Strain-Modulated Interlayer Charge and Energy Transfers in MoS2/WS2 Heterobilayer
arXiv:2108.13573
Abstract
Excitonic properties in 2D heterobilayers are closely governed by charge transfer (CT) and excitonic energy transfer (ET) at van der Waals interfaces. Various means have been employed to modulate the interlayer CT and ET, including electrical gating and modifying interlayer spacing, but with limited extent in their controllability. Here, we report a novel method to modulate these transfers in MoS2/WS2 heterobilayer by applying compressive strain under hydrostatic pressure. Raman and photoluminescence measurements, combined with density functional theory calculations show pressure-enhanced interlayer interaction of the heterobilayer. Photoluminescence enhancement factor η of WS2 in heterobilayer decreases by five times up to ~4 GPa, suggesting a strong ET, whereas it increases by an order of magnitude at higher pressures and reaches almost unity, indicating enhanced CT. Theoretical calculations show that orbital switching in the conduction bands is responsible for the modulation of the transfers. Our findings provide a compelling approach towards effective mechanical control of CT and ET in 2D excitonic devices.
References in corpus (9)
- Observation of tightly bound trions in monolayer MoS2
- Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures
- Semiconductor-metal transition in semiconducting bilayer sheets of transition metal dichalcogenides
- Dynamic band structure tuning of graphene moiré superlattices with pressure
- Chemically Induced Transformation of CVD-Grown Bilayer Graphene into Single Layer Diamond
- Interfacial Charge Transfer Circumventing Momentum Mismatch at 2D van der Waals Heterojunctions
- Giant Thermal Conductivity Enhancement in Multilayer MoS2 under Highly Compressive Strain
- Tuning the van der Waals Interaction of Graphene with Molecules via Doping
- Pressure-Induced Metal-Insulator Transition in Twisted Bi-layer Graphene