Stability and Exfoliation of Germanane: A Germanium Graphane Analogue
[Technical Report, Master's Thesis]
Ohio State University
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Graphenes success has shown that it is not only possible to create stable, single-atom thick sheets from a crystalline solid, but that these materials have fundamentally different properties than the parent material. We have synthesized for the first time, mm-scale crystals of a hydrogen-terminated germanium multilayered graphane analogue germanane, GeH from the topochemical deintercalation of CaGe2. This layered van der Waals solid is analogous to multilayered graphane CH. The surface layer of GeH only slowly oxidizes in air over the span of 5 months, while the underlying layers are resilient to oxidation based on X-ray Photoelectron Spectroscopy XPS and Fourier Transform Infrared Spectroscopy FTIR measurements. The GeH is thermally stable up to 75 deg. C, however, above this temperature amorphization and dehydrogenation begin to occur. These sheets can be mechanically exfoliated as single and few layers onto SiO2Si surfaces. This material represents a new class of covalently terminated graphane analogues and has great potential for a wide range of optoelectronic and sensing applications, especially since theory predicts a direct band gap of 1.53 eV and an electron mobility five times higher than that of bulk Ge.
- Physical Chemistry
- Solid State Physics