Shi Qiang, Wang Changzheng, Li Shuhong, Wang Qingru, Zhang Bingyuan, Wang Wenjun, Zhang Junying, Zhu Hailing
School of Physical Science and Information Engineering, Liaocheng University, Shandong 252059, People's Republic of China ; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, People's Republic of China.
Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, People's Republic of China ; School of Materials Science and Engineering, Liaocheng University, Shandong 252059, People's Republic of China.
Nanoscale Res Lett. 2014 Sep 10;9(1):480. doi: 10.1186/1556-276X-9-480. eCollection 2014.
Undoped ZnO, Ce-doped ZnO, and (Li, Ce)-codoped ZnO nanophosphors were prepared by a sol-gel process. The effects of the additional doping with Li ions on the crystal structure, particle morphology, and luminescence properties of Ce-doped ZnO were investigated by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy and photoluminescence spectroscopy. The results indicate that the obtained samples are single phase, and a nanorod shaped morphology is observed for (Li, Ce)-codoping. Under excitation with 325 nm light, Ce-doped ZnO phosphors show an ultraviolet emission, a green emission, and a blue emission caused by Zn interstitials. The spectrum of the sample codoped with a proper Li concentration features two additional emissions that can be attributed to the Ce(3+) ions. With the increase of the Li doping concentration, the Ce(3+) blue luminescence of (Li, Ce)-codoped ZnO is obviously enhanced, which results not only from the increase of the Ce(3+) ion concentration itself but also from the energy transfer from the ZnO host material to the Ce(3+) ions. This enhancement reaches a maximum at a Li content of 0.02, and then decreases sharply due to the concentration quench. These nanophosphors may promise for application to the visible-light-emitting devices.
78.55.Et; 81.07.Wx; 81.20.Fw.
采用溶胶-凝胶法制备了未掺杂的ZnO、Ce掺杂的ZnO和(Li, Ce)共掺杂的ZnO纳米磷光体。通过X射线衍射、扫描电子显微镜、X射线光电子能谱、电子顺磁共振光谱和光致发光光谱研究了Li离子的额外掺杂对Ce掺杂ZnO的晶体结构、颗粒形态和发光性能的影响。结果表明，所获得的样品为单相，(Li, Ce)共掺杂呈现纳米棒状形态。在325 nm光激发下，Ce掺杂的ZnO磷光体表现出紫外发射、绿色发射和由Zn间隙引起的蓝色发射。适当Li浓度共掺杂的样品光谱具有另外两种可归因于Ce(3+)离子的发射。随着Li掺杂浓度的增加，(Li, Ce)共掺杂的ZnO的Ce(3+)蓝色发光明显增强，这不仅源于Ce(3+)离子浓度本身的增加，还源于从ZnO主体材料到Ce(3+)离子的能量转移。这种增强在Li含量为0.02时达到最大值，然后由于浓度猝灭而急剧下降。这些纳米磷光体有望应用于可见光发射器件。
78.55.Et；81.07.Wx；81.20.Fw。
