Disorder of excitons and trions in monolayer MoSe2

Jue Wang; Christina Manolatou; Yusong Bai; James Hone; Farhan Rana; X-Y Zhu

doi:10.1063/5.0108001

Disorder of excitons and trions in monolayer MoSe₂

J Chem Phys. 2022 Dec 7;157(21):211101. doi: 10.1063/5.0108001.

Authors

Jue Wang¹, Christina Manolatou², Yusong Bai¹, James Hone³, Farhan Rana², X-Y Zhu¹

Affiliations

¹ Department of Chemistry, Columbia University, New York, New York 10027, USA.
² School of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853, USA.
³ Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA.

PMID: 36511560
DOI: 10.1063/5.0108001

Abstract

The optical spectra of transition metal dichalcogenide monolayers are dominated by excitons and trions. Here, we establish the dependence of these optical transitions on the disorder from hyperspectral imaging of h-BN encapsulated monolayer MoSe₂. While both exciton and trion energies vary spatially, these two quantities are almost perfectly correlated, with spatial variation in the trion binding energy of only ∼0.18 meV. In contrast, variation in the energy splitting between the two lowest energy exciton states is one order of magnitude larger at ∼1.7 meV. Statistical analysis and theoretical modeling reveal that disorder results from dielectric and bandgap fluctuations, not electrostatic fluctuations. Our results shed light on disorder in high quality TMDC monolayers, its impact on optical transitions, and the many-body nature of excitons and trions.