5 years ago

Solution-Processed Doping of Trilayer WSe2 with Redox-Active Molecules

Solution-Processed Doping of Trilayer WSe2 with Redox-Active Molecules
Eric M. Vogel, Siyuan Zhang, Seth R. Marder, Samuel Graham, Raghunath R. Dasari, Meng-Yen Tsai, Stephen Barlow, Xiaochu Ba, Philip M. Campbell, Alexey Tarasov
The development of processes to controllably dope two-dimensional semiconductors is critical to achieving next-generation electronic and optoelectronic devices. In this study, n- and p-doping of highly uniform large-area trilayer WSe2 is achieved by treatment with solutions of molecular reductants and oxidants. The sign and extent of doping can be conveniently controlled by the redox potential of the (metal−)organic molecules, the concentration of dopant solutions, and the treatment time. Threshold voltage shifts, the direction of which depends on whether a p- or n-dopant is used, and tunable channel current are observed in doped WSe2 field-effect transistors. Detailed physical characterization including photoemission (ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy) and Raman spectroscopy provides fundamental understanding of the underlying mechanism. The origin of the doping is the electron-transfer reactions between molecular dopants and 2D semiconductors and results in a shift of the Fermi level relative to the valence band due both to state filling/emptying and to large surface dipoles between the dopant ions and the oppositely charged WSe2. These two effects both contribute to large work function changes of up to ±1 eV.

Publisher URL: http://dx.doi.org/10.1021/acs.chemmater.7b01998

DOI: 10.1021/acs.chemmater.7b01998

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.