Temporal characterization of hot-electron thermoelectric effect in monolayer graphene devices
Published/Posted: March 1, 2013
Authors: Suess, R. J.; Cai, X.; Sushkov, A.; Jenkins, G.; Kim, M.-H.; Yan, J.; Drew, H. D.; Murphy, T. E.; Fuhrer, M. S.Abstract: Graphene's unique electronic and optical properties have made it an attractive candidate material for photonics applications such as broadband optical detection. We report the temporal response of a monolayer graphene device with dissimilar metal electrodes in which optically induced hot-electrons are detected via a thermoelectric voltage induced between the electrodes. Measurements are carried out with a pulsed laser system (60 fs pulse width) at the telecom wavelength of 1.5 μm using an asynchronous optical sampling pulse coincidence technique. Graphene's weak electron-phonon coupling and our compact device geometry (comparable to the thermal diffusion length) result in a fast 10 - 20 ps non-linear thermal response that is nearly independent of temperature over the measured range of 15 - 150 K. Sensitivity of the devices response to optical power will also be discussed. These results are a follow-on to other talks reported by our group at this conference in which the fabrication, operating principal, and broad wavelength (THz to near IR) response of the graphene-based hot-electron bolometer are described.
R. J. Suess, X. Cai, A. Sushkov, G. Jenkins, M.-H. Kim, J. Yan, H. D. Drew, T. E. Murphy and M. S. Fuhrer, "Temporal characterization of hot-electron thermoelectric effect in monolayer graphene devices", APS March Meeting, Baltimore, MD (USA) BAPS.2013.MAR.J7.7 (2013)