Surface optical phonon Raman scattering in Zn/ZnO core-shell structured nanoparticles

Surface optical (SO) phonon vibration mode predominant Raman scattering spectra were observed in the range of 545-565 cm(-1) in metal-semiconductor Zn/ZnO core-shell structured nanoparticles, prepared by laser ablation of a zinc target in a surfactant aqueous solution. The SO phonon mode exhibits significant size confinement effect. Such SO dominant Raman scattering is attributed to the existence of a large number of disorderly arranged areas among ultrafine ZnO grains formed under the extreme condition of laser ablation. This study demonstrates that the properties of surface phonons can availably reflect some important physical information. (c) 2006 American Institute of Physics.