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Updated: Oct 21, 2025
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A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics
Published on: August 28, 2018
9.9K
Vertically stacked Bi2Se3/MoTe2 heterostructure with large band offsets for nanoelectronics
Lin Tao1,2, Bin Yao1,2, Qian Yue3
1State Key Lab of Superhard Material, and College of Physics, Jilin University, Changchun 130012, P. R. China. binyao@jlu.edu.cn.
Nanoscale
|September 9, 2021
Summary
We developed a new method to create large topological insulator nanosheets for advanced electronic devices. This tunneling heterostructure shows excellent performance in logic circuits and photodetection with ultralow dark current.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Two-dimensional (2D) material-based tunneling heterojunctions are promising for logic circuits and photodetection.
- Topological insulator (TI) materials like Bi2Se3 are underexplored in these heterostructures due to fabrication challenges.
- Mechanical exfoliation of TIs is difficult due to strong interlayer interactions.
Purpose of the Study:
- To develop a scalable method for fabricating large-scale topological insulator (Bi2Se3) nanosheets.
- To construct a novel broken-gap tunneling heterostructure using 2D materials.
- To investigate the optoelectrical performance and carrier transport mechanisms of the fabricated heterostructure.
Main Methods:
- Au-assisted exfoliation and non-destructive transfer for Bi2Se3 nanosheet fabrication.
- Dry-transfer method to combine 2H-MoTe2 and Bi2Se3 for heterostructure formation.
- Electrical and optical characterization, including current-voltage measurements and photoresponse analysis.
- Numerical solution of Poisson's equation to determine built-in potential and band alignment.
Main Results:
- Successfully fabricated large-scale Bi2Se3 thin nanosheets using an Au-assisted method.
- Demonstrated a novel 2H-MoTe2/Bi2Se3 broken-gap tunneling heterostructure with clear rectifying behavior (ambipolar-n device).
- Verified a built-in potential exceeding ~0.7 eV due to large band offsets.
- Achieved an ultralow dark current (~0.2 pA), high light/dark current ratio (~10^6), fast response time (21 ms), and high detectivity (7.2 × 10^11 Jones) at 405 nm visible light.
Conclusions:
- The Au-assisted method provides a universal route for fabricating topological insulator nanosheets.
- The novel van der Waals tunneling heterostructure exhibits excellent optoelectrical properties.
- This work opens new avenues for designing advanced 2D material-based tunneling devices for sensing and logic applications.
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