Mapping nanoscale energy transport in 2D transition metal dichalcogenides with stroboscopic scattering microscopy

Abstract

Characterizing the intrinsic properties of low-dimensional transition metal dichalcogenides (TMDCs) is necessary for explaining how their novel properties arise and are modified by their local environment. Excitations in few-layer TMDCs and heterostructures are difficult to probe directly because of their low photoluminescence quantum yield. With time-resolved elastic scattering microscopy, we spatiotemporally resolve both in-plane and out-of-plane nanoscale transport in several TMDC species and architectures as a function of layer thickness and pump-induced carrier density. We directly observe interlayer exciton transport in TMDC heterostructures and find that these species diffuse an order of magnitude farther and faster than excitations do in their isolated counterparts.