DMI/MEMS Seminar Presented by Prof. Kevin Daniels

Abstract: Two-dimensional materials possess unique mechanical, optical, and electronic properties that can exceed those of their bulk crystal counterparts. For example, graphene, a two-dimensional material composed of a single layer of carbon atoms, exhibits exceptionally high carrier mobilities (~100,000 cm2/Vs), high surface area (2630 m2/g), and quasi-ballistic transport of carriers, making it an attractive material for various applications in electronics, optics, and sensing. In this talk, I will focus on the synthesis and applications of quasi-freestanding epitaxial graphene (QEG) on silicon carbide, grown from the sublimation of silicon from silicon carbide and the subsequent hydrogen passivation of silicon carbide substrate, for chemical and biological sensing, electron emission, and electrochemical material growth. I will discuss phenomena observed in QEG, from polarization-induced strain enabling the selective detection of very few copies of viruses like SARS-CoV-2, the virus responsible for COVID-19, to phonon-assisted electron emission, allowing emission of electrons at only 150°C, and the use of QEG as a substrate for the growth of 2D transition metal oxides. This work is enabled by and arises from the higher quality and single-crystal nature of epitaxial graphene compared to other growth graphene growth methods and the reduction in carrier scattering and electron-phonon coupling due to the quasi-freestanding nature of the QEG.