Electrical, optical and photocatalytic properties of doped ZnO nanoparticles

It is well known that the optical and electrical behaviours of semiconductor materials can easily be manipulated by incorporation of impurity atoms in their crystal structures. In this thesis project, modification of the structural, optical, electrical and photocatalytic properties of nitrogen doped or boron doped zinc oxide semiconductors was investigated. The undoped and different rates of B doped or N doped ZnO (1-5 wt%) powder samples were synthesized by mechanochemical technique. The produced metal oxides were then characterized using X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), Brunauer, Emmet and Teller (BET) method and dielectric spectroscopy (DS). The XRD patterns of samples were attributed to hexagonal wurtzite structure of ZnO. The Kubelka-Munk transformed DRS spectra of the samples indicated that the optical band gaps remained unchanged (3.38-3.48 eV). DS graphs of the samples suggested that the electrical parameters of the undoped ZnO were varied by N or B doping. The photocatalytic activities of the undoped, B doped and N doped ZnO samples were tested on the degradation of Rodamine B organic compound. The photodegredation efficiency calculations showed parallelism with spectroscopic measurements. N doping enhanced the photocatalytic activation of ZnO, whereas B doping worsened it. Keywords: Zinc Oxide, ZnO, semiconductor, photocatalyst, electrical and optical properties.