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Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
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Field-Dependent Band Structure Measurements in Two-Dimensional Heterostructures
Paul V Nguyen1, Natalie C Teutsch2, Nathan P Wilson1
1Department of Physics, University of Washington, Seattle, Washington 98195, United States.
Nano Letters
|December 1, 2021
Summary
Electric fields applied via electrostatic gating can tune the band alignment in van der Waals heterostructures. This study directly measures these crucial band structure changes in graphene/transition metal dichalcogenide systems.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Van der Waals heterostructures are key components in advanced electronic and optoelectronic devices.
- Electric fields significantly alter their band structure, impacting device performance.
- Direct measurement of these field-induced band changes has been challenging.
Purpose of the Study:
- To directly measure electric field-induced changes in band alignment within van der Waals heterostructures.
- To correlate these band shifts with electrostatic gating effects.
- To validate a simple model for understanding band structure modifications in these systems.
Main Methods:
- Fabrication of van der Waals heterostructures using graphene, monolayer transition metal dichalcogenides (WSe2 or MoSe2), boron nitride, and graphite.
- Utilizing spatially resolved angle-resolved photoemission spectroscopy (ARPES).
- Applying electrostatic gating via a graphite gate to induce electric fields.
Main Results:
- Observed shifts in semiconductor band alignment relative to graphene up to 0.2 eV.
- Demonstrated that electrostatic gating effectively modulates the band structure.
- The experimental results align with a model assuming minimal material hybridization.
Conclusions:
- Spatially resolved ARPES is a powerful technique for probing field-induced band structure modifications in heterostructures.
- Electrostatic gating provides a tunable knob for controlling band alignment in graphene-based van der Waals devices.
- The findings support a simplified understanding of band behavior in these layered materials.
Keywords:
Two-dimensional materialsangle resolved photoemission spectroscopytwo-dimensional heterostructurestwo-dimensional semiconductorsMore Related Videos
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