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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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Programmable Interfacial Band Configuration in WS2/Bi2O2Se Heterojunctions
Hanwen Zhang1,2, Jianhui Fu3, Alexandra Carvalho4
1Joint School of the National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China.
ACS Nano
|June 18, 2024
Summary
Researchers engineered tunable band alignments in transition-metal dichalcogenide (TMD) heterojunctions by varying Bi2O2Se thickness. This allows for controlled fluorescence patterning, advancing photonic applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Van der Waals heterojunctions (TMDs) are key for light manipulation.
- Band alignment (type-I vs. type-II) dictates light-material interactions.
- Tuning band alignment without changing materials is challenging.
Purpose of the Study:
- To develop a novel method for engineering interfacial band configurations in WS2/Bi2O2Se heterojunctions.
- To demonstrate the ability to tune band alignment from type-I to type-II and back by controlling Bi2O2Se thickness.
- To achieve localized fluorescence patterning via focused laser beam (FLB) manipulation.
Main Methods:
- Utilized Bi2O2Se with thickness-dependent band gap as the bottom layer in WS2/Bi2O2Se heterojunctions.
- Varied Bi2O2Se thickness from monolayer to multilayer to tune band alignment.
- Employed steady-state and transient spectroscopy, alongside density functional theory (DFT) calculations for verification.
- Used focused laser beam (FLB) to create localized fluorescence micropatterns.
Main Results:
- Successfully tuned the band alignment from type-I to type-II and back to type-I by increasing Bi2O2Se thickness.
- Verified band architecture conversion through spectroscopic and computational methods.
- Demonstrated a sophisticated band architecture with both fluorescence-quenched and fluorescence-recovered regions in a single sample.
- Achieved predesigned localized fluorescence micropatterns on WS2 via FLB programming.
Conclusions:
- The study presents an innovative strategy for engineering interfacial band configurations in TMD heterojunctions.
- Thickness control of Bi2O2Se offers a versatile method for tuning band alignment.
- This approach enables precise control over optical properties, paving the way for multifunctional photonic devices.
- The developed band architecture design strategy significantly advances the potential of TMD heterojunctions.
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