ZnO nanostructures containing doped with different atom % of Nb are fabricated through ultrasound assisted hydrolysis in water. Effects of Nd incorporation on the structure, morphology, defect structure, optical, and magnetic behaviors of the nanostructures have been studied utilizing X-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy and magnetometry. We demonstrate that while Nb incorporation in ZnO nanostructures drastically modify their morphology and crystallinity, it does not affect the band gap energy of of ZnO significantly. While Nb incorporation in small concentration creates higher oxygen vacancy related defects in ZnO nanostructures, which are responsible for their visible emissions, incorporation of Nb in higher concentration reduces those defect structures from the band gap of the nanostructures. While oxygen vacancies have been frequently associated to the ferromagnetic behavior of ZnO nanostructures, our results indicate that a mere presence of oxygen vacancy in Nb-doped ZnO nanostructure does not guaranty their ferromagnetic behavior.
Band Gap Narrowing and Widening of ZnO Nanostructures and Doped Materials