State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, People's Republic of China.
Nanotechnology. 2011 Jul 1;22(26):265612. doi: 10.1088/0957-4484/22/26/265612. Epub 2011 May 17.
ZnO:Al thin films with Al incorporation of 0-20 at.% were deposited through the sol-gel technique. Such a film undergoes a significant microstructure development, from columnar to granular structures and then nanorod arrays with increasing Al content. The important role of Al incorporation level in the microstructure evolution was determined using scanning electron microscopy, x-ray photoelectron spectroscopy and transmission electron microscopy. At low Al level, the transition from columnar to granular grains can be attributed to the coarsening barrier resulting from the introduction of Al into the matrix. However, oriented structures of ZnO nanorod arrays are formed at a high Al level. TEM investigation reveals that a nanorod with smooth morphology at the top and rough morphology at the bottom has a single-crystalline wurtzite structure, which is the aggregation of nanoparticles of a few nanometers in size formed through the orientation attachment mechanism followed by epitaxial growth on the aggregated particles. Finally, the physical properties of the ZnO films with different degrees of Al concentration are discussed. Such detailed microstructure studies may aid the understanding of the doping effect process on the growth of a film, which is essential to altering its physical or chemical properties.
通过溶胶-凝胶技术沉积了 Al 掺杂浓度为 0-20 原子百分比的 ZnO:Al 薄膜。随着 Al 含量的增加，该薄膜经历了显著的微结构演变，从柱状结构到颗粒状结构，再到纳米棒阵列。使用扫描电子显微镜、X 射线光电子能谱和透射电子显微镜确定了 Al 掺杂水平对微结构演变的重要作用。在低 Al 水平下，柱状到颗粒状晶粒的转变可归因于 Al 引入基体引起的粗化障碍。然而，在高 Al 水平下形成了 ZnO 纳米棒阵列的取向结构。TEM 研究表明，具有顶部光滑形貌和底部粗糙形貌的纳米棒具有单晶纤锌矿结构，这是通过取向附生机制形成的粒径为数纳米的纳米颗粒的聚集，然后在聚集颗粒上进行外延生长。最后，讨论了具有不同 Al 浓度的 ZnO 薄膜的物理性质。这种详细的微观结构研究可能有助于理解掺杂对薄膜生长的影响过程，这对于改变其物理或化学性质至关重要。
