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arXiv · 1311.1079

Exciton-exciton annihilation in MoSe2 monolayers

Nardeep Kumar·Qiannan Cui·Frank Ceballos·Dawei He·Yongsheng Wang·Hui Zhao
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Abstract

We investigate the excitonic dynamics in MoSe2 monolayer and bulk samples by femtosecond transient absorption microscopy. Excitons are resonantly injected by a 750-nm and 100-fs laser pulse, and are detected by a probe pulse tuned in the range of 790 - 820 nm. We observe a strong density-dependent initial decay of the exciton population in monolayers, which can be well described by the exciton-exciton annihilation. Such a feature is not observed in the bulk under comparable conditions. We also observe the saturated absorption induced by exciton phase-space filling in both monolayers and the bulk, which indicates their potential applications as saturable absorbers.

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Nardeep Kumar, Qiannan Cui, Frank Ceballos, Dawei He, Yongsheng Wang, Hui Zhao. 2013-11-05. Exciton-exciton annihilation in MoSe2 monolayers. https://doi.org/10.1103/physrevb.89.125427

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