51. Hot-carrier dynamics in InAs/AlAsSb multiple-quantum wells
- Author
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Herath P. Piyathilaka, Michael B. Santos, Alan D. Bristow, Rishmali Sooriyagoda, Hamidreza Esmaielpour, Tetsuya D. Mishima, Ian R. Sellers, Vincent R. Whiteside, Institut Photovoltaïque d’Ile-de-France (UMR) (IPVF), École polytechnique (X)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-TOTAL FINA ELF-EDF (EDF)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Photovoltaïque d’Ile-de-France (ITE) (IPVF)-Air Liquide [Siège Social], and Esmaielpour, Hamidreza
- Subjects
[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics] ,Photon ,Materials science ,[SPI.OPTI] Engineering Sciences [physics]/Optics / Photonic ,Band gap ,Phonon ,Science ,[SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,Optical spectroscopy ,FOS: Physical sciences ,02 engineering and technology ,Photon energy ,01 natural sciences ,Article ,Metastability ,0103 physical sciences ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing ,010302 applied physics ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,Condensed Matter - Materials Science ,Multidisciplinary ,Scattering ,Materials Science (cond-mat.mtrl-sci) ,021001 nanoscience & nanotechnology ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Density of states ,Medicine ,Atomic physics ,0210 nano-technology ,[SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing ,Excitation - Abstract
A type-II InAs/AlAs$$_{0.16}$$ 0.16 Sb$$_{0.84}$$ 0.84 multiple-quantum well sample is investigated for the photoexcited carrier dynamics as a function of excitation photon energy and lattice temperature. Time-resolved measurements are performed using a near-infrared pump pulse, with photon energies near to and above the band gap, probed with a terahertz probe pulse. The transient terahertz absorption is characterized by a multi-rise, multi-decay function that captures long-lived decay times and a metastable state for an excess-photon energy of $$>100$$ > 100 meV. For sufficient excess-photon energy, excitation of the metastable state is followed by a transition to the long-lived states. Excitation dependence of the long-lived states map onto a nearly-direct band gap ($$E{_g}$$ E g ) density of states with an Urbach tail below $$E{_g}$$ E g . As temperature increases, the long-lived decay times increase $$ < E g , due to the increased phonon interaction of the unintentional defect states, and by phonon stabilization of the hot carriers $$>E{_g}$$ > E g . Additionally, Auger (and/or trap-assisted Auger) scattering above the onset of the plateau may also contribute to longer hot-carrier lifetimes. Meanwhile, the initial decay component shows strong dependence on excitation energy and temperature, reflecting the complicated initial transfer of energy between valence-band and defect states, indicating methods to further prolong hot carriers for technological applications.