Enhanced optoelectronic performance from the Ti-doped ZnO nanowires

Abstract

Ti-doped ZnO nanowires (NWs) were fabricated by thermal evaporation and metal vapor vacuum arc (MEVVA) ion implantation process. The effect of Ti doping on the structure, morphology, and electrical/optical properties of the as-grown NWs was investigated. The fraction of Ti doping was estimated to be 1 at. % to 2 at. % based on energy-dispersive x-ray spectroscopy (EDS). The x-ray diffraction analyses indicated that Ti-doped ZnO NWs are similar to ZnO NWs in crystal structure, which has been taken to indicate that no titanium oxide phase was produced. Cathodoluminescence (CL) spectra taken from the Ti-doped ZnO NWs at room temperature showed two distinct emission peaks, at 374 nm and at 752 nm. Electrical measurements showed that the resistivity of a single ZnO NW decreased from 1.22 × 10−1 Ω cm to 3.5 × 10−2 Ω cm with Ti doping. The semiconducting parameters of bent Ti-doped NWs squeezed between two approaching contacts inside the pole piece of the microscope were determined on the basis of experimentally recorded I–V curves. The approach suggests that one-dimensional nanostructures are suitable for application as optoelectronic devices.