2022/04/20 by L. H. Fowler-Gerace, Fowler-Gerace, L. H., Zhiwen Zhou +5
Engineering · Materials Science · #2D Materials and Applications #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Molecular Junctions and Nanostructures #Perovskite Materials and Applications
paper · pdf · doi:10.48550/arxiv.2204.09760
openalex publication_date 2022/04/20 · openalex created_date 2023/02/14 · openalex updated_date 2026/07/28
Long lifetimes of spatially indirect excitons (IXs), also known as interlayer excitons, make possible long-range IX propagation. Van der Waals heterostructures composed of atomically thin layers of transition-metal dichalcogenides (TMDs) give an opportunity to realize excitons with high binding energies and provide a materials platform for the realization of both excitonic quantum phenomena and excitonic devices. Propagation of IXs in TMD heterostructures is intensively studied. However, in spite of long IX lifetimes, orders of magnitude longer than lifetimes of spatially direct excitons (DXs), a relatively short-range IX propagation with the 1/e decay distances d1/e up to few μm was reported in the studies of TMD heterostructures. The short-range of IX propagation originates from in-plane potentials, which localize excitons and suppress exciton transport. In particular, significant in-plane moiré potentials predicted in TMD heterostructures can cause an obstacle for IX propagation. In this work, we realize in a MoSe2/WSe2 heterostructure a macroscopically long-range IX propagation with d1/e reaching ∼ 100 μm. The strong enhancement of IX propagation is realized using an optical excitation resonant to DXs in the heterostructure. The strong enhancement of IX propagation originates from the suppression of IX localization and scattering and is observed in the quantum regime.