Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution
Ultra-fast optical measurements of few-layer suspended graphene films grown by chemical vapor deposition were performed with femtosecond pump–probe spectroscopy. The relaxation processes were monitored in transient differential transmission (ΔT/T) after excitation at two different wavelengths of 350...
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sg-ntu-dr.10356-959342020-03-07T12:37:22Z Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution Gurzadyan, Gagik G. Shang, Jingzhi Yu, Ting School of Physical and Mathematical Sciences Ultra-fast optical measurements of few-layer suspended graphene films grown by chemical vapor deposition were performed with femtosecond pump–probe spectroscopy. The relaxation processes were monitored in transient differential transmission (ΔT/T) after excitation at two different wavelengths of 350 and 680 nm. Intraband electron–electron scattering, electron–phonon scattering, interband Auger recombination and impact ionization were considered to contribute to ΔT/T. All these processes may play important roles in spreading the quasiparticle distribution in time scales up to 100 fs. Optical phonon emission and absorption by highly excited non-equilibrium electrons were identified from ΔT/T peaks in the wide spectral range. When the probe energy region was far from the pump energy, the energy dependence of the quasiparticle decay rate was found to be linear. Longer lifetimes were observed when the quasiparticle population was localized due to optical phonon emission or absorption. 2013-06-27T02:27:35Z 2019-12-06T19:23:29Z 2013-06-27T02:27:35Z 2019-12-06T19:23:29Z 2011 2011 Journal Article Shang, J., Yu, T., & Gurzadyan, G. G. (2012). Femtosecond energy relaxation in suspended graphene: phonon-assisted spreading of quasiparticle distribution. Applied Physics B, 107(1), 131-136. 0946-2171 https://hdl.handle.net/10356/95934 http://hdl.handle.net/10220/10763 10.1007/s00340-011-4853-0 en Applied physics B © 2011 Springer-Verlag. |
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Ultra-fast optical measurements of few-layer suspended graphene films grown by chemical vapor deposition were performed with femtosecond pump–probe spectroscopy. The relaxation processes were monitored in transient differential transmission (ΔT/T) after excitation at two different wavelengths of 350 and 680 nm. Intraband electron–electron scattering, electron–phonon scattering, interband Auger recombination and impact ionization were considered to contribute to ΔT/T. All these processes may play important roles in spreading the quasiparticle distribution in time scales up to 100 fs. Optical phonon emission and absorption by highly excited non-equilibrium electrons were identified from ΔT/T peaks in the wide spectral range. When the probe energy region was far from the pump energy, the energy dependence of the quasiparticle decay rate was found to be linear. Longer lifetimes were observed when the quasiparticle population was localized due to optical phonon emission or absorption. |
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School of Physical and Mathematical Sciences |
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School of Physical and Mathematical Sciences Gurzadyan, Gagik G. Shang, Jingzhi Yu, Ting |
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Gurzadyan, Gagik G. Shang, Jingzhi Yu, Ting |
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Gurzadyan, Gagik G. Shang, Jingzhi Yu, Ting Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution |
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Gurzadyan, Gagik G. |
title |
Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution |
title_short |
Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution |
title_full |
Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution |
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Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution |
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Femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution |
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femtosecond energy relaxation in suspended graphene : phonon-assisted spreading of quasiparticle distribution |
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2013 |
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https://hdl.handle.net/10356/95934 http://hdl.handle.net/10220/10763 |
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