Blue photoluminescence was successfully generated from zinc oxide by doping magnesium or cadmium. MgZnO and CdZnO films were deposited on glass substrates by a spin-on/pyrolysis with low heating temperatures (600-700°C) in H2 N2 and air, respectively. Structural analysis revealed that all the films were crystallized in the wurtzite-type structure. The c -axis length of ZnO was changed by the doping, indicating that Mg and Cd could be incorporated into the ZnO lattice through the present synthetic method. This incorporation was also supported by the occurrence of blue- and redshift of the optical bandgap by Mg and Cd doping, respectively. In case of MgZnO, the bandgap was increased up to 3.67 eV, resulting in a deep-level blue luminescence centered at 2.75 eV (corresponding to 451 nm) upon irradiation with UV light. This might be a color-tuning of the well-known green emissions from oxygen defect centers. In photoluminescence spectra of CdZnO, blue emission bands centered at 437 nm appeared by the Cd doping, possibly arising from the increased emissive defect centers related to interstitial zinc atoms. We could therefore produce two kinds of blue emissions of different origin from ZnO.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry