Exciton dynamics in atomically thin MoS2: Interexcitonic interaction and broadening kinetics

Article

关键词: TRANSIENT ABSORPTION-SPECTRA;    REGENERATIVE AMPLIFIER;    PHOTOEXCITED CARRIERS;    BLUE-SHIFT;    QUANTUM;    FEMTOSECOND;    LAYER;    SEMICONDUCTOR;    IDENTIFICATION;    RELAXATION;   

DOI  :  10.1103/PhysRevB.88.075434

来源: SCIE

【 摘 要 】

We report ultrafast pump-probe spectroscopy examining exciton dynamics in atomically thin MoS2. Spectrally and temporally resolved measurements are performed to investigate the interaction dynamics of two important direct-gap excitons (A and B) and their associated broadening kinetics. The two excitons show strongly correlated interexcitonic dynamic, in which the transient blue-shifted excitonic absorption originates from the internal A-B excitonic interaction. The observed complex spectral response is determined by the exciton collision-induced linewidth broadening; the broadening of the B-exciton linewidth in turn lowers the peak spectral amplitude of the A exciton. Resonant excitation at the B-exciton energy reveals that interexcitonic scattering plays a more important role in determining the broadening kinetics than free-carrier scattering.

【 授权许可】

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