Observation of rapid exciton-exciton annihilation in monolayer molybdenum disulfide

Dezheng Sun; Yi Rao; Georg A Reider; Gugang Chen; Yumeng You; Louis Brézin; Avetik R Harutyunyan; Tony F Heinz

doi:10.1021/nl5021975

Observation of rapid exciton-exciton annihilation in monolayer molybdenum disulfide

Nano Lett. 2014 Oct 8;14(10):5625-9. doi: 10.1021/nl5021975. Epub 2014 Sep 9.

Authors

Dezheng Sun¹, Yi Rao, Georg A Reider, Gugang Chen, Yumeng You, Louis Brézin, Avetik R Harutyunyan, Tony F Heinz

Affiliation

¹ Departments of Physics and Electrical Engineering, Columbia University , New York, New York 10027, United States.

PMID: 25171389
DOI: 10.1021/nl5021975

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.

Keywords: MoS2; exciton dynamics; exciton−exciton annihilation; transient absorption spectroscopy.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.