Hot carrier relaxation of Dirac fermions in bilayer epitaxial graphene
Journal article, 2015

Energy relaxation of hot Dirac fermions in bilayer epitaxial graphene is experimentally investigated by magnetotransport measurements on Shubnikov-de Haas oscillations and weak localization. The hot-electron energy loss rate is found to follow the predicted Bloch-Gruneisen power-law behaviour of T-4 at carrier temperatures from 1.4K up to similar to 100 K, due to electron-acoustic phonon interactions with a deformation potential coupling constant of 22 eV. A carrier density dependence n(e)(-1.5) in the scaling of the T-4 power law is observed in bilayer graphene, in contrast to the n(e)(-0.5) dependence in monolayer graphene, leading to a crossover in the energy loss rate as a function of carrier density between these two systems. The electron-phonon relaxation time in bilayer graphene is also shown to be strongly carrier density dependent, while it remains constant for a wide range of carrier densities in monolayer graphene. Our results and comparisons between the bilayer and monolayer exhibit a more comprehensive picture of hot carrier dynamics in graphene systems.

hot carriers

magnetotransport

energy loss rate

bilayer graphene

Author

[Person 70afc231-891e-44a3-945b-7738ffa004e1 not found]

University of Oxford

[Person 7fcf1f77-f671-4f59-a03d-dc2b8cd29509 not found]

University of Oxford

[Person c5fbbbe2-5607-45f1-8fbd-0227698477f2 not found]

National Physical Laboratory (NPL)

[Person 6eead786-3acf-4000-8be5-aa0dfc3dbedd not found]

National Physical Laboratory (NPL)

Royal Holloway University of London

[Person 14cf7bf0-5560-45f6-b4ab-78d3908f4c5e not found]

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

[Person 6500575f-452e-4b3e-aa11-cbf26c6725a4 not found]

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

[Person 6e16ee3f-a5d0-4165-a25a-c07af11e049c not found]

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

[Person ecb6b0e6-5fdc-431c-a6d1-3d8b70730fb9 not found]

Naval Research Laboratory

[Person 51e6c5c7-d211-47e7-830e-48b69ac59d93 not found]

Naval Research Laboratory

[Person be1d4b4d-e0e9-46a7-9be5-593fd72b2d61 not found]

Naval Research Laboratory

[Person e3b6ba66-7c97-4ff4-9854-426eda52a131 not found]

University of Oxford

Journal of Physics Condensed Matter

0953-8984 (ISSN)

Vol. 27 16 164202

Graphene-Based Revolutions in ICT And Beyond (Graphene Flagship)

European Commission (EC), 2013-10-01 -- 2016-03-31.

Subject Categories

Condensed Matter Physics

DOI

10.1088/0953-8984/27/16/164202

More information

Latest update

5/29/2018