Najafi Mehrdad
Department of Physics, Shahrood University, University Boulevard, Shahrood, 3619995161, Iran.
J Fluoresc. 2016 May;26(3):775-80. doi: 10.1007/s10895-015-1756-1. Epub 2016 Jan 21.
Dysprosium (Dy) doped ZnO nanosheets and nanorods were synthesized by hydrothermal method. Effects of Cu doping, morphology and annealing in Oxygen ambient on structural and optical properties of ZnO nanostructures were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectra (DRS) and photoluminescence (PL) spectroscopy. This study recommends that both of intrinsic and extrinsic defects facilitate energy transfer (ET) from the ZnO host to Dy(3+) ions and consequently have an effective role on producing intense Dy emissions at indirect excitation. The results also revealed that annealing process improved the crystal structure of ZnO nanorods due to decrease of surface; however decreased ET and Dy emissions because of diminishing in oxygen vacancy. In addition, as a result of increasing of surface area in nanorods compared to nanosheets, the oxygen vacancies and ET were enhanced. Moreover the results exhibited that electrical and optical properties of ZnO:Dy can be tuned by various amount of Dy concentrations and also Cu doping.
采用水热法合成了镝(Dy)掺杂的ZnO纳米片和纳米棒。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、漫反射光谱(DRS)和光致发光(PL)光谱研究了Cu掺杂、形貌以及在氧气环境中退火对ZnO纳米结构的结构和光学性质的影响。本研究表明,本征缺陷和非本征缺陷均有助于能量从ZnO主体转移到Dy(3+)离子,因此在间接激发下对产生强烈的Dy发射具有有效作用。结果还表明,退火过程由于表面减少而改善了ZnO纳米棒的晶体结构;然而,由于氧空位减少,能量转移和Dy发射降低。此外,由于纳米棒的表面积比纳米片增加,氧空位和能量转移增强。而且结果表明,ZnO:Dy的电学和光学性质可以通过不同的Dy浓度以及Cu掺杂来调节。