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Plasma-assisted Molecular Beam Epitaxy of N-polar InAlN-barrier High-electron-mobility Transistors
Published on: November 24, 2016
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Interlayer and Intralayer Excitons in AlN/WS2 Heterostructure
Claudio Attaccalite1,2, Maria Stella Prete3, Maurizia Palummo2,3
1Centre Interdisciplinaire de Nanoscience de Marseille UMR 7325 Campus de Luminy, CNRS/Aix-Marseille Université, CEDEX 9, 13288 Marseille, France.
Materials (Basel, Switzerland)
|December 11, 2022
Summary
We studied AlN/WS2 heterobilayers, finding type I band alignment and intralayer excitons similar to WS2. While not ideal for photocatalysis, AlN shows promise as a low-screening substrate for 2D optoelectronics.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Quantum Chemistry
Background:
- Van der Waals (vdW) heterostructures, particularly 2D semiconducting materials like Transition Metal Dichalcogenides (TMDs), are crucial for optoelectronics due to strong light-matter interactions.
- Group-III nitrides and TMDs are promising for applications in photocatalysis, photovoltaics, and flexible devices.
Purpose of the Study:
- Investigate the electronic and excitonic properties of the AlN/WS2 heterobilayer.
- Determine the band alignment and exciton characteristics.
- Analyze the influence of strain and AlN dielectric screening on electronic and optical properties.
Main Methods:
- First-principles ground and excited-state simulations.
- Analysis of band alignment, including spin-orbit and many-body interactions.
- Evaluation of strain and dielectric screening effects.
Main Results:
- The AlN/WS2 heterobilayer exhibits type I band alignment.
- Low-energy intralayer excitons are comparable to those in pristine WS2 monolayers.
- Strain and AlN dielectric screening significantly impact electronic and optical gaps.
Conclusions:
- AlN/WS2 is not favored for photocatalysis but AlN is a promising low-screening substrate for TMD-based optoelectronics.
- Accurate prediction of properties in TMD/nitride heterobilayers necessitates including spin-orbit and many-body interactions.
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