Defect-induced modification of low-lying excitons and valley selectivity in monolayer transition metal dichalcogenides

Abstract

We study the effect of point-defect chalcogen vacancies on the optical properties of monolayer transition metal dichalcogenides using ab initio GW and Bethe-Salpeter equation calculations. We find that chalcogen vacancies introduce unoccupied in-gap states and occupied resonant defect states within the quasiparticle continuum of the valence band. These defect states give rise to a number of strongly-bound defect excitons and hybridize with excitons of the pristine system, reducing the valley-selective circular dichroism. Our results suggest a pathway to tune spin-valley polarization and other optical properties through defect engineering.

References in corpus (17)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Valley polarization in MoS2 monolayers by optical pumping
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Quasiparticle band structures and optical properties of strained monolayer MoS2 and WS2
• Exciton Binding Energy of Monolayer WS2
• Probing excitonic states in ultraclean suspended two-dimensional semiconductors by photocurrent spectroscopy
• Truncation of Periodic Image Interactions for Confined Systems
• Exciton band structure of monolayer MoS2
• Ultrafast Manipulation of Valley Pseudospin
• Coupling of excitons and defect states in boron-nitride nanostructures
• Gate controlled spin-valley locking of resident carriers in WSe2 monolayers
• Non-uniform sampling schemes of the Brillouin zone for many-electron perturbation-theory calculations in reduced dimensionality
• Substrate screening effects on the quasiparticle band gap and defect charge transition levels in MoS${}_2$
• Electronic and Optical Properties of Vacancy Defects in Transition Metal Dichalcogenides
• Opto-valleytronic imaging of atomically thin semiconductors
• Symmetry-forbidden intervalley scattering by atomic defects in monolayer transition-metal dichalcogenides

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• First-principles computational methods for quantum defects in two-dimensional materials: A perspective
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