phonons is suppressed in VLS-grown ZnO nanowires compared to bulk ZnO. While further studies are needed to elucidate the origin of this phenomenon. we suggest that isotope effects oil Zn vapor transport and diffusion through metal nanocatalysts, processes during the VLS growth. call be contributing mechanisms. (C) 2009 American Institute of Physics. [doi:10.1063/1.3263709]