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Updated: Jun 25, 2026
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Development and Functionalization of Electrolyte-Gated Graphene Field-Effect Transistor for Biomarker Detection
Published on: February 1, 2022
Photocurrent imaging and efficient photon detection in a graphene transistor
Fengnian Xia1, Thomas Mueller, Roksana Golizadeh-Mojarad
1IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, USA. fxia@ibm.com
Nano Letters
|February 11, 2009
Summary
This study reveals that metal contacts significantly influence graphene transistor channels, affecting most of the channel length. This metal-graphene interaction enables efficient light detection in the resulting p-n junctions.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Graphene transistors are promising electronic devices.
- Understanding metal-graphene contact effects is crucial for device performance.
- Photocurrent generation in graphene is an area of active research.
Purpose of the Study:
- To measure the channel potential profile of a graphene transistor.
- To investigate the influence of metal contacts on the graphene channel potential.
- To characterize the photoresponse of graphene p-n junctions.
Main Methods:
- Utilized scanning photocurrent imaging to map channel potential.
- Measured potential barriers at metal-graphene interfaces.
- Analyzed device behavior under varying gate biases and light illumination.
Main Results:
- Metal contacts significantly impact the channel potential, extending over a third of the channel length.
- A p-n-p channel is formed in graphene beyond the Dirac point voltage.
- An external responsivity of 0.001 A/W was achieved at the graphene p-n junctions.
Conclusions:
- Metal-graphene interactions dominate the channel potential in graphene transistors.
- The formation of p-n junctions enables efficient photodetection in single-layer graphene.
- Graphene's unique electronic properties can be harnessed for sensitive photodetectors.
