TY - JOUR
T1 - Influence of carrier density on the electronic cooling channels of bilayer graphene
AU - Limmer, T.
AU - Houtepen, A. J.
AU - Niggebaum, A.
AU - Tautz, R.
AU - Da Como, E.
PY - 2011/9
Y1 - 2011/9
N2 - We study the electronic cooling dynamics in a single flake of bilayer graphene by femtosecond transient absorption probing the photon-energy range 0.25–1.3 eV. From the transients, we extract the carrier cooling curves for different initial temperatures and densities of the photoexcited electrons and holes. Two regimes of carrier cooling, dominated by optical and acoustic phonons emission, are clearly identified. For increasing carrier density, the crossover between the two regimes occurs at larger carrier temperatures, since cooling via optical phonons experiences a bottleneck. Acoustic phonons, which are less sensitive to saturation, show an increasing contribution at high density.
AB - We study the electronic cooling dynamics in a single flake of bilayer graphene by femtosecond transient absorption probing the photon-energy range 0.25–1.3 eV. From the transients, we extract the carrier cooling curves for different initial temperatures and densities of the photoexcited electrons and holes. Two regimes of carrier cooling, dominated by optical and acoustic phonons emission, are clearly identified. For increasing carrier density, the crossover between the two regimes occurs at larger carrier temperatures, since cooling via optical phonons experiences a bottleneck. Acoustic phonons, which are less sensitive to saturation, show an increasing contribution at high density.
UR - http://www.scopus.com/inward/record.url?scp=80052820271&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1063/1.3633099
U2 - 10.1063/1.3633099
DO - 10.1063/1.3633099
M3 - Article
SN - 0003-6951
VL - 99
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 10
M1 - 103104
ER -