Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40254, Taiwan, Republic of China.
Nanotechnology. 2013 May 31;24(21):215603. doi: 10.1088/0957-4484/24/21/215603. Epub 2013 Apr 25.
The growth of Te nanotubes by the direct vapor phase process is dominated by the vapor-solid mechanism, where the intrinsic anisotropic crystal structure of tellurium and axial dislocations contained in the Te nanostructures should play crucial roles. During the growth process, Te nanoparticles will nucleate on the growth substrate in the initial stage, and then grow into nanoflakes and two-faced nanoscreens lying horizontally on the substrate until they fully cover the substrate. Some of the nanoscreens with certain horizontal angles with respect to the substrate surface will protrude out of the growth substrate and become preferential absorption sites for the incoming Te atoms. The two-faced nanoscreens then gradually develop into three-faced nanoscreens, four-faced nanogrooves, and finally perfect hexagonal nanotubes due to the lateral diffusion of Te atoms. Upon exposure to CO and NO₂ at room temperature, Te nanotube sensors showed the same direction of resistance change, adequate sensitivities, and fast response and recovery times, making them promising candidates for use in air-quality single sensors.
通过直接气相法生长的 Te 纳米管主要受气-固机制控制，其中碲的本征各向异性晶体结构和 Te 纳米结构中包含的轴向位错应该起着至关重要的作用。在生长过程中，Te 纳米颗粒将在初始阶段在生长衬底上成核，然后生长成纳米薄片和双面纳米筛，它们水平地躺在衬底上，直到完全覆盖衬底。一些相对于衬底表面具有一定水平角度的纳米筛会从生长衬底中突出出来，并成为进入的 Te 原子的优先吸收位点。然后，由于 Te 原子的横向扩散，双面纳米筛逐渐发展成三面纳米筛、四面纳米槽，最终形成完美的六方纳米管。在室温下暴露于 CO 和 NO₂时，Te 纳米管传感器表现出相同的电阻变化方向、足够的灵敏度以及快速的响应和恢复时间，这使得它们有望成为空气质量单传感器的候选材料。
