O2浓度对纳米氧化锌形貌、产量和发光性质的影响

目的研究不同O_2体积浓度下,双管管式炉内不同沉积位置处纳米ZnO形貌、产量和发光性质的变化规律。方法采用化学气相沉积法,在双管管式炉的三个不同沉积位置制备了具有不同形貌、产量和性质的纳米ZnO产物。采用扫描电子显微镜(SEM)、X-射线衍射仪(XRD)和荧光分光光度计(PL)等对产物的形貌、结构和光致发光性能进行表征和测试。结果 SEM表明O_2体积浓度较小时,有利于形成针状的多脚结构。O_2体积浓度较大时,有利于生成棒状的多脚状结构。通过对比沉积产物产量发现,当O_2体积浓度较低时,沉积反应主要发生在内管外。随着O_2体积浓度的增大,沉积产物逐渐向内管内部转移,内管口附近的沉积产物增多。XRD结果表明所有产物均为六方纤锌矿结构,当O_2体积浓度为0.0625%时,产物沿c轴择优生长。随着O_2体积浓度的增加,无明显择优取向。PL结果表明,紫外发射峰与绿光发射峰强度的比值随着O_2体积浓度的增加而增大,说明绿光发射峰主要由氧空位引起,随着O_2体积浓度的增加,氧空位逐渐减少。结论通过调节O_2体积浓度可以制备出不同形貌和发光性质的纳米ZnO,从而应用于不同领域,并且在适当的沉积位置可以获得最大产量。

Effects of O2 Concentration on Morphology, Yield and Luminosity of ZnO Nanostructures

The work aims to study effects of O2 concentration on morphology, yield and luminosity of ZnO nanostructures in different deposition positions in double-tube tubular furnace. ZnO nano products with different morphology, yield and luminosity were prepared in three different deposition positions in the furnace by chemical vapor deposition (CVD). Morphology, structure and photoluminescence performance were characterized with scanning electron microscopy (SEM), X-ray diffractometer (XRD) and fluorescence spectrophotometer (PL). Lower O2 concentration contributed to the growth of needle-like muti-legs structures, and higher O2 concentration contributed to rod-like muti-legs structures. The deposition reaction of ZnO mainly occurred outside the inner tube when the O2 volume concentration was lower. As O2 volume concentration increased, the deposition products moved toward interior of inner tube, and deposition products near inner pipe orifice increased. The XRD results showed that all the products were hexagonal wurtzite structure. The products preferentially grew along C axis when O2 volume concentration was 0.0625%, and no significant preferred orientation was detected as O2 volume concentration increased. PL results showed that green emission peak was mainly caused by oxygen vacancy as strength ratio of UV emission peak and green emission peak increased as O2 volume concentration increased. Oxygen vacancy decreased as O2 volume concentration increased. ZnO nanostructures with different morphology and luminosity can be prepared by adjusting O2 volume concentration, which can be applied in different fields. In addition, the maximum yield can be obtained in proper deposition position.