The optical properties of strain-coupled InAs/GaAs quantum-dot heterostructures with varying thicknesses of GaAs and InGaAs spacer layers

Shetty, Saikalash; Adhikary, Sourav; Tongbram, Binita; Ahmad, Aijaz; Ghadi, Hemant; Chakrabarti, Subhananda

doi:10.1016/j.jlumin.2014.10.013

Cited by 22 publications

(2 citation statements)

References 30 publications

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“…Zhou investigated the influences of lattice mismatches on equilibrium morphologies and strain distributions of quantum dots [21]. The effect of strain and stress on the properties of QDs have been reported in literatures as well [22][23][24][25][26]. Different shapes such as pyramidal, conical, lens-shaped and truncated pyramid of InAs QDs are found by scanning tunneling microscope (STM) or atomic force microscope (AFM) researches.…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of stress and strain distribution in coupled pyramidal InAs quantum dots embedded in GaAs by finite element method

et al. 2019

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Stress and strain distributions in and around a single or two-coupled pyramidal InAs quantum dots (QDs) embedded in GaAs are calculated by finite element methods according to the continuum elasticity theory. By changing the quantum dot spacing and thickness of cap layer, the results about strain and stress distributions show compressive strain and stress distribution in the QDs and relaxation undergoes two stages with different speeds for different quantum dot height, quantum width and thickness of cap layer. The stress and strain distributions of pyramidal QDs would not vary monotonously with geometric dimensions. The height of quantum dot and cap layer thickness can effectively adjust the vertical correlation of self-assembly QDs according to the calculation. The shape of stress distribution at surface of cap layer can be tuned from a quadrangle into a circle by increasing the thickness of cap layer or decreasing the height of quantum dot. Also, a new approach to grow quantum ring is found in this paper. The calculations of two-coupled QDs show that the self-assembly technology might fail if the horizontal distance between two QDs is not large enough. The stress induced by upper QDs will be relaxed to zero with a longer distance downwards is found in this paper.

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Section: Introductionmentioning

confidence: 99%

Theoretical study of stress and strain distribution in coupled pyramidal InAs quantum dots embedded in GaAs by finite element method

et al. 2019

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“…The optical properties of InAs/GaAs QDs have been investigated via photoluminescence (PL) and photoluminescence excited (PLE) techniques [20][21][22], but the information obtained is often limited to only the lower energy states, which does not allow a deduction of the shape of QD potential. However, other methods, such as electroreflectance (ER) [23][24][25], reflectance-difference [26] and photoreflectance (PR) [16,[23][24][27][28] techniques can detect higher energy transitions in the QD and other layers.…”

Section: Introductionmentioning

confidence: 99%

Photoreflectance study of the GaAs buffer layer in InAs/GaAs quantum dots

Trujillo

Barragán

Calderón

et al. 2017

Superficies y Vacio

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GaAs buffer layer in InAs/GaAs quantum dots (QDs) was investigated by Photoreflectance (PR) technique at 300 K. PR spectra obtained were compared with commercial GaAs sample PR spectra, and they were analyzed by using the derivative Lorentzian functions as proposed by Aspnes in the middle field regimen. PR spectra in InAs/GaAs QDs sample was attributed to the photoreflectance response in the GaAs buffer layer. Band bending energies were calculated for laser intensities from 1 mW to 21 mW. The photoreflectance comparative study in the samples was realized considering the difference in the parameters: electric field on the surface, broadening parameter, energy gained by photoexcited carriers due to the electric field applied, frequency of light and heavy holes and band bending energy values. The results suggest that the presence of InAs quantum dots increases the light and heavy holes frequencies and the band bending energy values; and decreases the electric field on the surface, the broadening parameter and the energy gained by photoexcited carriers. We found that InAs QDs presence modifies the surface electrical field around one order of magnitude in the GaAs buffer layer and this behavior can be attributed to surface passivation.

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In0.5Ga0.5As Bilayer Quantum Dot Heterostructure for mid-infrared photodetection

Panda

Balgarkashi

Singh

et al. 2018

Infrared Physics & Technology

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The optical properties of strain-coupled InAs/GaAs quantum-dot heterostructures with varying thicknesses of GaAs and InGaAs spacer layers

Cited by 22 publications

References 30 publications

Theoretical study of stress and strain distribution in coupled pyramidal InAs quantum dots embedded in GaAs by finite element method

Theoretical study of stress and strain distribution in coupled pyramidal InAs quantum dots embedded in GaAs by finite element method

Photoreflectance study of the GaAs buffer layer in InAs/GaAs quantum dots

In0.5Ga0.5As Bilayer Quantum Dot Heterostructure for mid-infrared photodetection

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