Zinc Selenide Nanoribbons and Nanowires

Zinc selenide nanoribbons and nanowires were obtained using laser ablation of ZnSe pressed powders. Their formation appeared to follow the vapor−solid and vapor−liquid−solid growth mechanisms, respectively. The product was characterized by means of scanning electron microscopy, transmission electron microscopy, micro-Raman scattering, and energy-dispersive X-ray spectroscopy. The ZnSe nanoribbons had a perfect wurtzite-2H single-crystal structure with a [120] growth direction and the {001} close-packed lattice planes of hexagonal ZnSe stacking along the nanoribbon width axis. The ZnSe nanowires grew with the {001} close-packed lattice planes of the wurtzite-2H structure stacking along the nanowire length axis. Both the longitudinal optic (LO) and transverse optic (TO) phonon peaks of the ZnSe nanowires and nanoribbons showed a clear shift toward low frequency relative to bulk values, probably because of small size and large surface effects. The ZnSe nanostructures exhibited strong self-activated luminescence centered at 596 nm.