Cathodoluminescence characterization of ZnO : Te microstructures obtained with ZnTe and TeO_2 doping precursors

Abstract

ZnTe- and TeO_2-doped ZnO nanostructures and microstructures were obtained by a vapour-solid process by sintering compacted ZnO powder mixed with each precursor. Cathodoluminescence (CL) measurements show that if TeO_2 is used, then the defect band, due mainly to O vacancies (V-O), tends to reduce and even disapear, which indicates that Te reacts with ZnO and passivates the O vacancies better than if ZnTe is used as a precursor. With both precursors, a CL peak at about 3.08-3.17 eV, which overlaps with that of ZnO at about 3.26 eV, indicates that ZnTe_xO_(1-x) forms.