Charged Exciton Kinetics in Monolayer MoSe 2 near Ferroelectric Domain Walls in Periodically Poled LiNbO 3

• Published in: Nano letters 2021-01, Vol.21 (2), p.959-966
• Main Authors: Soubelet, Pedro, Klein, Julian, Wierzbowski, Jakob, Silvioli, Riccardo, Sigger, Florian, Stier, Andreas V, Gallo, Katia, Finley, Jonathan J
• Format: Article
• Language: English
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.0c03810

Monolayer semiconducting transition metal dichalcogenides are a strongly emergent platform for exploring quantum phenomena in condensed matter, building novel optoelectronic devices with enhanced functionalities. Because of their atomic thickness, their excitonic optical response is highly sensitive to their dielectric environment. In this work, we explore the optical properties of monolayer thick MoSe straddling domain wall boundaries in periodically poled LiNbO . Spatially resolved photoluminescence experiments reveal spatial sorting of charge and photogenerated neutral and charged excitons across the boundary. Our results reveal evidence for extremely large in-plane electric fields of ≃4000 kV/cm at the domain wall whose effect is manifested in exciton dissociation and routing of free charges and trions toward oppositely poled domains and a nonintuitive spatial intensity dependence. By modeling our result using drift-diffusion and continuity equations, we obtain excellent qualitative agreement with our observations and have explained the observed spatial luminescence modulation using realistic material parameters.