Quenched Excitons in WSe₂/-RuCl₃ Heterostructures Revealed by Multimessenger Nanoscopy

We investigate heterostructures composed of monolayerWSe(2) stacked on alpha-RuCl3 using a combinationof Terahertz(THz) and infrared (IR) nanospectroscopy and imaging, scanning tunnelingspectroscopy (STS), and photoluminescence (PL). Our observations revealitinerant carriers in the heterostructure prompted by charge transferacross the WSe2/alpha-RuCl3 interface. LocalSTS measurements show the Fermi level is shifted to the valence bandedge of WSe2 which is consistent with p-type doping andverified by density functional theory (DFT) calculations. We observeprominent resonances in near-IR nano-optical and PL spectra, whichare associated with the A-exciton of WSe2. We identifya concomitant, near total, quenching of the A-exciton resonance inthe WSe2/alpha-RuCl3 heterostructure. Ournano-optical measurements show that the charge-transfer doping vanisheswhile excitonic resonances exhibit near-total recovery in "nanobubbles",where WSe2 and alpha-RuCl3 are separated bynanometer distances. Our broadband nanoinfrared inquiry elucidateslocal electrodynamics of excitons and an electron-hole plasmain the WSe2/alpha-RuCl3 system.