Ramgir Niranjan S, Late Dattatray J, Bhise Ashok B, More Mahendra A, Mulla Imtiaz S, Joag Dilip S, Vijayamohanan K
Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008, India.
J Phys Chem B. 2006 Sep 21;110(37):18236-42. doi: 10.1021/jp0628131.
A simple method of vapor deposition for the shape selective synthesis of ZnO structures, namely, multipods, submicron wires, and spheres, has been successfully demonstrated. A plausible growth mechanism based on the studies of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) is proposed. Our studies suggest that the growth of a multipod structure is governed by the screw dislocation propagation while the vapor-liquid-solid (VLS) mechanism is responsible for the formation of submicron wires and spheres. Moreover, the flow rate of the carrier gas plays a crucial role in governing the morphology. Further, these structures exhibit an enhanced field emission behavior. The nonlinearity in the Fowler-Nordheim (F-N) plot, a characteristic feature of electron emission from semiconductors, is explained by considering the contributions from both the conduction and the valence bands of ZnO.
一种用于形状选择性合成氧化锌结构（即多脚结构、亚微米线和球体）的简单气相沉积方法已被成功证明。基于扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线衍射（XRD）和X射线光电子能谱（XPS）的研究，提出了一种合理的生长机制。我们的研究表明，多脚结构的生长受螺旋位错传播控制，而气液固（VLS）机制则负责亚微米线和球体的形成。此外，载气的流速在控制形态方面起着至关重要的作用。此外，这些结构表现出增强的场发射行为。通过考虑氧化锌导带和价带的贡献，解释了 Fowler-Nordheim（F-N）图中的非线性，这是半导体电子发射的一个特征。
