3 years ago

Spatially Resolved Modification of Graphene’s Band Structure by Surface Oxygen Atoms

Spatially Resolved Modification of Graphene’s Band Structure by Surface Oxygen Atoms
David Y. Lee, Colin Harthcock, Yi Zhang, Abdolreza Jahanbekam
We present the spatially resolved modification of the topography and electronic properties of monolayer graphene by a low dosage of atomic oxygen on the nanometer scale. Using the combination of an ultrahigh-vacuum scanning tunneling microscope and a gas beam of oxygen atoms, we show that the surface O-atoms, even at a low coverage of O/C = ∼1/150, serve as p-type dopants that leads to site-dependent partial and full graphene band modifications up to a gap of a few hundred millielectronvolts. The degree of modification and the number of O-atom-induced charge-holes per area are inversely proportional to the distance between the measuring position and the location of the nearest adsorbate. However, the number of holes contributed per oxygen atom is found to be a site-independent constant of 0.15 ± 0.05. For a small population of adsorbates taller than 4 Å, the graphene energy bands are no longer resolved; instead, our tunneling spectra show very spatially localized but highly dense states over a wide potential range, which indicates a sole tunneling contribution from the tall stacks of the electron-rich O-atoms and a complete decoupling from the graphene bands.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b05938

DOI: 10.1021/acs.jpcc.7b05938

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.