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Electrically Tunable Bandgaps in Bilayer MoS₂
Tao Chu1,2, Hesameddin Ilatikhameneh1, Gerhard Klimeck1
1School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.
Nano Letters
|November 13, 2015
Summary
Researchers demonstrated continuous bandgap tuning in bilayer molybdenum disulfide (MoS2) using electric fields. This electric field-controlled bandgap modulation in 2D semiconductors offers new possibilities for nanoelectronic and nanophotonic devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Artificial semiconductors enable advanced optoelectronics.
- Two-dimensional (2D) transition metal dichalcogenides (TMDs) offer tunable bandgaps for high-performance devices.
- The unique properties of layered TMDs allow for electric field modification of band structures.
Purpose of the Study:
- To demonstrate continuous bandgap tuning in bilayer MoS2.
- To explore the potential of electric field modulation for nanoelectronic and nanophotonic applications.
Main Methods:
- Fabrication of a dual-gated field-effect transistor (FET) using bilayer MoS2.
- Utilizing photoluminescence (PL) spectroscopy to measure bandgap changes.
- Employing Density Functional Theory (DFT) to calculate field-dependent band structures.
Main Results:
- Achieved continuous bandgap tuning in bilayer MoS2 via an applied electric field.
- Observed an interlayer direct bandgap transition as the mechanism for bandgap tunability.
- Demonstrated bandgap modulation approaching a semiconductor-to-metal transition.
Conclusions:
- Bilayer MoS2 exhibits significant electric field-induced bandgap tunability.
- This tunability is attributed to an interlayer direct bandgap transition.
- The findings open avenues for novel nanoelectronic and nanophotonic applications leveraging electric field-controlled bandgap modulation.
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