Structural, optical and photoluminescence properties of Eu doped ZnO nanoparticles.
Odireleng Martin Ntwaeaborwa, Sefako J Mofokeng, Vinod Kumar, Robin E Kroon
Author Information
Odireleng Martin Ntwaeaborwa: School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg ZA2050, South Africa. Electronic address: ntwaeab@gmail.com.
Sefako J Mofokeng: Department of Physics, CSET, University of South Africa, Johannesburg ZA1710, South Africa.
Vinod Kumar: Photovoltaic Laboratory, Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016, India.
Robin E Kroon: Department of Physics, University of the Free State, Bloemfontein ZA9300, South Africa.
The structure, particle morphology and luminescent properties of europium (Eu) doped ZnO nanoparticles (NPs) prepared by co-precipitation method are discussed. When excited using a 325nm He-Cd laser, undoped ZnO NPs exhibited weakly the well-known ultraviolet excitonic recombination emission (at ~384nm) and strongly broad band visible emissions associated with defects (at ~600nm). In addition, the ZnO NPs exhibited green emission at ~600nm associated with defects when excited using a monochromatized xenon lamp. Upon Eu doping line emissions attributed to D→F transitions of Eu ions were observed when the materials were excited using a monochromatized xenon lamp. The exchange interaction mechanism is identified as the cause for concentration quenching of the luminescence of Eu doped ZnO NPs in this study.
