Department of Physics, Faculty of Science, UTM, Skudai, Johor 81310, Malaysia.
Ibnu Sina Institute, UTM, Skudai, Johor 81310, Malaysia.
Nanoscale Res Lett. 2014 May 23;9(1):256. doi: 10.1186/1556-276X-9-256. eCollection 2014.
The growth of Al:ZnO nanorods on a silicon substrate using a low-temperature thermal evaporation method is reported. The samples were fabricated within a horizontal quartz tube under controlled supply of O2 gas where Zn and Al powders were previously mixed and heated at 700°C. This allows the reactant vapors to deposit onto the substrate placed vertically above the source materials. Both the undoped and doped samples were characterized using scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) measurements. It was observed that randomly oriented nanowires were formed with varying nanostructures as the dopant concentrations were increased from 0.6 at.% to 11.3 at.% with the appearance of 'pencil-like' shape at 2.4 at.%, measuring between 260 to 350 nm and 720 nm in diameter and length, respectively. The HRTEM images revealed nanorods fringes of 0.46 nm wide, an equivalent to the lattice constant of ZnO and correspond to the (0001) fringes with regard to the growth direction. The as-prepared Al:ZnO samples exhibited a strong UV emission band located at approximately 389 nm (E g = 3.19 eV) with multiple other low intensity peaks appeared at wavelengths greater than 400 nm contributed by oxygen vacancies. The results showed the importance of Al doping that played an important role on the morphology and optical properties of ZnO nanostructures. This may led to potential nanodevices in sensor and biological applications.
采用低温热蒸发法在硅衬底上生长 Al:ZnO 纳米棒。在受控的 O2 气体供应下，在水平石英管内制备样品，其中 Zn 和 Al 粉末预先混合并在 700°C 下加热。这使得反应物蒸气沉积到垂直放置在源材料上方的衬底上。使用扫描电子显微镜 (SEM)、场发射扫描电子显微镜 (FESEM)、能谱 (EDX)、高分辨率透射电子显微镜 (HRTEM) 和光致发光 (PL) 测量对未掺杂和掺杂样品进行了表征。结果发现，随着掺杂浓度从 0.6 at.%增加到 11.3 at.%，形成了具有不同纳米结构的随机取向纳米线，在 2.4 at.%时出现了“铅笔状”形状，直径和长度分别为 260 到 350nm 和 720nm。HRTEM 图像显示纳米棒的条纹宽度为 0.46nm，相当于 ZnO 的晶格常数，并对应于生长方向的 (0001) 条纹。所制备的 Al:ZnO 样品表现出强烈的位于约 389nm 的紫外发射带（E g = 3.19eV），并且在大于 400nm 的波长处出现多个其他低强度峰，这是由氧空位贡献的。结果表明 Al 掺杂的重要性，它对 ZnO 纳米结构的形态和光学性质起着重要作用。这可能导致在传感器和生物应用中具有潜在应用的纳米器件。
