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Center for Nonlinear Studies |
Chemical exfoliation of layered van der Waals materials such as graphite and transition metal chalcogenides allow access to large quantities of atomically thin two-dimensional (2D) nanosheets suitable for energy-related technologies. Although these 2D materials have recently become popular, their fabrication via exfoliation of bulk crystals has been known for decades. For example, British chemist Brodie first exfoliated graphite into atomically thin oxidized form of graphene in 1859. In the case of layered transition metal dichalcogenides (LTMDs) such as MoS2, WS2, MoSe2, and WSe2, Canadian chemist Frindt et al. performed seminal work in the 1970s and ‘80s. We have revived these techniques to obtain chemically exfoliated 2D nanosheets with different compositions and utilized these materials in wide variety of electronic and energy applications. In the presentation, I will highlight some of our key contributions with graphene oxide (GO) and LTMD nanosheets. Specifically, I will present implementation of GO into transparent conductors of large area & flexible electronics and electrochemical devices, hermetic barriers for organic electronics, and demonstration of its unique properties of tunable photoluminescence. I will also present intriguing photoluminescence and catalytic properties of chemically exfoliated LTMDs, as well as utilization of “phase-engineering” approach that we gained from the chemical exfoliation processes of LTMDs to solve an important problem of reducing high contact resistance in electronic and optoelectronic devices. I will conclude by briefly mentioning the direction of research I intend to pursue with 2D materials.
Host: Mila Adamska