ZnTe nanowires overgrown by atomic layer deposited (Zn,Co) oxides: Raman scattering studies

Micro-Raman measurements were performed to study the vibrational properties of molecular beam epitaxy grown ZnTe nanowires (NWs) with atomic layer deposited (Zn,Co) oxides shell. A significant decrease of relative intensity of structures related to the ZnTe (NWs core) and Te (precipitates) phonons, resulting from the overgrowth of the NWs by the oxide shells is observed. The dependence of the Raman spectra on the laser power is shown and discussed. It is demonstrated that the crystallization of amorphous oxide shell and formation of Co3O4 crystals can be induced by increasing laser power during the measurements.