Li He, Wei Xianlong, Wu Gongtao, Gao Song, Chen Qing, Peng Lian-Mao
Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China.
Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China.
Ultramicroscopy. 2018 Oct;193:90-96. doi: 10.1016/j.ultramic.2018.06.015. Epub 2018 Jun 19.
Interlayer electrical transport between two-dimensional atomic crystals can be strongly modulated by the rotational misalignment between them. However, the experimental study on the interlayer electrical transport between rotated two-dimensional atomic crystals with variable rotation angles is challenging. Here, an in-situ scanning electron microscopy method is developed to study the interlayer electrical transport between rotated graphene layers. We employ nanoprobes installed in a scanning electron microscope to function as both "fingers" to induce interlayer rotation of a microfabricated metal-graphite-metal sandwiched island and also electrical probes to measure interlayer electrical resistivity of the rotated graphene layers. Interlayer electrical resistivity of the rotated graphene layers is found to increase monotonically by three orders of magnitude from ∼0.1 to ∼100 Ω cm when the rotational misalignment angle increases from 0° to 30°. This phenomenon can be well described by phonon-mediated electrical transport model. The large-magnitude tunability of interlayer electrical resistivity by mechanical rotation implies the potential applications of rotated graphene layers in nanoelectromechanical systems. Our results also provide a method for studying and tuning interlayer electrical transport between rotated two-dimensional atomic crystals.
二维原子晶体之间的层间电输运可通过它们之间的旋转失准得到强烈调制。然而，对具有可变旋转角度的旋转二维原子晶体之间的层间电输运进行实验研究具有挑战性。在此，我们开发了一种原位扫描电子显微镜方法来研究旋转石墨烯层之间的层间电输运。我们使用安装在扫描电子显微镜中的纳米探针，既作为 “手指” 来诱导微纳加工的金属-石墨-金属夹心岛的层间旋转，又作为电探针来测量旋转石墨烯层的层间电阻率。当旋转失准角从0°增加到30°时，发现旋转石墨烯层的层间电阻率从0.1到100 Ω·cm单调增加三个数量级。这种现象可以通过声子介导的电输运模型得到很好的描述。通过机械旋转实现的层间电阻率的大幅度可调性意味着旋转石墨烯层在纳米机电系统中的潜在应用。我们的结果还提供了一种研究和调节旋转二维原子晶体之间层间电输运的方法。
