Abstract
We investigate the excitonic dynamics in MoSe2 monolayer and bulk samples by femtosecond transient absorption. Excitons are resonantly injected by a 750-nm and 100-fs laser pulse, and are detected by measuring a differential reflection of a probe pulse tuned in the range 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 a bulk sample under comparable conditions. We also observe the saturated absorption induced by excitons in both monolayers and the bulk in the differential reflection measurements, which indicates their potential applications as saturable absorbers.
Description
This is the published version. Copyright ©2014 American Physical Society
Citation
Kumar, Nardeep, Qiannan Cui, Frank Ceballos, Dawei He, Yongsheng Wang, and Hui Zhao. "Exciton-exciton Annihilation in MoSe 2 Monolayers." Phys. Rev. B Physical Review B 89.12 (2014). http://dx.doi.org/10.1103/PhysRevB.89.125427