Electrical suppression of all nonradiative recombination pathways in monolayer semiconductors

Abstract

Defects in conventional semiconductors substantially lower the photoluminescence (PL) quantum yield (QY), a key metric of optoelectronic performance that directly dictates the maximum device efficiency. Two-dimensional (2D) transition metal dichalcogenides (TMDCs), such as monolayer MoS2, often exhibit low PL QY for as-processed samples, which has typically been attributed to a large native defect density. We show that the PL QY of as-processed MoS2 and WS2 monolayers reaches near-unity when they are made intrinsic by electrostatic doping, without any chemical passivation. Surprisingly, neutral exciton recombination is entirely radiative even in the presence of a high native defect density. This finding enables TMDC monolayers for optoelectronic device applications as the stringent requirement of low defect density is eased.

References in corpus (3)

• Light-emitting diodes by bandstructure engineering in van der Waals heterostructures
• Strong interlayer coupling in van der Waals heterostructures built from single-layer chalcogenides
• Chloride Molecular Doping Technique on 2D Materials: WS2 and MoS2

Cited by in corpus (12)

• Inhibited nonradiative decay at all exciton densities in monolayer semiconductors
• Controllable p-type Doping of 2D WSe2 via Vanadium Substitution
• Collective Excitations in 2D Materials
• Exciton optics, dynamics and transport in atomically thin semiconductors
• Defect Engineering of Two-dimensional Molybdenum Disulfide
• Harnessing Exciton-Exciton Annihilation in Two-Dimensional Semiconductors
• Tuning exciton recombination rates in doped transition metaldichalcogenides
• Controlling relaxation dynamics of excitonic states in monolayer transition metal dichalcogenides WS2 through interface engineering
• Robustness of momentum-indirect interlayer excitons in MoS2/WSe2 heterostructure against charge carrier doping
• Coupling Spin Defects in a Layered Material to Nanoscale Plasmonic Cavities
• Efficient valley polarization of charged excitons and resident carriers in MoS2 monolayers by optical pumping
• Spatially Resolved Persistent Photoconductivity in MoS${}_2$-WS${}_2$ Lateral Heterostructures