Mute A, Peres M, Peiris T C, Lourenço A C, Jensen Lars R, Monteiro T
Departamento de Física and 13N, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
J Nanosci Nanotechnol. 2010 Apr;10(4):2669-73. doi: 10.1166/jnn.2010.1386.
Zinc oxide nanowires have been grown on alumina substrate by thermal evaporation of zinc nanopowder in the presence of oxygen flow. The growth was performed under ambient pressure and without the use of foreign catalyst. Scanning electron microscopy (SEM) observation showed that the as-grown sample consists of bulk ZnO crystal on the substrate surface with nanowires growing from this base. Growth mechanism of the observed morphology is suggested to be governed by the change of zinc vapour supersaturation during the growth process. X-ray diffraction (XRD) measurement was used to identify the crystalline phase of the nanowires. Optical properties of the nanowires were investigated using Raman scattering and photoluminescence (PL). The appearance of dominant, Raman active E2 (high) phonon mode in the Raman spectrum has confirmed the wurtzite hexagonal phase of the nanowires. With above bandgap excitation the low temperature PL recombination is dominated by donor bound exciton luminescence at -3.37 eV with a narrow full width at half maximum. Free exciton emission is also seen at low temperature and can be observed up to room temperature. The optical data indicates that the grown nanowires have high optical quality.
通过在氧气流存在的情况下热蒸发锌纳米粉，在氧化铝衬底上生长了氧化锌纳米线。该生长过程在常压下进行，且未使用外来催化剂。扫描电子显微镜（SEM）观察表明，生长后的样品由衬底表面的块状ZnO晶体组成，纳米线从该基底生长出来。观察到的形态的生长机制被认为受生长过程中锌蒸气过饱和度变化的支配。使用X射线衍射（XRD）测量来识别纳米线的晶相。使用拉曼散射和光致发光（PL）研究了纳米线的光学性质。拉曼光谱中占主导地位的拉曼活性E2（高）声子模式的出现证实了纳米线的纤锌矿六方相。在上述带隙激发下，低温PL复合主要由-3.37 eV处的施主束缚激子发光主导，半高宽较窄。在低温下也能看到自由激子发射，并且在室温下也能观察到。光学数据表明生长的纳米线具有高光学质量。
