• 文献标题:   Observation of Strain-Free Rolled-Up CVD Graphene Single Layers: Toward Unstrained Heterostructures
  • 文献类型:   Article
  • 作  者:   BARCELOS ID, MOURA LG, LACERDA RG, MALACHIAS A
  • 作者关键词:   graphene, rolledup tube, raman scattering, elasticity
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Univ Fed Minas Gerais
  • 被引频次:   16
  • DOI:   10.1021/nl5012068
  • 出版年:   2014

▎ 摘  要

Single layer graphene foils produced by chemical vapor deposition (CVD) are rolled with self-positioned layers of InGaAs/Cr forming compact multi-turn tubular structures that consist on successive graphene/metal/semiconductor heterojunctions on a radial superlattice. Using elasticity theory and Raman spectroscopy, we show that it is; possible to produce homogeneously curved graphene with a curvature radius on the 600-1200 nm range. Additionally, the study of tubular structures also allows the extraction of values for the elastic constants of graphene that are in excellent agreement with elastic constants found in the literature. However, our process has the advantage of leading to a well-defined and nonlocal curvature. Since our curvature radius lies in a range between the large radius studied using mechanical bending and the reduced radius induced by atomic force microscopy experiments, we can figure out whether bending effects can be a majoritary driving force for modifications in graphene electronic status. From the results described in this work, one can assume that curvature effects solely do not modify the Raman signature of graphene and that strain phenomena observed previously may be ascribed to possible stretching due to the formation of local atomic bonds. This implies that the interactions of graphene with additional materials on heterostructures must be investigated in detail prior to the development of applications and devices.