Ferroelectric Tuning of Excitons in Sc2CO2/WSe2 Heterostructures

Abstract

Van der Waals heterostructures serve as ideal platforms for regulating exciton states. The introduction of ferroelectric materials has provided a new strategy for heterostructure exciton engineering. In this study, the electronic structures and excitonic optical properties of ferroelectric-based heterostructure Sc₂CO₂↓/WSe₂ and Sc₂CO₂↑/WSe₂ with different out-of-plane polarization directions have been investigated by the GW+BSE formalism. The findings show that out-of-plane polarization can realize the transition of heterostructure band alignment from Type I to Type II by regulating the band structure of the adsorbed layer WSe₂, significantly enhancing carrier separation efficiency. More importantly, changing the out-of-plane polarization direction enables dynamic regulation of the bright-dark attributes of heterostructure exciton states, achieving an optically switchable mechanism analogous to binary ″0″ and ″1″. Additionally, out-of-plane polarization exhibits significant regulatory effects on the optical absorption characteristics and radiative lifetimes of excitons. This study not only clarifies the effective modulation of ferroelectric polarization direction on the electronic structures of heterostructure but also reveals its unique advantages in manipulating the excitation behavior of optoelectronic devices.