School of Advanced Materials Science and Engineering, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University (SKKU), Suwon 440-746, Republic of Korea.
Nat Commun. 2017 Jun 26;8:15891. doi: 10.1038/ncomms15891.
Gates can electrostatically control charges inside two-dimensional materials. However, integrating independent gates typically requires depositing and patterning suitable insulators and conductors. Moreover, after manufacturing, gates are unchangeable. Here we introduce tunnelling triboelectrification for localizing electric charges in very close proximity of two-dimensional materials. As representative materials, we use chemical vapour deposition graphene deposited on a SiO/Si substrate. The triboelectric charges, generated by friction with a Pt-coated atomic force microscope tip and injected through defects, are trapped at the air-SiO interface underneath graphene and act as ghost floating gates. Tunnelling triboelectrification uniquely permits to create, modify and destroy p and n regions at will with the spatial resolution of atomic force microscopes. As a proof of concept, we draw rewritable p/n and p/p junctions with resolutions as small as 200 nm. Our results open the way to time-variant two-dimensional electronics where conductors, p and n regions can be defined on demand.
盖茨可以静电控制二维材料内部的电荷。然而，集成独立的栅极通常需要沉积和图案化合适的绝缘体和导体。此外，制造后，栅极是不可改变的。在这里，我们引入隧道摩擦带电现象，以便在二维材料非常接近的地方定位电荷。作为代表性材料，我们使用化学气相沉积法在 SiO/Si 衬底上沉积的石墨烯。通过与涂有 Pt 的原子力显微镜尖端的摩擦产生的摩擦电荷，并通过缺陷注入，被捕获在石墨烯下方的空气-SiO 界面处，并充当幽灵浮栅。隧道摩擦带电现象独特地允许以原子力显微镜的空间分辨率随意创建、修改和破坏 p 和 n 区。作为概念验证，我们用分辨率低至 200nm 的重写 p/n 和 p/p 结。我们的结果为时变二维电子学开辟了道路，其中可以根据需要定义导体、p 和 n 区。
