In Situ Observation of Electrostatic and Thermal Manipulation of Suspended Graphene Membranes
In Situ Observation of Electrostatic and Thermal Manipulation of Suspended Graphene Membranes
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DOI：
10.1021/nl301836q
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发表时间：
2012-11-01
期刊：
影响因子：
10.8
通讯作者：
Lau, Chun Ning
中科院分区：
文献类型：
--
作者：
Bao, Wenzhong;Myhro, Kevin;Lau, Chun Ning
石墨烯是自然界最薄的弹性膜，其形态对其电学、力学和机电性能有重要影响。在这里，我们报告了通过静电和热对悬浮石墨烯形态的操纵。控制。通过测量作为外加栅极电压和层数的函数的面外偏转，我们发现石墨烯采用抛物线轮廓。在大栅极电压下，电荷密度和应变分布不均匀。未夹紧的石墨烯薄片在张力作用下滑入沟槽；对于双箝位器件，有效杨氏模量E = 1.1 TPa的膜挠度可以很好地解释结果。当冷却到100 K时，我们观察到石墨烯的中心部分有屈曲引起的波纹，自由边缘有很大的向上屈曲，这是由石墨烯的大负热膨胀系数引起的。
Graphene is nature's thinnest elastic membrane, and its morphology has important impacts on its electrical, mechanical, and electromechanical properties. Here we report manipulation of the morphology of suspended graphene via electrostatic and thermal. control. By measuring the out-of-plane deflection as a function of applied gate voltage and number of layers, we show that graphene adopts a parabolic profile. at large gate voltages with inhomogeneous distribution of charge density and strain. Unclamped graphene sheets slide into the trench under tension; for doubly clamped devices, the results are well-accounted for by membrane deflection with effective Young's modulus E = 1.1 TPa. Upon Cooling to 100 K, we observe buckling-induced ripples in the central Portion and large upward buckling of the free edges, which arises from graphene's large negative thermal expansion coefficient.