Hot carrier relaxation of Dirac fermions in bilayer epitaxial graphene
Artikel i vetenskaplig tidskrift, 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
Författare
[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, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik
[Person 6500575f-452e-4b3e-aa11-cbf26c6725a4 not found]
Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik
[Person 6e16ee3f-a5d0-4165-a25a-c07af11e049c not found]
Chalmers, Mikroteknologi och nanovetenskap (MC2), Kvantkomponentfysik
[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 164202Graphene-Based Revolutions in ICT And Beyond (Graphene Flagship)
Europeiska kommissionen (EU), 2013-10-01 -- 2016-03-31.
Ämneskategorier
Den kondenserade materiens fysik
DOI
10.1088/0953-8984/27/16/164202