Cu掺杂量对ZnO∶Cu纳米粉体发光性能的影响

为了考察Cu掺杂量对产物发光性能的影响,本文在PVA溶液中制备出Cu掺杂ZnO纳米粉体的前驱体,经500℃煅烧3h获得ZnO∶Cu纳米粉体.利用XRD、TEM分析了产物的结构和形貌,并采用FS分析了Cu掺杂量对产物发光性能的影响.研究结果表明所制备的产物具有六角纤锌矿结构,Cu的掺杂量不高于3∶100（摩尔比）时不影响产物的晶体结构;制得的粉体呈球形,大小均匀,分散性好,平均粒径为20~25nm.在以325nm波长激发的室温PL光谱中可以观察到Cu掺杂显著地抑制了本征态ZnO粉体的带边发射,随着Cu的掺杂量的增加,在400~428nm范围内出现较弱的蓝紫光发射,发射峰出现红移,且发射强度下降;在458nm和486nm处出现较强的蓝光发射,其中458nm的蓝光发射尤为显著,发射强度随着Cu的掺杂量的增加而下降;由于Cu的掺杂也导致520nm处的绿光发射减弱.

Effect of Cu Doping Dosage on the Photoluminescence Properties of ZnO Nano-powder

The precursors of ZnO · Cu nano powder were prepared in PVA aqueous solution. Then the products were obtained by calcining under 500 ℃ for 3h. The effect of doping dosage on the photoluminescence of the ZnO ： Cu nano powder was investigated. The products were characterized by XRD, TEM and Fluorescence spectrophotometer （FS）. The results of XRD indicated that all the products had a crystal structure of hexagonal wurtzite. Small quantity of Cu doping had no effect on the structure of the products. The TEM result showed that the nano-powder was spherical with the uniform size of 20-25 nm and had good dispersibility. It was found in the PL spectra excited with 325 nm light that the NBE of eigenstate ZnO was restrained observably by Cu doping. As the doping dosage increased, the violet-blue emission was observed at 400-428 nm weakly, the spectral had a red shift and the emission intensity decreased slightly. Two strong blue emission peaks were also observed at 458 nm and 486 nm, especially at the fomer. However the intensity of emission peak centered at 458 nm decreased slightly while the doping dosage increased. Furthermore, as a result of Cu doping, the green emission at 520 nm became weak obviously.