Skip to main content
profile image
Selected Works of Santosh KC
Article
Air Stable p-Doping of WSe2 by Covalent Functionalization
ACS Nano (2014)
  • Peida Zhao, University of California, Berkeley
  • Daisuke Kiriya, University of California - Berkeley
  • Angelica Azcatl, University of Texas at Dallas
  • Chenxi Zhang, The University of Texas at Dallas
  • Mahmut Tosun, University of California - Berkeley
  • Yi-Sheng Liu, Lawrence Berkeley National Laboratory
  • Matt Hettick, University of California - Berkeley
  • Jeong Seuk Kang, University of California - Berkeley
  • Stephen McDonnell, University of Texas at Dallas
  • Santosh KC, The University of Texas at Dallas
  • Jinghua Guo, Lawrence Berkeley National Laboratory
  • Kyeongjae Cho, The University of Texas at Dallas
  • Robert M. Wallace, The University of Texas at Dallas
  • Ali Javey, University of California - Berkeley
Link Find in your library
Abstract
Covalent functionalization of transition metal dichalcogenides (TMDCs) is investigated for air-stable chemical doping. Specifically, p-doping of WSe2via NOx chemisorption at 150 °C is explored, with the hole concentration tuned by reaction time. Synchrotron based soft X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) depict the formation of various WSe2–x–yOxNy species both on the surface and interface between layers upon chemisorption reaction. Ab initio simulations corroborate our spectroscopy results in identifying the energetically favorable complexes, and predicting WSe2:NO at the Se vacancy sites as the predominant dopant species. A maximum hole concentration of ∼1019 cm–3 is obtained from XPS and electrical measurements, which is found to be independent of WSe2 thickness. This degenerate doping level facilitates 5 orders of magnitude reduction in contact resistance between Pd, a common p-type contact metal, and WSe2. More generally, the work presents a platform for manipulating the electrical properties and band structure of TMDCs using covalent functionalization.
Keywords
  • layered materials,
  • covalent binding,
  • NO2,
  • chemisorption,
  • doping
Disciplines
Publication Date
September 17, 2014
DOI
10.1021/nn5047844
Publisher Statement
SJSU users: Use the following link to login and access the article via SJSU databases.
Citation Information
Peida Zhao, Daisuke Kiriya, Angelica Azcatl, Chenxi Zhang, et al.. "Air Stable p-Doping of WSe2 by Covalent Functionalization" ACS Nano Vol. 8 Iss. 10 (2014) p. 10808 - 10814 ISSN: 1936-0851
Available at: http://works.bepress.com/santosh-kc/27/