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采用球磨法制备了Zn1-xCoxO(x=0,0.004,0.008)纳米粉体,分别利用XRD,PL光谱和紫外-可见吸收光谱对样品进行了表征。XRD图谱显示样品呈六方纤锌矿结构,随着Co2+离子掺杂量的增加,晶格常数和平均晶粒尺寸略有减小。在PL光谱上观察到三个发光带:370nm处的本征发光峰、468nm附近的强蓝光发光峰,以及533nm附近的绿光发光峰。和球磨样品相比,1 200℃退火的样品的发光强度明显增强,这归因于退火使样品晶粒长大。在紫外-可见吸收谱上可以观察到两个吸收带:由ZnO的带隙吸收引起的360～388nm的强紫外吸收带和由Co2+离子的d-d跃迁引起的565nm附近的可见光吸收带。因此通过调节Co2+掺杂量和选择适当的退火温度可制备高质量的发光材料。
Zn1-xCoxO (x = 0,0.004,0.008) nanopowders were prepared by ball milling. The samples were characterized by XRD, PL and UV-Vis absorption spectra respectively. The XRD patterns show a hexagonal wurtzite structure. With the increase of Co2 + doping amount, the lattice constant and the average grain size decrease slightly. Three luminescence bands were observed on the PL spectrum: the intrinsic luminescence peak at 370 nm, the strong blue luminescence peak around 468 nm, and the green luminescence peak near 533 nm. The luminescence intensity of samples annealed at 1 200 ℃ is obviously enhanced compared with that of the ball-milled samples, which is attributed to the annealing of the sample grains. Two absorption bands are observed on the UV-visible absorption spectrum: a strong UV absorption band of 360 ~ 388nm caused by the band gap absorption of ZnO and a visible light absorption band of 565nm caused by the d-d transition of Co2 + ions. Therefore, by adjusting the amount of doped Co2 + and select the appropriate annealing temperature can be prepared high-quality light-emitting materials.