title: Observation of rapid exciton-exciton annihilation in monolayer molybdenum disulfide.
abstract: Monolayer MoS2 is a direct-gap two-dimensional semiconductor that exhibits strong electron-hole interactions, leading to the formation of stable excitons and trions. Here we report the existence of efficient exciton-exciton annihilation, a four-body interaction, in this material. Exciton-exciton annihilation was identified experimentally in ultrafast transient absorption measurements through the emergence of a decay channel varying quadratically with exciton density. The rate of exciton-exciton annihilation was determined to be (4.3 ± 1.1) × 10(-2) cm(2)/s at room temperature.
authors.affiliation: Departments of Physics and Electrical Engineering, Columbia University , New York, New York 10027, United States.
authors.forename: Dezheng
authors.initials: D
authors.lastname: Sun
authors.forename: Yi
authors.initials: Y
authors.lastname: Rao
authors.forename: Georg A
authors.initials: GA
authors.lastname: Reider
authors.forename: Gugang
authors.initials: G
authors.lastname: Chen
authors.forename: Yumeng
authors.initials: Y
authors.lastname: You
authors.forename: Louis
authors.initials: L
authors.lastname: Brézin
authors.forename: Avetik R
authors.initials: AR
authors.lastname: Harutyunyan
authors.forename: Tony F
authors.initials: TF
authors.lastname: Heinz
keywords: MoS2; exciton dynamics; exciton−exciton annihilation; transient absorption spectroscopy