Pulsed Near-IR Photoresponse in a Bi-metal Contacted Graphene Photodetector

Xinghan Cai; Ryan J Suess; H Dennis Drew; Thomas E Murphy; Jun Yan; Michael S Fuhrer

doi:10.1038/srep14803

Pulsed Near-IR Photoresponse in a Bi-metal Contacted Graphene Photodetector

Sci Rep. 2015 Oct 6:5:14803. doi: 10.1038/srep14803.

Authors

Xinghan Cai¹, Ryan J Suess², H Dennis Drew¹, Thomas E Murphy², Jun Yan³, Michael S Fuhrer^{1

4}

Affiliations

¹ Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742-4111 USA.
² Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742 USA.
³ Department of Physics, University of Massachusetts, Amherst, MA 01003, USA.
⁴ School of Physics, Monash University, 3800 Victoria, Australia.

Abstract

We use an ultra-fast near-infrared pulse coincidence technique to study the time, temperature, and power dependence of the photoresponse of a bi-metal contacted graphene photodetector. We observe two components of the photovoltage signal. One component is gate-voltage dependent, linear in power at room temperature and sub-linear at low temperature-consistent with the hot-electron photothermoelectric effect due to absorption in the graphene. The power dependence is consistent with supercollision-dominated cooling in graphene. The other component is gate-voltage independent and linear in temperature and power, which we interpret as due to thermoelectricity of the metal electrodes due to differential light absorption.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.