Photoconductivity spectroscopy of epitaxial germanane devices

POSTER

Abstract

Germanane, a 2D sheet of hydrogen terminated germanium atoms, has recently generated a great deal of interest. Unlike graphene, which has been the focus of 2D materials for almost a decade, germanane has a direct band gap ($\sim$ 1.5 eV) and strong spin-orbit coupling. Additionally, it is predicted that changing the surface functionalization of germanane will allow tuning of the band gap, which makes it promising for electronic and opto-electronic applications. Here, we investigate wavelength dependent absorption and transport properties of optically excited carriers via photoconductivity on germanane. Samples with thicknesses ranging from several atomic layers up to 250 nm have been studied. We observe an absorption edge as a function of wavelength, as expected for a semiconducting material. There appears to be a small shift to shorter wavelengths for thinner samples. The dependence on intensity and temperature are also investigated, as well as the bias dependence. These results have implications for the use of germanane in future applications.

Authors

  • Elizabeth Bushong

    • The Ohio State University

  • Yunqiu Kelly Luo

    • Department of Physics, Ohio State University
    • The Ohio State University

  • Jeremiah van Baren

    • University of California Riverside
    • University of California, Riverside

  • Walid Amamou

    • University of California, Riverside

  • Patrick Odenthal

    • University of California, Riverside, Dept of Physics
    • University of California, Riverside

  • Dante O'Hara

    • University of California Riverside
    • University of California, Riverside
    • Univ of California - Riverside

  • Igor Pinchuk

    • The Ohio State University

  • Jyoti Katoch

    • Department of Physics, The Ohio State University, Columbus, OH 43210
    • The Ohio State University

  • Adam Anmed

    • The Ohio State University
    • Ohio State Univ - Columbus

  • Roland Kawakami

    • Department of Physics, Ohio State University; Department of Physics and Astronomy, University of California, Riverside
    • Department of Physics, The Ohio State University, Columbus, OH 43210; Department of Physics and Astronomy, University of California, Riverside, CA
    • The Ohio State University
    • The Ohio State University; University of California, Riverside