Photoluminescence and In/Ga Intermixture in InAs/InGaAs DWELL Structures

2009 ◽  
Vol 1242 ◽  
Author(s):  
A. Vivas Hernandez ◽  
I.J. Guerrero Moreno ◽  
E. Velázquez Lozada
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Ground State ◽  
Elastic Stress ◽  
Blue Shift ◽  
Inas Quantum Dots ◽  
Temperature Dependences ◽  
Different Temperatures ◽  
Fitting Parameters ◽  
Varshni Relation

ABSTRACTThe photoluminescence (PL) and photoluminescence temperature dependences have been studied in InAs quantum dots (QDs) embedded in the In0.15Ga1–0.15As/GaAs quantum wells (QWs) with QDs grown at different temperatures (470–535 °C). Ground state (GS) related QD PL peaks shift into the red side with increasing QD growth temperature to 510 °C and the blue shift is observed when the temperature increased to 535 °C. The temperature dependences of GS PL peak positions were fitted on the base of Varshni relation and the fitting parameters were compared with the bulk InAs and the In0.21Ga0.79As allow. This comparison has revealed that for QDs grown at 490–510 °C the PL fitting parameters are the same as for the bulk InAs crystal. The DWELL structures with QDs grown at other temperatures have fitting parameters different from the bulk InAs. Last fact testifies that in these structures the Ga/In inter-diffusion between QDs and a QW has been realized. This Ga/In intermixture can be stimulated not only by the high temperature (535 °C), but by the essential elastic stress as well in the DWELL structure with lower QD densities.

Emission and X ray diffraction in AlGaAs/ InGaAs Quantum wells with embedded InAs Quantum dots

2013 ◽  
Vol 1617 ◽  
pp. 43-48
Author(s):  
R. Cisneros Tamayo ◽  
I.J. Gerrero Moreno ◽  
A. Vivas Hernandez ◽  
J.L. Casas Espinola ◽  
L. Shcherbyna
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Thermal Annealing ◽  
Peak Position ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Prepared State ◽  
Temperature Dependences

ABSTRACTThe photoluminescence (PL), its temperature dependence and X-ray diffraction (XRD) have been studied in MBE grown GaAs/AlGaAs/InGaAs/AlGaAs /GaAs quantum wells (QWs) with InAs quantum dots embedded in the center of InGaAs layer in the freshly prepared states and after the thermal treatments during 2 hours at 640 or 710 °C. The structures contained two buffer (Al0.3Ga0.7As/In0.15Ga0.85As) and two capping (In0.15Ga0.85As / Al0.3Ga0.7As) layers. The temperature dependences of PL peak positions have been analyzed in the temperature range 10-500K with the aim to investigate the QD composition and its variation at thermal annealing. The experimental parameters of the temperature variation of PL peak position in the InAs QDs have been compared with the known one for the bulk InAs crystals and the QD composition variation due to Ga/Al/In inter diffusion at thermal treatments has been detected. XRD have been studied with the aim to estimate the capping/buffer layer compositions in the different QW layers in freshly prepared state and after the thermal annealing. The obtained emission and XRD data and their dependences on the thermal treatment have been analyzed and discussed.

Emission and strain in InGaAs/GaAs quantum wells with InAs quantum dots obtained at different temperatures

2012 ◽  
Vol 52 (4) ◽  
pp. 844-850
Author(s):  
R.L. Mascorro Alquicira ◽  
J.L. Casas Espinola ◽  
E. Velázquez Lozada ◽  
G. Polupan ◽  
L. Shcherbyna
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Inas Quantum Dots ◽  
Different Temperatures

Modeling of the effect of bio-conjugation to anti-interleukin-10 antibodieson the photoluminescence of CdSe/ZnS quantum dots

2013 ◽  
Vol 1617 ◽  
pp. 145-150
Author(s):  
Tetyana V. Torchynska ◽  
Yuri V. Vorobiev ◽  
Paul P. Horley
Keyword(s):  
Quantum Dots ◽  
Ground State ◽  
Targeted Drug Delivery ◽  
Blue Shift ◽  
Interleukin 10 ◽  
Theoretical Description ◽  
Luminescence Spectra ◽  
Scientific Interest ◽  
Targeted Drug ◽  
Nano Medicine

ABSTRACTBio-conjugated CdSe/ZnS core/shell quantum dots (QDs) attract essential scientific interest due to their possible nano-medicine applications, including selective highlighting of affected tissues and targeted drug delivery to the certain type of cells. The paper is focused on the theoretical description of the blue shift observed in the luminescence spectra of CdSe/ZnS QDs upon their bio-conjugation with the anti-interleukin-10 antibodies. We propose a model that describes the ground state of the exciton confined in a quantum dot and explaining the bio-conjugation phenomenon by the change of the effective confinement volume.

Mid-Infrared Photodetector Using Self-Assembled InAs Quantum Dots Embedded in Modulation-Doped GaAs Quantum Wells

1999 ◽  
Vol 607 ◽  
Author(s):  
Seung-Woong Lee ◽  
Kazuhiko Hirakawa ◽  
Yozo Shimada
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
High Mobility ◽  
Normal Incidence ◽  
Infrared Photodetector ◽  
Inas Quantum Dots ◽  
Operation Temperature ◽  
Long Lifetime ◽  
Quantum Dot Infrared Photodetector ◽  
Self Assembled

AbstractWe have designed and fabricated a quantum dot infrared photodetector which utilizes lateral transport of photoexcited carriers in the modulation-doped A1GaAs/GaAs two-dimensional (2D) channels. A broad photocurrent signal has been observed in the photon energy range of 100–300 meV due to bound-to-continuum intersubband absorption of normal incidence radiation in the self-assembled InAs quantum dots. A peak responsivity was as high as 2.3 A/W. The high responsivity is realized mainly by a high mobility and a long lifetime of photoexcited carriers in the modulation-doped 2D channels. Furthermore, we found that this device has high operation temperature and very high photoconductive gain.

Emission of InAs quantum dots embedded in InGaAs/InAlGaAs/GaAs quantum wells

2014 ◽  
Vol 149 ◽  
pp. 1-6 ◽  
Author(s):  
R. Cisneros Tamayo ◽  
I.J. Guerrero Moreno ◽  
G. Polupan ◽  
T.V. Torchynska ◽  
J. Palacios Gomez
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Inas Quantum Dots

Photoluminescence of InAs quantum dots embedded in AlGaAs/InGaAs quantum wells with strain reducing layer

2014 ◽  
Vol 71 ◽  
pp. 168-176 ◽  
Author(s):  
R. Cisneros Tamayo ◽  
T.V. Torchynska ◽  
G. Polupan ◽  
I.J. Guerrero Moreno ◽  
E. Velázquez Lozada ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Wells ◽  
Inas Quantum Dots
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