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Updated: Dec 17, 2025
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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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Type-II Interface Band Alignment in the vdW PbI2-MoSe2 Heterostructure.
Junting Xiao1, Lei Zhang2, Hui Zhou3
1Hunan Key Laboratory of Super-Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, P. R. China.
ACS Applied Materials & Interfaces
|July 1, 2020
Summary
Researchers fabricated van der Waals PbI2-MoSe2 heterostructures, revealing a type-II band alignment crucial for electronic device design. This scalable method offers insights into interfacial electronic structures.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Heterostructure interfaces are critical for the performance of electronic devices, particularly those involving two-dimensional (2D) atomically thin materials.
- Understanding energy band alignments at these interfaces is essential for optimizing device functionality.
Purpose of the Study:
- To comprehensively study van der Waals PbI2-MoSe2 heterostructures fabricated via in situ deposition.
- To determine the interface band alignment and electronic structure of these heterostructures.
- To provide a scalable fabrication method and insights for future device design.
Main Methods:
- Fabrication of PbI2-MoSe2 heterostructures using in situ PbI2 deposition on monolayer MoSe2.
- Characterization using scanning tunneling microscopy/spectroscopy (STM/S), atomic force microscopy (AFM), photoemission spectroscopy (PES), Raman spectroscopy, and photoluminescence (PL) spectroscopy.
- First-principles calculations to confirm band alignment.
Main Results:
- PbI2 exhibits quasi layer-by-layer epitaxial growth on MoSe2.
- A type-II interface band alignment was determined, with the conduction band minimum at PbI2 and the valence band maximum at MoSe2.
- Interfacial excitons were observed using temperature-dependent PL, confirming the type-II alignment.
Conclusions:
- The study successfully fabricated scalable PbI2-MoSe2 heterostructures.
- The confirmed type-II band alignment provides crucial insights into the electronic properties of these 2D heterostructures.
- These findings pave the way for advanced electronic and optoelectronic device designs utilizing 2D materials.
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