Hot carrier transport and photocurrent response in graphene

Nano Lett. 2011 Nov 9;11(11):4688-92. doi: 10.1021/nl202318u. Epub 2011 Sep 30.


Strong electron-electron interactions in graphene are expected to result in multiple-excitation generation by the absorption of a single photon. We show that the impact of carrier multiplication on photocurrent response is enhanced by very inefficient electron cooling, resulting in an abundance of hot carriers. The hot-carrier-mediated energy transport dominates the photoresponse and manifests itself in quantum efficiencies that can exceed unity, as well as in a characteristic dependence of the photocurrent on gate voltages. The pattern of multiple photocurrent sign changes as a function of gate voltage provides a fingerprint of hot-carrier-dominated transport and carrier multiplication.

Publication types

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

MeSH terms

  • Electric Conductivity
  • Graphite / chemistry*
  • Graphite / radiation effects*
  • Light
  • Materials Testing
  • Nanostructures / chemistry*
  • Nanostructures / radiation effects*
  • Radiation Dosage


  • Graphite