Ning Z Y, Fu M Q, Shi T W, Guo Y, Wei X L, Gao S, Chen Q
Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, People's Republic of China.
Nanotechnology. 2014 Jul 11;25(27):275703. doi: 10.1088/0957-4484/25/27/275703. Epub 2014 Jun 24.
The relationship between property and structure is one of the most important fundamental questions in the field of nanomaterials and nanodevices. Understanding the multiproperties of a given nano-object also aids in the development of novel nanomaterials and nanodevices. In this paper, we develop for the first time a comprehensive platform for in situ multiproperty measurements of individual nanomaterials using a scanning electron microscope (SEM). Mechanical, electrical, electromechanical, optical, and photoelectronic properties of individual nanomaterials, with lengths that range from less than 200 nm to 20 μm, can be measured in situ with an SEM on the platform under precisely controlled single-axial strain and environment. An individual single-walled carbon nanotube (SWCNT) was measured on the platform. Three-terminal electronic measurements in a field effect transistor structure showed that the SWCNT was semiconducting and agreed with the structure characterization by transmission electron microscopy after the in situ measurements. Importantly, we observed a bandgap increase of this SWCNT with increasing axial strain, and for the first time, the experimental results quantitatively agree with theoretical predictions calculated using the chirality of the SWCNT. The vibration performance of the SWCNT, a double-walled CNT, and a triple-walled CNT were also studied as a function of axial strain, and were proved to be in good agreement with classical beam theory, although the CNTs only have one, two, or three atomic layers, respectively. Our platform has wide applications in correlating multiproperties of the same individual nanostructures with their atomic structures.
性质与结构之间的关系是纳米材料和纳米器件领域中最重要的基本问题之一。了解给定纳米物体的多种性质也有助于新型纳米材料和纳米器件的开发。在本文中，我们首次开发了一个综合平台，用于使用扫描电子显微镜（SEM）对单个纳米材料进行原位多性质测量。长度范围从小于200纳米到20微米的单个纳米材料的机械、电学、机电、光学和光电子性质，可以在该平台上的SEM下，在精确控制的单轴应变和环境中原位测量。在该平台上对单个单壁碳纳米管（SWCNT）进行了测量。场效应晶体管结构中的三端电子测量表明，该SWCNT是半导体，并且与原位测量后的透射电子显微镜结构表征结果一致。重要的是，我们观察到该SWCNT的带隙随着轴向应变的增加而增大，并且首次实验结果与使用SWCNT的手性计算的理论预测定量一致。还研究了SWCNT、双壁碳纳米管和三壁碳纳米管的振动性能与轴向应变的关系，并且证明它们与经典梁理论非常吻合，尽管这些碳纳米管分别只有一、二或三个原子层。我们的平台在将同一单个纳米结构的多种性质与其原子结构相关联方面具有广泛的应用。
