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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Highly tunable charge transport in layer-by-layer assembled graphene transistors
Hyunmin Hwang1, Piljae Joo, Moon Sung Kang
1Department of Organic Materials and Fiber Engineering, Soongsil University, Seoul 156-743, Korea.
ACS Nano
|February 9, 2012
Summary
Researchers developed a new method to control electrical properties in graphene transistors. By adjusting the layers of reduced graphene oxide, they achieved tunable ambipolar or unipolar charge transport, enabling new electronic device applications.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Graphene field-effect transistors (GFETs) are crucial for advanced electronics.
- Controlling charge transport properties in GFETs is essential for device optimization.
- Layer-by-layer assembly offers a route to engineer graphene-based materials.
Purpose of the Study:
- To demonstrate a controlled method for tuning charge transport in GFETs.
- To investigate the effect of multilayer reduced graphene oxide films on transistor behavior.
- To explore the potential for solution-processable graphene electronics.
Main Methods:
- Alternating layer-by-layer assembly of charged graphene oxide.
- Thermal reduction of graphene oxide multilayers.
- Characterization using X-ray photoemission spectroscopy, Raman spectroscopy, and ToF-SIMS.
- Temperature-dependent charge transport measurements.
Main Results:
- Achieved tunable ambipolar and unipolar (n-type and p-type) transport in GFETs.
- Demonstrated that the number of graphene oxide bilayers controls electrical behavior.
- Identified nitrogen doping via functional groups of positively charged graphene oxide during thermal reduction.
Conclusions:
- Nitrogen incorporation during thermal reduction, dependent on bilayer count, dictates charge transport.
- This method provides versatile control over graphene multilayer transistor characteristics.
- The findings promote applications of graphene multilayers in solution-processable electronic devices.
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