Room temperature dynamical control and electroluminescence from microcavity polaritons in monolayer transitional metal dichalcogenides*

We demonstrate modulation of exciton-photon interaction in strong coupling regime showing polariton branches at room temperature in monolayer WS₂ field effect transistor embedded inside a microcavity. Transitions from strong to weak coupling happens when WS₂ becomes electron doped under gating due to reduction in oscillator strength of the excitons arising from decreased Coulomb interaction. For polariton electroluminescence from a monolayer WS₂ at room temperature we incorporate a tunnel field effect transistor with graphene-hBN-WS₂-hBN-graphene van der Waal heterostructure inside the microcavity. Injected electrons and holes tunnel through hBN barrier and recombine in the WS₂ resulting in luminescence and shows clear polariton branches. Our findings with these new class of materials pave a novel way to realize low energy optoelectronic switches and possibly room temperature based polariton lasers through electrically controlled polariton luminescence.