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Article

Intersubband Transition Engineering in the Conduction Band of Asymmetric Coupled Ge/SiGe Quantum Wells

1
Department of Sciences, Università Roma Tre, Viale G. Marconi 446, I-00146 Rome, Italy
2
Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro, I-00185 Rome, Italy
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IHP-Leibniz-Institut für innovative Mikroelektronik, Im Technologiepark 25, D-15236 Frankfurt (Oder), Germany
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Department of Engineering Physics, École Polytechnique de Montréal, C. P. 6079, Succ. Centre-Ville, Montréal, QC H3C 3A7, Canada
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Department of Physics “Enrico Fermi”, Università di Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy
*
Author to whom correspondence should be addressed.
Crystals 2020, 10(3), 179; https://doi.org/10.3390/cryst10030179
Received: 1 February 2020 / Revised: 3 March 2020 / Accepted: 4 March 2020 / Published: 6 March 2020
(This article belongs to the Special Issue Semiconductor Heteroepitaxy)
n-type Ge/SiGe asymmetric coupled quantum wells represent the building block of a variety of nanoscale quantum devices, including recently proposed designs for a silicon-based THz quantum cascade laser. In this paper, we combine structural and spectroscopic experiments on 20-module superstructures, each featuring two Ge wells coupled through a Ge-rich SiGe tunnel barrier, as a function of the geometry parameters of the design and the P dopant concentration. Through a comparison of THz spectroscopic data with numerical calculations of intersubband optical absorption resonances, we demonstrated that it is possible to tune, by design, the energy and the spatial overlap of quantum confined subbands in the conduction band of the heterostructures. The high structural/interface quality of the samples and the control achieved on subband hybridization are promising starting points towards a working electrically pumped light-emitting device. View Full-Text
Keywords: quantum wells; group IV epitaxy; intersubband transitions; silicon–germanium heterostructures; THz spectroscopy quantum wells; group IV epitaxy; intersubband transitions; silicon–germanium heterostructures; THz spectroscopy
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MDPI and ACS Style

Persichetti, L.; Montanari, M.; Ciano, C.; Di Gaspare, L.; Ortolani, M.; Baldassarre, L.; Zoellner, M.; Mukherjee, S.; Moutanabbir, O.; Capellini, G.; Virgilio, M.; De Seta, M. Intersubband Transition Engineering in the Conduction Band of Asymmetric Coupled Ge/SiGe Quantum Wells. Crystals 2020, 10, 179. https://doi.org/10.3390/cryst10030179

AMA Style

Persichetti L, Montanari M, Ciano C, Di Gaspare L, Ortolani M, Baldassarre L, Zoellner M, Mukherjee S, Moutanabbir O, Capellini G, Virgilio M, De Seta M. Intersubband Transition Engineering in the Conduction Band of Asymmetric Coupled Ge/SiGe Quantum Wells. Crystals. 2020; 10(3):179. https://doi.org/10.3390/cryst10030179

Chicago/Turabian Style

Persichetti, Luca, Michele Montanari, Chiara Ciano, Luciana Di Gaspare, Michele Ortolani, Leonetta Baldassarre, Marvin Zoellner, Samik Mukherjee, Oussama Moutanabbir, Giovanni Capellini, Michele Virgilio, and Monica De Seta. 2020. "Intersubband Transition Engineering in the Conduction Band of Asymmetric Coupled Ge/SiGe Quantum Wells" Crystals 10, no. 3: 179. https://doi.org/10.3390/cryst10030179

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