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Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
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Interlayer Exciton Transport in MoSe2/WSe2 Heterostructures
Zidong Li, Xiaobo Lu, Darwin F Cordovilla Leon
1International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki 305-0044, Japan.
ACS Nano
|January 8, 2021
Summary
Moiré superlattices in transition metal dichalcogenide heterostructures act as diffusion barriers for interlayer excitons. This study quantifies this barrier, revealing temperature-activated exciton diffusivity dependent on twist angle.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Moiré superlattices in transition metal dichalcogenide (TMC) heterostructures create periodic potentials.
- These potentials influence the behavior of interlayer excitons, which are bound electron-hole pairs in different layers.
Purpose of the Study:
- To experimentally quantify the diffusion barrier for interlayer excitons in MoSe2/WSe2 heterostructures.
- To investigate the effect of moiré superlattice twist angle on exciton dynamics and energy transport.
Main Methods:
- Fabrication of hexagonal boron nitride-encapsulated MoSe2/WSe2 heterostructures with varying twist angles.
- Experimental measurements of interlayer exciton localization and diffusivity at different temperatures.
- Theoretical calculations, Monte Carlo simulations, and a three-level exciton dynamics model.
Main Results:
- Observed localization of interlayer excitons at low temperatures.
- Demonstrated temperature-activated exciton diffusivity that is dependent on the twist angle.
- Attributed exciton behavior to the periodic potentials generated by the moiré superlattice.
Conclusions:
- The moiré superlattice acts as a significant diffusion barrier for interlayer excitons.
- Twist angle engineering provides a method to control exciton dynamics and energy transport in TMC heterostructures.
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