Trapping of Ce electrons in band gap and room temperature ferromagnetism of Ce4+ doped ZnO nanowires

Rare-earth (RE) metal doped ZnO nanowires have been fabricated through a simple, quick, and versatile low temperature soft chemical method. The average length and diameter of nanowires lie in range of 5 mu m and 60 nm, respectively. Raman and x-ray photoelectron spectroscopy studies demonstrate that Ce has 4+ oxidation state and successfully substitutes Zn up to 2.5% into ZnO single phase wurtzite structure. Doping of Ce shows a remarkably prominent large redshift of 22 nm in the UV region of the band gap, with an increase in the intensity of green emission band due to charge transfer of Ce4+ dopant. In addition, it has been interestingly found that RE (Ce) doped ZnO nanowires exhibit room temperature ferromagnetism, which makes them potential for spintronic devices with excellent optical characteristics. (C) 2009 American Institute of Physics. [doi:10.1063/1.3245325]