• 文献标题:   Raman analysis of bilayer graphene film prepared on commercial Cu(0.5 at% Ni) foil
  • 文献类型:   Article
  • 作  者:   MADITO MJ, BELLO A, DANGBEGNON JK, OLIPHANT CJ, JORDAAN WA, MASIKHWA TM, MOMODU DY, MANYALA N
  • 作者关键词:   graphene raman, ni segregation, cu ni foil, apcvd graphene
  • 出版物名称:   JOURNAL OF RAMAN SPECTROSCOPY
  • ISSN:   0377-0486 EI 1097-4555
  • 通讯作者地址:   Univ Pretoria
  • 被引频次:   8
  • DOI:   10.1002/jrs.4848
  • 出版年:   2016

▎ 摘  要

This study reports the Raman analysis of bilayer graphene films prepared on commercial dilute Cu(0.5 at% Ni) foils using atmospheric pressure chemical vapor deposition. A bilayer graphene film obtained on Cu foil is known to have small areas of bilayer (islands) with a significant fraction of non-Bernal stacking, while that obtained on Cu/Ni is known to grow over a large area with Bernal stacking. In the Raman optical microscope images, a wafer-scale monolayer and large-area bilayer graphene films were distinguished and confirmed with Raman spectra intensities ratios of 2D to G peaks. The large-area part of bilayer graphene film obtained was assisted by Ni surface segregation because Ni has higher methane decomposition rate and carbon solubility compared with Cu. The Raman data suggest a Bernal stacking order in the prepared bilayer graphene film. A four-point probe sheet resistance of graphene films confirmed a bilayer graphene film sheet resistance distinguished from that of monolayer graphene. A relatively higher Ni surface concentration in Cu(0.5 at% Ni) foil was confirmed with time-of-flight secondary ion mass spectrometry. The inhomogeneous distribution of Ni in a foil and the diverse crystallographic surface of a foil (confirmed with proton-induced X-ray emission and electron backscatter diffraction, respectively) could be a reason for incomplete wafer-scale bilayer graphene film. The Ni surface segregation in dilute Cu(0.5 at% Ni) foil has a potential to impact on atmospheric pressure chemical vapor deposition growth of large-area bilayer graphene film. Copyright (C) 2015 John Wiley & Sons, Ltd.