Ultrafast Dynamics of Defect-Assisted Electron-Hole Recombination in Monolayer MoS2

Abstract

In this letter, we present non-degenerate ultrafast optical pump-probe studies of the carrier recombination dynamics in MoS${}_2$ monolayers. By tuning the probe to wavelengths much longer than the exciton line, we make the probe transmission sensitive to the total population of photoexcited electrons and holes. Our measurement reveals two distinct time scales over which the photoexcited electrons and holes recombine; a fast time scale that lasts $\sim$2 ps and a slow time scale that lasts longer than $\sim$100 ps. The temperature and the pump fluence dependence of the observed carrier dynamics are consistent with defect-assisted recombination as being the dominant mechanism for electron-hole recombination in which the electrons and holes are captured by defects via Auger processes. Strong Coulomb interactions in two dimensional atomic materials, together with strong electron and hole correlations in two dimensional metal dichalcogenides, make Auger processes particularly effective for carrier capture by defects. We present a model for carrier recombination dynamics that quantitatively explains all features of our data for different temperatures and pump fluences. The theoretical estimates for the rate constants for Auger carrier capture are in good agreement with the experimentally determined values. Our results underscore the important role played by Auger processes in two dimensional atomic materials.

arXiv comment25 pages, 10 figures

References in corpus (27)

• Atomically thin MoS2: A new direct-gap semiconductor
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Control of valley polarization in monolayer MoS2 by optical helicity
• Single-Layer MoS2 Phototransistors
• Observation of tightly bound trions in monolayer MoS2
• Grains and grain boundaries in highly crystalline monolayer molybdenum disulfide
• Integrated Circuits Based on Bilayer MoS2 Transistors
• Electrically Tunable Excitonic Light Emitting Diodes based on Monolayer WSe2 p-n Junctions
• Optoelectronics with electrically tunable PN diodes in a monolayer dichalcogenide
• Hopping Transport through Defect-induced Localized States in Molybdenum Disulfide
• Two-dimensional transition metal dichalcogenides under electron irradiation: defect production and doping
• Symmetry-dependent phonon renormalization in monolayer MoS2 transistor
• Electroluminescence in Single Layer MoS2
• Theory of Neutral and Charged Excitons in Monolayer Transition Metal Dichalcogenides
• Low-temperature photocarrier dynamics in monolayer MoS2
• Ultrafast Optical-Pump Terahertz-Probe Spectroscopy of the Carrier Relaxation and Recombination Dynamics in Epitaxial Graphene
• Novel High-Mobility Field-Effect Transistors Based on Transition Metal Dichalcogenides
• Measurement of the Optical Absorption Spectra of Epitaxial Graphene from Terahertz to Visible
• Band-Like Transport in High Mobility Unencapsulated Single-Layer MoS2 Transistors
• Carrier and polarization dynamics in monolayer MoS2
• Stability and dopability of native defects and group-V and -VII impurities in single-layer MoS2
• Absorption of Light by Excitons and Trions in Monolayers of Metal Dichalcogenide MoS${}_2$: Experiments and Theory
• Ultrafast Relaxation Dynamics of Hot Optical Phonons in Graphene
• Ultrafast and spatially resolved studies of charge carriers in atomically-thin molybdenum disulfide
• Exciton dynamics in atomically thin MoS2: inter-excitonic interaction and broadening kinetics
• Line Defects in Molybdenum Disulfide Layers
• Effect of Point Defects on the Optical and Transport Properties of MoS2 and WS2

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