FIP Seminar: Tailoring light-matter interaction in 2D semiconductors using plasmonic nanocavities

Mar 22

Wednesday, March 22, 2017

12:00 pm - 1:00 pm
Hudson Hall 125

Presenter

Jiani Huang, Chambers Scholar, Department of Physics, Duke University

Controlling the interaction between light and matter is critical for the performance of optoelectronic and nanophotonic devices. Two-dimensional transition metal dichalcogenides (TMDCs) offers an ideal platform for a wide range of applications due to their remarkable optical properties. However, atomically thin TMDC monolayers suffer from weak light absorption (~3 %) and low photoluminescence (PL) quantum yield (~0.4 %). Furthermore, among the complex excitonic states of monolayer TMDCs, the B exciton emission is inherently weak compared to the dominant A exciton emission. In this talk, I will describe our recent experiments utilizing tunable plasmonic nanocavities, where emitters are sandwiched in a sub-10-nm dielectric gap between a metallic film and colloidally synthesized silver nanocubes. When emitters are embedded in the gap region, the spontaneous emission rate enhancements can be exceeding 1,000 times while maintaining high quantum efficiency (>50 %) and directional emission [Akselrod et al. Nature Photonics 8, 835 (2014)]. Incorporating semiconductor quantum dots into the plasmonic cavity enable ultrafast spontaneous emission with emission rates exceeding 90 GHz [Hoang et al. Nature Communications 6, 7788 (2015)]. When MoS2 monolayers are integrated into the plasmonic nanocavities with tunable plasmon resonances, we observe a 1,200-fold enhancement for A exciton emission and a 6,100-fold enhancement for B exciton emission [Huang et al. Submitted (2017)].

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Contact

Burns, August
660-5598
august.burns@duke.edu