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Difference in gating and doping effects on the band gap in bilayer graphene
Takaki Uchiyama1, Hidenori Goto2, Hidehiko Akiyoshi1
1Research Institute for Interdisciplinary Science, Okayama University, Okayama, 700-8530, Japan.
Scientific Reports
|September 14, 2017
Summary
Electron/hole doping of bilayer graphene (BLG) can open a band gap, but results are variable. This study highlights key differences between electric field gating and carrier doping for controlling BLG electronic properties.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Bilayer graphene (BLG) exhibits tunable electronic properties via an electric field, enabling band gap opening for electronics.
- Gating and carrier doping are two methods to induce electric fields in BLG.
Purpose of the Study:
- To investigate if electron/hole doping can induce the electric field necessary to open a band gap in BLG.
- To compare the efficacy of carrier doping versus electric field gating for band gap generation in BLG.
Main Methods:
- Measuring the temperature dependence of conductivity in BLG devices.
- Utilizing electron-donor self-assembled monolayers (SAMs) and electron-acceptor molecules for doping.
- Fabricating and testing multiple BLG devices with varying doping configurations.
Main Results:
- Some BLG devices exhibited a measurable band gap, while others did not.
- The variability in results suggests that the structure of self-assembled monolayers (SAMs) influences electric field configuration and electronic properties.
- Demonstrated essential differences in band gap generation between electric field gating and carrier doping.
Conclusions:
- Carrier doping using adsorbates is a less reliable method for opening a band gap in BLG compared to electric field gating.
- The structural variability of SAMs poses challenges for consistent band gap induction via doping.
- Understanding these differences is crucial for designing future graphene-based electronic devices.
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