Interface excitons at lateral heterojunctions in monolayer semiconductors

Abstract

We study the interface exciton at lateral type II heterojunctions of monolayer transition metal dichalcogenides (TMDs), where the electron and hole prefer to stay at complementary sides of the junction. We find that the 1D interface exciton has giant binding energy in the same order as 2D excitons in pristine monolayer TMDs although the effective radius (electron-hole seperation) of interface exciton is much larger than that of 2D excitons. The binding energy, exciton radius and optical dipole strongly depends on the band offset at the junction. The inter-valley coupling induced by the electron-hole Coulomb exchange interaction and the quantum confinement effect at interface of a closed triangular shape are also investigated. Small triangles realize 0D quantum dot confinement of excitons, and we find a transition from non-degenerate ground state to degenerate ones when the size of the triangle varies. Our findings may facilitate the implementation of the optoelectronic devices based on the lateral heterojunction structures in monolayer semiconductors.

16 pages, 14 figures

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Cited by in corpus (14)

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• Exciton optics, dynamics and transport in atomically thin semiconductors
• Interface engineering of charge-transfer excitons in 2D lateral heterostructures
• Lateral heterostructures and one-dimensional interfaces in 2D transition metal dichalcogenides
• Exciton spectroscopy and diffusion in MoSe2-WSe2 lateral heterostructures encapsulated in hexagonal boron nitride
• Lateral Interfaces of Transition Metal Dichalcogenides: A Stable Tunable One-Dimensional Physics Platform
• Charged exciton kinetics in monolayer MoSe${}_2$ near ferroelectric domain walls in periodically poled LiNbO${}_3$
• Impact of charge transfer excitons on unidirectional exciton transport in lateral TMD heterostructures
• Excitonic Tonks-Girardeau and charge-density wave phases in monolayer semiconductors
• Quantum Confined Luminescence in Two dimensions
• Two dimensional semiconductors: optical and electronic properties
• Tuning of exciton type by environmental screening
• Non-Equilibrium First-Order Exciton Mott Transition at Monolayer Lateral Heterojunctions Visualized by Ultrafast Microscopy
• Interface Dark Excitons at Sharp Lateral Two-Dimensional Heterostructures