Abstract
In this work, Titanium-doped Zinc oxide (Ti-doped ZnO)nanostructures were synthesized by a two-step method and characterized. At first, the pure ZnO nanowires were synthesized by the thermal evaporation in a CVD process. Then the as-synthesized nanowires were doped with Titanium by the Metal vapor vacuum arc (MEVVA) system.From the FESEM and HRTEM observation, the morphology and the microstructure of the ZnO nanowires did not change after Ti doping. From the composition analysis of EDS and XPS, the Ti concentration increased from 0.33% to 2.36% with different dosages. The XRD and Raman spectrum showed no signal of titanium oxide, indicating that titanium existed in the ZnO structure in atomic state. We can find that the peak of UV emission shift to the higher energy region in the beginning and then to the lower energy region, indicating that the concentration of Ti might cause the optical band gap broadening or narrowing. In electrical measurement, the resistivity of a single ZnO nanowire decreases from 0.122Ωcm to 0.035Ωcm because of Ti doping and is 71.3% smaller than the resistivity of undoped ZnO nanowire. At the same time, the piezoelectric effect causes the resistivity of the ZnO nanowire increased when bending. Doping also improve the property of the field emission.