三维花状ZnO纳米材料的制备及发光性质

Synthesis and Photoluminescence Properties of 3-D Flower-like ZnO Nanomaterials

常压下用溶胶凝胶和化学溶液生长两步法在3种不同的衬底上制备出三维花状ZnO纳米材料。采用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、选区电子衍射(SAED)、紫外吸收(UV)光谱和光致发光光谱(PL)对样品进行分析,结果表明,花状ZnO的组成单元为沿c轴方向生长的ZnO纳米棒,直径约为100 nm,长度约为2μm;不同的衬底对花状ZnO形貌的影响不大,溶液的pH值对花状ZnO的形成有重要影响;紫外吸收谱在紫外区有强的宽带吸收,而室温下的光致发光谱则显示,421 nm(2.94 eV)处有较强的蓝光发射,520 nm(2.38 eV)和560 nm(2.21 eV)处有较弱的绿光发射,这使花状ZnO可能成为制作蓝光发光器件的材料。

Under ordinary pressure, 3-D flower-like ZnO nanomaterials were successfully synthesized by two steps of sol-gel and chemical solution growth methods with three different substrates. The samples were characterized by means of X-ray diffraction（XRD） , scanning electron microscopy（SEM） , transmission electron microscopy（TEM ）, selected-area electron diffraction （ SAED ）, ultraviolet absorption spectroscopy and photoluminescenee spectrum （PL）. The results indicated that the component units of flower-like ZnO were ZnO nanorods grown along the c-axis. The diameter and length of nanorods were approximately 100 nm and 2 μm, respectively. Different substrates had little effect on the morphology of flower-like ZnO and the solution pH value had great influence on the formation of flower-like ZnO. The ultraviolet absorption spectrum and photoluminescence spectrum of 3-D flowerlike ZnO nanomaterials indicated that the nanomaterials produced a strong broadband absorption in ultraviolet area, a strong blue emission at 421 nm and two weak green emissions at 520 nm and 560 nm. Therefore, this flower-like ZnO could be used to make the blue light emitting devices.