Photo-thermoelectric effect at a graphene interface junction.
We investigate the optoelectronic response of a graphene single-bilayer interface junction using 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 photothermoelectric effect. The PC displays a factor of approximately 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 approximately 100 K, which agrees with recent theoretical predictions.
Xu
Xiaodong
X
Center For Nanoscale Systems, Cornell University,Ithaca, New York 14853, USA.
Gabor
Nathaniel M
NM
Alden
Jonathan S
JS
van der Zande
Arend M
AM
McEuen
Paul L
PL