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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Band structure engineering in strain-free GaAs mesoscopic systems

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Author(s):
Gordo, Vanessa Orsi [1] ; Rodrigues, Leonarde N. [2, 3] ; Knopper, Floris [3, 4] ; Garcia Jr, Ailton J. ; Iikawa, Fernando [5] ; Couto Jr, Odilon D. D. ; Deneke, Christoph [6]
Total Authors: 7
Affiliation:
[1] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil
[2] Univ Fed Vicosa, Dept Fis, BR-36570000 Vicosa, MG - Brazil
[3] Lab Nacl Nanotecnol LNNano CNPEM, BR-13083100 Campinas - Brazil
[4] Eindhoven Univ Technol TUe, Dept Appl Phys, Photon & Semicond Nanophys, POB 513, NL-5600 MB Eindhoven - Netherlands
[5] Garcia Jr, Jr., Ailton J., Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil
[6] Couto Jr, Jr., Odilon D. D., Garcia Jr, Jr., Ailton J., Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil
Total Affiliations: 6
Document type: Journal article
Source: Nanotechnology; v. 31, n. 25 APR 3 2020.
Web of Science Citations: 0
Abstract

We investigate the optical properties of strain-free mesoscopic GaAs/AlxGa1 - xAs structures (MGS) coupled to thin GaAs/AlxGa1 - xAs quantum wells (QWs) with varying Al content (x). We demonstrate that quenching the QW emission by controlling the band crossover between AlGaAs (X-point) and GaAs (Gamma-point) gives rise to long carrier lifetimes and enhanced optical emission from the MGS. For x = 0.33, QW and MGS show typical type-I band alignment with strong QW photoluminescence emission and much weaker sharp recombination lines from the MGS localized exciton states. For x >= 0.50, the QW emission is considerably quenched due to the change from type-I to type-II structure while the MGS emission is enhanced due to carrier injection from the QW. For x >= 0.70, we observe PL quenching from the MGS higher energy states also due to the crossover of X and Gamma bands, demonstrating spectral filtering of the MGS emission. Time-resolved measurements reveal two recombination processes in the MGS emission dynamics. The fast component depends mainly on the X - Gamma mixing of the MGS states and can be increased from 0.3 to 2.5 ns by changing the Al content. The slower component, however, depends on the X - Gamma mixing of the QW states and is associated to the carrier injection rate from the QW reservoir into the MGS structure. In this way, the independent tuning of X - Gamma mixing in QW and MGS states allows us to manipulate recombination rates in the MGS as well as to make carrier injection and light extraction more efficient. (AU)

FAPESP's process: 16/16365-6 - Nanostructures of III-V semiconductors and their optical properties
Grantee:Fernando Iikawa
Support type: Regular Research Grants
FAPESP's process: 16/14001-7 - Growth and fabrication of semiconductor nanomembrane structures for basic research and potential device applications
Grantee:Christoph Friedrich Deneke
Support type: Regular Research Grants
FAPESP's process: 12/11382-9 - Optical modulation of semiconductor nanostructures using surface acoustic waves
Grantee:Odilon Divino Damasceno Couto Júnior
Support type: Research Grants - Young Investigators Grants