Imaging Electronic Structure of Carbon Nanotubes by Voltage-Contrast Scanning Electron Microscopy
Imaging Electronic Structure of Carbon Nanotubes by Voltage-Contrast Scanning Electron Microscopy
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DOI：
10.1007/s12274-008-8034-3
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发表时间：
2008-10-01
期刊：
影响因子：
9.9
通讯作者：
Krupke, Ralph
中科院分区：
文献类型：
--
作者：
Vijayaraghavan, Aravind;Blatt, Sabine;Krupke, Ralph
我们引入电压对比扫描电子显微镜（VC-SEM）的单壁碳纳米管的电子性质的视觉表征。VC-SEM涉及调整电子能带结构和成像的潜在分布沿着长度的纳米管。由此产生的二次电子对比度允许区分金属和半导体碳纳米管，并遵循半导体纳米管器件的开关，如原位电输运测量所证实的。我们证明，高密度阵列的单个纳米管器件可以快速，同时进行表征。结合有限元模拟的设备静电的漏电流模型，以解释所观察到的对比度演变的纳米管和表面电极。这项工作填补了分子器件结构电子表征的空白。
We introduce voltage-contrast scanning electron microscopy (VC-SEM) for visual characterization of the electronic properties of single-walled carbon nanotubes. VC-SEM involves tuning the electronic band structure and imaging the potential profile along the length of the nanotube. The resultant secondary electron contrast allows to distinguish between metallic and semiconducting carbon nanotubes and to follow the switching of semiconducting nanotube devices, as confirmed by in situ electrical transport measurements. We demonstrate that high-density arrays of individual nanotube devices can be rapidly and simultaneously characterized. A leakage current model in combination with finite element simulations of the device electrostatics is presented in order to explain the observed contrast evolution of the nanotube and surface electrodes. This work serves to fill a void in electronic characterization of molecular device architectures.