Graphene Photocurrent Team's paper published in Science

Congratulations to Nathan, Qiong, Nityan, Thiti and Pablo for their paper, “Hot Carrier–Assisted Intrinsic Photoresponse in Graphene,” being published in Science.

Hot Carrier–Assisted Intrinsic Photoresponse in Graphene
Nathaniel M. Gabor, Justin C. W. Song, Qiong Ma, Nityan L. Nair, Thiti Taychatanapat, Kenji Watanabe, Takashi Taniguchi, Leonid S. Levitov, Pablo Jarillo-Herrero
Science Xpress 6 October 2011: 1211384
We report on the intrinsic optoelectronic response of high-quality dual-gated monolayer and bilayer graphene p-n junction devices. Local laser excitation of wavelength λ = 850 nm at the p-n interface leads to striking six-fold photovoltage patterns as a function of bottom- and top-gate voltages. These patterns, together with the measured spatial and density dependence of the photoresponse, provide strong evidence that nonlocal hot-carrier transport, rather than the photovoltaic effect, dominates the intrinsic photoresponse in graphene. This regime, which features a long-lived and spatially distributed hot carrier population, may open the doorway for hot carrier–assisted thermoelectric technologies for efficient solar energy harvesting.

Press Coverage:
“Electrons heat up in graphene” from Physics World
“Graphene shows unusual thermoelectric response to light” from MIT News