ZnO nanostructures are extensively studied due to their attractive characteristics and behaviour with wide band gap (3.4 eV) and large exciton binding energy (60 meV) Recently, there have been a lot of interests in studying modified ZnO nanostructures. The prospect of magnetically controlled operation of semiconductor devices has provoked intensive research to develop transition metal doped wide-band-gap semiconductors,i.e. diluted magnetic semiconductors (DMS) with room temperature ferromagnetism. Among transition metals, Cu is an especially interesting dopant because that Cu-related compounds are not strongly ferromagnetic. Transition metal-doped ZnO offers the potential for realizing room temperature operation of active spintronic devices as well as rich and fascinating fundamental physics
