Electrical Tuning of Exciton–Plasmon Polariton Coupling in Monolayer MoS₂ Integrated with Plasmonic Nanoantenna Lattice

Abstract

Active control of light-matter interactions in semiconductors is critical for realizing next generation optoelectronic devices with real-time control of the system's optical properties and hence functionalities via external fields. The ability to dynamically manipulate optical interactions by applied fields in active materials coupled to cavities with fixed geometrical parameters opens up possibilities of controlling the lifetimes, oscillator strengths, effective mass, and relaxation properties of a coupled exciton-photon (or plasmon) system. Here, we demonstrate electrical control of exciton-plasmon coupling strengths between strong and weak coupling limits in a two-dimensional semiconductor integrated with plasmonic nanoresonators assembled in a field-effect transistor device by electrostatic doping. As a result, the energy-momentum dispersions of such an exciton-plasmon coupled system can be altered dynamically with applied electric field by modulating the excitonic properties of monolayer MoS arising from many-body effects. In addition, evidence of enhanced coupling between charged excitons (trions) and plasmons was also observed upon increased carrier injection, which can be utilized for fabricating Fermionic polaritonic and magnetoplasmonic devices. The ability to dynamically control the optical properties of a coupled exciton-plasmonic system with electric fields demonstrates the versatility of the coupled system and offers a new platform for the design of optoelectronic devices with precisely tailored responses.

Strong Light–Matter Interactions Enabled by Polaritons in Atomically Thin Materials

“…To illustrate this, in Figure we provide a cursory overview of a number of hybrid metal–TMDCs systems exhibiting strong plasmon–exciton interactions. In most cases, the experimental setup consists in hybrid systems composed by atomically thin TMDCs in conjunction with plasmonic resonators, such as metallic nanoparticles with various shapes, nanoparticle‐on‐a‐mirror (NPoM) geometries, plasmonic crystals, as well as plasmonic lattices . A significant number of such plasmonic cavities are based on chemically grown metallic nanoparticles; this is motivated by the high‐quality (up to the single‐crystalline level) and extremely low surface roughness presented by these nanoparticles, which naturally yield plasmonic resonances with smaller linewidths.…”

Recent Advances in Quantum Effects of 2D Materials

“…Constructing a strong coupling system requires the quantum emitter with large transition momentum, which perfectly matches the advantage of strong excitonic effect in 2DLMs . Therefore, with the employment of 2DLMs, numbers of investigations with novel observations in the field of strong coupling are performed . Figure c illustrates the representative strong coupling systems constructed by 2DLMs and plasmonic nanocavities, where the TMDs together with a single plasmonic nanostructure or the nanoparticle on nanofilm structure are chosen .…”

Recent Progress on Exciton Polaritons in Layered Transition‐Metal Dichalcogenides

“…The yellow, green, and blue dashed lines mark the energies of uncoupled neutral A excitons (A 0 ), trions (A − ), and localized plasmon resonances, respectively. c) Reproduced with permission . Copyright 2017, American Chemical Society.…”

“…Gate tuning has also been demonstrated in a variety of hybrid polaritons such as PEPs and hybrid organic‐inorganic EPs . In the former case, PEPs were generated by coupling excitons in MoS 2 with localized plasmon resonance modes in silver nanodisk arrays (device structure similar to that of Figure a).…”

“…In the former case, PEPs were generated by coupling excitons in MoS 2 with localized plasmon resonance modes in silver nanodisk arrays (device structure similar to that of Figure a). Figure c presents the low‐temperature (77 K) angle‐resolved differential reflectance spectroscopy data of such a device (Figure a) taken at two different gate voltages (other voltages are given in the original paper), where dispersion properties of PEPs were visualized. At zero gate voltage ( V g = 0), photons couple with the charge‐neutral A excitons (A 0 , yellow dashed line) and the plasmon resonance mode (blue dashed line), so three polaritonic branches are observed (left panel of Figure c).…”