• 文献标题:   Minimizing sputter-induced damage during deposition of WS2 onto graphene
  • 文献类型:   Article
  • 作  者:   JOHANSSON FOL, AHLBERG P, JANSSON U, ZHANG SL, LINDBLAD A, NYBERG T
  • 作者关键词:  
  • 出版物名称:   APPLIED PHYSICS LETTERS
  • ISSN:   0003-6951 EI 1077-3118
  • 通讯作者地址:   Uppsala Univ
  • 被引频次:   1
  • DOI:   10.1063/1.4977709
  • 出版年:   2017

▎ 摘  要

We demonstrate the sputter-deposition of WS2 onto a single-layer graphene film leaving the latter disorder-free. The sputtering process normally causes defects to the graphene lattice and adversely affects its properties. Sputtering of WS2 yields significant amounts of energetic particles, specifically negative S ions, and reflected neutral Ar, and it is therefore used as a model system in this work. The disorder-free sputtering is achieved by increasing the sputtering pressure of Ar thereby shifting the kinetic energy distribution towards lower energies for the impinging particle flux at the substrate. Raman spectroscopy is used to assess the amount of damage to the graphene film. Monte Carlo simulations of the sputtering process show that W is completely thermalized already at relatively low sputtering pressure, whereas Ar and S need a comparably higher pressure to thermalize so as to keep the graphene film intact. Apart from becoming completely amorphous at 2.3 mTorr, the graphene film remains essentially disorder-free when the pressure is increased to 60 mTorr. The approach used here is generally applicable and readily extendable to sputter-deposition of other material combinations onto sensitive substrates. Moreover, it can be used without changing the geometry of an existing sputtering setup. Published by AIP Publishing.