Synthesis And Properties Of Cr-doped ZnO Nanowires By Electrispinning

In this thesis, we synthesized Cr-doped ZnO diluted magnetic semiconductor (DMS) nanowires by electrospinning method. Effects of post atmosphere (Air, H2 and O2) anneal processing on morphology and physical properties (photoluminescence and magnetic property) were investigated. The main results are as follows:X-ray photoelectron spectrum has been used to determinate the valence state of Cr ions in the samples. The Cr 2p 3/2 peak has been fitted at 576.6 eV, which can be deduced that Cr ions are substituted in 3+state. It indicates that chromium doping here is hole doping.A strong defect-related emission is observed in photoluminescence spectrum while the intensity of UV emission is relatively low. The suppression of Oxygen vacancies was found to favor the enhanced magnetic properties, which is supported by the Squid result in H2- annealed Cr-doped ZnO nanowires. Finally, the possible origin of magnetism in Cr-doped ZnO nanowires was discussed.