Emission of InAs quantum dots embedded in InGaAs/InAlGaAs/GaAs quantum wells
Autor: | I.J. Guerrero Moreno, R. Cisneros Tamayo, Georgiy Polupan, Tetyana Torchynska, J. Palacios Gomez |
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Rok vydání: | 2014 |
Předmět: |
Diffraction
Photoluminescence Materials science Band gap business.industry Biophysics General Chemistry Atmospheric temperature range Condensed Matter Physics Laser Biochemistry Atomic and Molecular Physics and Optics law.invention law Quantum dot X-ray crystallography Optoelectronics business Quantum well |
Zdroj: | Journal of Luminescence. 149:1-6 |
ISSN: | 0022-2313 |
Popis: | Photoluminescence (PL), its temperature dependences and X-ray diffraction (XRD) have been investigated in MBE grown GaAs/Al 0.3 Ga 0.7 As/In 0.15 Ga 0.85 As/InAlGaAs/GaAs quantum wells (QWs) with embedded InAs quantum dots (QDs). Studied QD structures are the important part of low-threshold, high-power lasers for optical fiber communication systems. Three types of QD structures with different capping layers (GaAs, Al 0.3 Ga 0.7 As and Al 0.1 Ga 0.75 In 0.15 As) were investigated. The comparison of the impact of capping layer compositions on PL parameters of InAs QDs and the process of Ga/Al/In intermixing has been obtained. QD emission is analyzed in the temperature range of 10–500 K and the QD emission shift has been compared with the temperature shrinkage of band gaps in the bulk InAs and GaAs crystals. Different changes of QD compositions owing to Ga/Al/In intermixing have been revealed in studied structures. The XRD study is used to control a composition of QW layers and to confirm additionally that the efficiency of Ga/Al/In intermixing depends on capping layer types. The thermal decay of integrated PL intensities has been investigated as well. The PL thermal decay 557-fold in the range 10–300 K is revealed in the structure with GaAs capping layer in comparison with the 6- and 20-fold PL decays in structures with Al 0.3 Ga 0.7 As and Al 0.1 Ga 0.75 In 0.15 As capping layers, respectively. The reason of PL spectrum transformation and the mechanism of PL thermal decay in QD structures with different capping layer compositions have been analyzed and discussed. |
Databáze: | OpenAIRE |
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