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Updated: Jun 28, 2026
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Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Interface Excitons in van der Waals Sandwich Heterostructures
Chao Zhang1,2, Yuting Li3, Wenwei Chen4
1School of Optoelectronic Science and Engineering and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.
ACS Nano
|June 26, 2026
Summary
Polarity engineering in van der Waals heterostructures enables precise control over interface excitons (IFXs). This strategy offers a robust route for designing advanced optoelectronic devices by tuning exciton properties.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Exciton engineering in van der Waals heterostructures (vdWHs) is crucial for advanced optoelectronics.
- Current methods often require precise stacking and are sensitive to moiré potentials.
Purpose of the Study:
- To demonstrate a polarity-engineering strategy for controlling excitonic properties in vdWHs.
- To investigate interface excitons (IFXs) in a γ-InSe/transition metal dichalcogenide/γ-InSe sandwich heterostructure.
Main Methods:
- Fabrication of a sandwich heterostructure using γ-InSe and transition metal dichalcogenides.
- First-principles calculations and Kelvin probe force microscopy to analyze interfacial charge transfer.
- Transient spectroscopy to study exciton dynamics and relaxation.
Main Results:
- Demonstrated IFXs with a linear Stark effect and an ultrasmall dipole moment (0.15 e·nm).
- Revealed asymmetric interfacial charge transfer driven by γ-InSe's inherent polarity.
- Observed nonmonotonic relaxation dynamics and signal reversal in transient spectroscopy, indicating pre-existing interfacial charge states.
Conclusions:
- Polarity engineering offers a versatile and robust method to tune exciton dipole moments, interlayer coupling, and relaxation dynamics in vdWHs.
- This approach provides new design strategies for next-generation excitonic and optoelectronic devices.
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