Ntwaeaborwa Odireleng Martin, Mofokeng Sefako J, Kumar Vinod, Kroon Robin E
School of Physics, University of the Witwatersrand, Private Bag 3, Johannesburg ZA2050, South Africa.
Department of Physics, CSET, University of South Africa, Johannesburg ZA1710, South Africa.
Spectrochim Acta A Mol Biomol Spectrosc. 2017 Jul 5;182:42-49. doi: 10.1016/j.saa.2017.03.067. Epub 2017 Apr 1.
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.
讨论了通过共沉淀法制备的铕（Eu）掺杂氧化锌纳米颗粒（NPs）的结构、颗粒形态和发光特性。当使用325nm的氦镉激光激发时，未掺杂的ZnO NPs微弱地表现出众所周知的紫外激子复合发射（在384nm处），并强烈地表现出与缺陷相关的宽带可见发射（在600nm处）。此外，当使用单色氙灯激发时，ZnO NPs在~600nm处表现出与缺陷相关的绿色发射。当使用单色氙灯激发材料时，观察到了归因于Eu离子D→F跃迁的线状发射。在本研究中，交换相互作用机制被确定为Eu掺杂ZnO NPs发光浓度猝灭的原因。
