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Scott K Cushing - One of the best experts on this subject based on the ideXlab platform.
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hot phonon and carrier relaxation in si 100 determined by transient extreme ultraviolet spectroscopy
Structural Dynamics, 2018Co-Authors: Scott K Cushing, Michael Zurch, Peter M Kraus, Lucas M Carneiro, Angela Lee, Hungtzu Chang, Christopher J Kaplan, Stephen R LeoneAbstract:The thermalization of hot carriers and Phonons gives direct insight into the scattering processes that mediate electrical and thermal transport. Obtaining the scattering rates for both hot carriers and Phonons currently requires multiple measurements with incommensurate timescales. Here, transient extreme-ultraviolet (XUV) spectroscopy on the silicon 2p core level at 100 eV is used to measure hot carrier and phonon thermalization in Si(100) from tens of femtoseconds to 200 ps, following photoexcitation of the indirect transition to the Δ valley at 800 nm. The ground state XUV spectrum is first theoretically predicted using a combination of a single plasmon pole model and the Bethe-Salpeter equation with density functional theory. The excited state spectrum is predicted by incorporating the electronic effects of photo-induced state-filling, broadening, and band-gap renormalization into the ground state XUV spectrum. A time-dependent lattice deformation and expansion is also required to describe the excited state spectrum. The kinetics of these structural components match the kinetics of Phonons excited from the electron-phonon and phonon-phonon scattering processes following photoexcitation. Separating the contributions of electronic and structural effects on the transient XUV spectra allows the carrier population, the population of Phonons involved in inter- and intra-valley electron-phonon scattering, and the population of Phonons involved in phonon-phonon scattering to be quantified as a function of delay time.
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hot phonon and carrier relaxation in si 100 determined by transient extreme ultraviolet spectroscopy
arXiv: Materials Science, 2017Co-Authors: Scott K Cushing, Michael Zurch, Peter M Kraus, Lucas M Carneiro, Angela Lee, Hungtzu Chang, Christopher J Kaplan, Stephen R LeoneAbstract:The thermalization of hot carriers and Phonons gives direct insight into the scattering processes that mediate electrical and thermal transport. Obtaining the scattering rates for both hot carriers and Phonons currently requires multiple measurements with incommensurate timescales. Here, transient extreme-ultraviolet (XUV) spectroscopy on the silicon 2p core level at 100 eV is used to measure hot carrier and phonon thermalization in Si(100) from tens of femtoseconds to 200 ps following photoexcitation of the indirect transition to the {\Delta} valley at 800 nm. The ground state XUV spectrum is first theoretically predicted using a combination of a single plasmon pole model and the Bethe-Salpeter equation (BSE) with density functional theory (DFT). The excited state spectrum is predicted by incorporating the electronic effects of photo-induced state-filling, broadening, and band-gap renormalization into the ground state XUV spectrum. A time-dependent lattice deformation and expansion is also required to describe the excited state spectrum. The kinetics of these structural components match the kinetics of Phonons excited from the electron-phonon and phonon-phonon scattering processes following photoexcitation. Separating the contributions of electronic and structural effects on the transient XUV spectra allows the carrier population, the population of Phonons involved in inter- and intra-valley electron-phonon scattering, and the population of Phonons involved in phonon-phonon scattering to be quantified as a function of delay time.
Stephen R Leone - One of the best experts on this subject based on the ideXlab platform.
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hot phonon and carrier relaxation in si 100 determined by transient extreme ultraviolet spectroscopy
Structural Dynamics, 2018Co-Authors: Scott K Cushing, Michael Zurch, Peter M Kraus, Lucas M Carneiro, Angela Lee, Hungtzu Chang, Christopher J Kaplan, Stephen R LeoneAbstract:The thermalization of hot carriers and Phonons gives direct insight into the scattering processes that mediate electrical and thermal transport. Obtaining the scattering rates for both hot carriers and Phonons currently requires multiple measurements with incommensurate timescales. Here, transient extreme-ultraviolet (XUV) spectroscopy on the silicon 2p core level at 100 eV is used to measure hot carrier and phonon thermalization in Si(100) from tens of femtoseconds to 200 ps, following photoexcitation of the indirect transition to the Δ valley at 800 nm. The ground state XUV spectrum is first theoretically predicted using a combination of a single plasmon pole model and the Bethe-Salpeter equation with density functional theory. The excited state spectrum is predicted by incorporating the electronic effects of photo-induced state-filling, broadening, and band-gap renormalization into the ground state XUV spectrum. A time-dependent lattice deformation and expansion is also required to describe the excited state spectrum. The kinetics of these structural components match the kinetics of Phonons excited from the electron-phonon and phonon-phonon scattering processes following photoexcitation. Separating the contributions of electronic and structural effects on the transient XUV spectra allows the carrier population, the population of Phonons involved in inter- and intra-valley electron-phonon scattering, and the population of Phonons involved in phonon-phonon scattering to be quantified as a function of delay time.
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hot phonon and carrier relaxation in si 100 determined by transient extreme ultraviolet spectroscopy
arXiv: Materials Science, 2017Co-Authors: Scott K Cushing, Michael Zurch, Peter M Kraus, Lucas M Carneiro, Angela Lee, Hungtzu Chang, Christopher J Kaplan, Stephen R LeoneAbstract:The thermalization of hot carriers and Phonons gives direct insight into the scattering processes that mediate electrical and thermal transport. Obtaining the scattering rates for both hot carriers and Phonons currently requires multiple measurements with incommensurate timescales. Here, transient extreme-ultraviolet (XUV) spectroscopy on the silicon 2p core level at 100 eV is used to measure hot carrier and phonon thermalization in Si(100) from tens of femtoseconds to 200 ps following photoexcitation of the indirect transition to the {\Delta} valley at 800 nm. The ground state XUV spectrum is first theoretically predicted using a combination of a single plasmon pole model and the Bethe-Salpeter equation (BSE) with density functional theory (DFT). The excited state spectrum is predicted by incorporating the electronic effects of photo-induced state-filling, broadening, and band-gap renormalization into the ground state XUV spectrum. A time-dependent lattice deformation and expansion is also required to describe the excited state spectrum. The kinetics of these structural components match the kinetics of Phonons excited from the electron-phonon and phonon-phonon scattering processes following photoexcitation. Separating the contributions of electronic and structural effects on the transient XUV spectra allows the carrier population, the population of Phonons involved in inter- and intra-valley electron-phonon scattering, and the population of Phonons involved in phonon-phonon scattering to be quantified as a function of delay time.
Lucas M Carneiro - One of the best experts on this subject based on the ideXlab platform.
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hot phonon and carrier relaxation in si 100 determined by transient extreme ultraviolet spectroscopy
Structural Dynamics, 2018Co-Authors: Scott K Cushing, Michael Zurch, Peter M Kraus, Lucas M Carneiro, Angela Lee, Hungtzu Chang, Christopher J Kaplan, Stephen R LeoneAbstract:The thermalization of hot carriers and Phonons gives direct insight into the scattering processes that mediate electrical and thermal transport. Obtaining the scattering rates for both hot carriers and Phonons currently requires multiple measurements with incommensurate timescales. Here, transient extreme-ultraviolet (XUV) spectroscopy on the silicon 2p core level at 100 eV is used to measure hot carrier and phonon thermalization in Si(100) from tens of femtoseconds to 200 ps, following photoexcitation of the indirect transition to the Δ valley at 800 nm. The ground state XUV spectrum is first theoretically predicted using a combination of a single plasmon pole model and the Bethe-Salpeter equation with density functional theory. The excited state spectrum is predicted by incorporating the electronic effects of photo-induced state-filling, broadening, and band-gap renormalization into the ground state XUV spectrum. A time-dependent lattice deformation and expansion is also required to describe the excited state spectrum. The kinetics of these structural components match the kinetics of Phonons excited from the electron-phonon and phonon-phonon scattering processes following photoexcitation. Separating the contributions of electronic and structural effects on the transient XUV spectra allows the carrier population, the population of Phonons involved in inter- and intra-valley electron-phonon scattering, and the population of Phonons involved in phonon-phonon scattering to be quantified as a function of delay time.
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hot phonon and carrier relaxation in si 100 determined by transient extreme ultraviolet spectroscopy
arXiv: Materials Science, 2017Co-Authors: Scott K Cushing, Michael Zurch, Peter M Kraus, Lucas M Carneiro, Angela Lee, Hungtzu Chang, Christopher J Kaplan, Stephen R LeoneAbstract:The thermalization of hot carriers and Phonons gives direct insight into the scattering processes that mediate electrical and thermal transport. Obtaining the scattering rates for both hot carriers and Phonons currently requires multiple measurements with incommensurate timescales. Here, transient extreme-ultraviolet (XUV) spectroscopy on the silicon 2p core level at 100 eV is used to measure hot carrier and phonon thermalization in Si(100) from tens of femtoseconds to 200 ps following photoexcitation of the indirect transition to the {\Delta} valley at 800 nm. The ground state XUV spectrum is first theoretically predicted using a combination of a single plasmon pole model and the Bethe-Salpeter equation (BSE) with density functional theory (DFT). The excited state spectrum is predicted by incorporating the electronic effects of photo-induced state-filling, broadening, and band-gap renormalization into the ground state XUV spectrum. A time-dependent lattice deformation and expansion is also required to describe the excited state spectrum. The kinetics of these structural components match the kinetics of Phonons excited from the electron-phonon and phonon-phonon scattering processes following photoexcitation. Separating the contributions of electronic and structural effects on the transient XUV spectra allows the carrier population, the population of Phonons involved in inter- and intra-valley electron-phonon scattering, and the population of Phonons involved in phonon-phonon scattering to be quantified as a function of delay time.
Kongthon Tsen - One of the best experts on this subject based on the ideXlab platform.
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studies of electron phonon and phonon phonon interactions in inn using ultrafast raman spectroscopy
Journal of Physics: Condensed Matter, 2009Co-Authors: Kongthon Tsen, D K FerryAbstract:Subpicosecond time-resolved Raman spectroscopy has been employed to investigate electron-phonon interactions and phonon dynamics in InN. The electron-longitudinal optical phonon scattering rate and the decay dynamics of longitudinal optical Phonons in InN have been directly measured. Our results indicate that hot-phonon effects can play an important role in the electron relaxation and transport in InN. The carrier dependence of the lifetime of the longitudinal optical Phonons has also been measured. The results suggest that more theoretical work is needed to account for the dependence of the lifetime of longitudinal optical Phonons on the photoexcited carrier density.
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direct measurements of the lifetimes of longitudinal optical phonon modes and their dynamics in inn
Applied Physics Letters, 2007Co-Authors: Kongthon Tsen, Juliann G Kiang, D K Ferry, Hai Lu, W J SchaffAbstract:Longitudinal optical Phonons in InN have been studied by time-resolved Raman spectroscopy on a subpicosecond time scale. The lifetimes of both the A1(LO) and E1(LO) Phonons have been directly measured. From the temperature dependence of their lifetimes, the authors demonstrate that both Phonons decay primarily into a large wave vector TO phonon and a large wave vector TA/LA phonon, consistent with the accepted phonon dispersion relationship for wurtzite InN.
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time resolved raman studies of the decay of the longitudinal optical Phonons in wurtzite gan
Applied Physics Letters, 1998Co-Authors: Kongthon Tsen, D K Ferry, A Botchkarev, B Sverdlov, A Salvador, H MorkocAbstract:Decay of the longitudinal-optical (LO) Phonons in wurtzite GaN has been studied by subpicosecond time-resolved Raman spectroscopy. Our experimental results show that among the various possible decay channels, the LO Phonons in wurtzite GaN decay primarily into a large wave-vector TO and a large wave-vector LA or TA phonon. These experimental results are consistent with the recent theoretical calculations of the phonon dispersion curves for wurtzite GaN.Decay of the longitudinal-optical (LO) Phonons in wurtzite GaN has been studied by subpicosecond time-resolved Raman spectroscopy. Our experimental results show that among the various possible decay channels, the LO Phonons in wurtzite GaN decay primarily into a large wave-vector TO and a large wave-vector LA or TA phonon. These experimental results are consistent with the recent theoretical calculations of the phonon dispersion curves for wurtzite GaN.
Bernard Perrin - One of the best experts on this subject based on the ideXlab platform.
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strong optical mechanical coupling in a vertical gaas alas microcavity for subterahertz Phonons and near infrared light
Physical Review Letters, 2013Co-Authors: A Fainstein, N D Lanzillottikimura, Bernard Jusserand, Bernard PerrinAbstract:We show that distributed Bragg reflector GaAs/AlAs vertical cavities designed to confine photons are automatically optimal to confine Phonons of the same wavelength, strongly enhancing their interaction. We study the impulsive generation of intense coherent and monochromatic acoustic Phonons by following the time evolution of the elastic strain in picosecond-laser experiments. Efficient optical detection is assured by the strong phonon backaction on the high-Q optical cavity mode. Large optomechanical factors are reported (� THz=nm range). Pillar cavities based in these structures are predicted to display picogram effective masses, almost perfect sound extraction, and threshold powers for the stimulated emission of
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strong optical mechanical coupling in a vertical gaas alas microcavity for subterahertz Phonons and near infrared light
Physical Review Letters, 2013Co-Authors: A Fainstein, N D Lanzillottikimura, Bernard Jusserand, Bernard PerrinAbstract:We show that distributed Bragg reflector GaAs/AlAs vertical cavities designed to confine photons are automatically optimal to confine Phonons of the same wavelength, strongly enhancing their interaction. We study the impulsive generation of intense coherent and monochromatic acoustic Phonons by following the time evolution of the elastic strain in picosecond-laser experiments. Efficient optical detection is assured by the strong phonon backaction on the high-$Q$ optical cavity mode. Large optomechanical factors are reported ($\ensuremath{\sim}\mathrm{THz}/\mathrm{nm}$ range). Pillar cavities based in these structures are predicted to display picogram effective masses, almost perfect sound extraction, and threshold powers for the stimulated emission of Phonons in the range $\ensuremath{\mu}\mathrm{W}--\mathrm{mW}$, opening the way for the demonstration of phonon ``lasing'' by parametric instability in these devices.
