• 文献标题:   Unexpected Hole Doping of Graphene by Osmium Adatoms
  • 文献类型:   Article
  • 作  者:   ELIAS JA, HENRIKSEN EA
  • 作者关键词:   electronic transport, hole doping, metal adatom, monolayer graphene device, osmium
  • 出版物名称:   ANNALEN DER PHYSIK
  • ISSN:   0003-3804 EI 1521-3889
  • 通讯作者地址:   Washington Univ
  • 被引频次:   2
  • DOI:   10.1002/andp.201900294 EA NOV 2019
  • 出版年:   2020

▎ 摘  要

The electronic transport of monolayer graphene devices is studied before and after in situ deposition of a sub-monolayer coating of osmium adatoms. Unexpectedly, and unlike all other metallic adatoms studied to date, osmium adatoms shift the charge neutrality point to more positive gate voltages. This indicates that osmium adatoms act as electron acceptors and thus leave the graphene hole-doped. Analysis of transport data suggest that Os adatoms behave as charged impurity scatterers, albeit with a surprisingly low charge-doping efficiency. The charge neutrality point of graphene is found to vary non-monotonically with gate voltage as the sample is warmed to room temperature, suggesting that osmium diffuses on the surface but is not completely removed.