Room‐Temperature Remote Optical Probing of Interlayer Exciton Transport in Van Der Waals Heterostructures

Interlayer excitons in transition metal dichalcogenide (TMD) heterostructures feature long lifetime and superior transport properties, yet their room‐temperature optical tracking remains challenging due to weak emission. Here, remote optical probing of interlayer exciton transport in a TMD heterostructure at room temperature is demonstrated. Optically generated interlayer excitons diffuse through the heterostructure and dissociate at boundaries, where liberated carriers further migrate into monolayers and recombine with native charges to give bright intralayer emission. With the intralayer emission as a remote optical probe, unique properties of interlayer exciton transport are observed including the characteristic decay length of ≈4.5 µm, the power‐dependent phase transition between exciton gas and electron‐hole plasma, the thermally activated transport enhancement, and the fast diffusivity of ≈2100 cm2 s−1. The research offers a new route for the study of interlayer exciton transport with enhanced visibility, which paves the way for room‐temperature exciton transistors and circuits.