Photo-Thermoelectric Effect at a Graphene Interface Junction

We investigate the optoelectronic response of a graphene interface junction, formed with bilayer and single-layer graphene, by photocurrent (PC) microscopy. We measure the polarity and amplitude of the PC while varying the Fermi level by tuning a gate voltage. These measurements show that the genera...

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Bibliographic Details
Published in:arXiv.org 2009-07
Main Authors: Xu, Xiaodong, Gabor, Nathaniel M, Alden, Jonathan S, Arend van der Zande, McEuen, Paul L
Format: Article
Language:English
Subjects:
Bilayers
Cryogenic temperature
Graphene
Monolayers
Optoelectronics
Photoelectric effect
Photoelectric emission
Polarity
Temperature dependence
Thermal conductivity
Thermoelectricity
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Summary:We investigate the optoelectronic response of a graphene interface junction, formed with bilayer and single-layer graphene, by photocurrent (PC) microscopy. We measure the polarity and amplitude of the PC while varying the Fermi level by tuning a gate voltage. These measurements show that the generation of PC is by a photo-thermoelectric effect. The PC displays a factor of ~10 increase at the cryogenic temperature as compared to room temperature. Assuming the thermoelectric power has a linear dependence on the temperature, the inferred graphene thermal conductivity from temperature dependent measurements has a T^{1.5} dependence below ~100 K, which agrees with recent theoretical predictions.
ISSN:2331-8422
DOI:10.48550/arxiv.0907.3173