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A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics
Published on: August 28, 2018
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Why Two-Dimensional Semiconductors Generally Have Low Electron Mobility
Long Cheng1, Chenmu Zhang1, Yuanyue Liu1
1Texas Materials Institute and Department of Mechanical Engineering and The University of Texas at Austin, Austin, Texas 78712, USA.
Physical Review Letters
|November 6, 2020
Summary
The universally low electron mobility in two-dimensional (2D) semiconductors is due to a high "density of scatterings," an intrinsic property of these materials. This finding helps explain limitations in 2D semiconductor electronics.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanoscience
Background:
- Two-dimensional (2D) semiconductors are promising for next-generation electronics.
- Current 2D semiconductors exhibit lower room-temperature electron mobility than bulk silicon.
- The reasons for this mobility limitation remain poorly understood.
Purpose of the Study:
- To investigate the underlying physics behind the low electron mobility in 2D semiconductors.
- To identify intrinsic factors limiting electron mobility in these materials.
- To develop a descriptor for assessing 2D semiconductor mobility.
Main Methods:
- Utilized first-principles calculations.
- Reformulated transport equations to quantify mobility-determining factors.
- Analyzed electron and phonon band structures.
Main Results:
- Identified a high "density of scatterings" as the primary cause of low electron mobility in 2D semiconductors.
- Demonstrated that this high scattering density is intrinsic to 2D materials with parabolic electron bands.
- Showed that scattering density can be determined solely from electron and phonon band structures.
Conclusions:
- The universally low electron mobility in 2D semiconductors is fundamentally linked to their intrinsic scattering density.
- This research provides a new understanding of mobility limitations in 2D electronic materials.
- The proposed descriptor allows for rapid assessment of potential 2D semiconductor mobility.
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