Optical studies of an exciton and a biexciton in a CdTe/ZnTe quantum dot nanostructure

Sujanah, P.; Peter, A. John; Lee, Chang Woo

doi:10.1016/j.optcom.2014.09.061

Cited by 8 publications

(3 citation statements)

References 34 publications

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“…The behavior of the binding energies without pressure (P ¼ 0 kbar) is similar to the previous results found in refs. [38,39,49,50]. For all pressures, we observe that the binding energy increases from its bulk value in GaAs as the dot radius is reduced, reaches a maximum value, and then drops to the bulk value characteristic of the barrier material as the dot radius goes to zero.…”

Section: Resultsmentioning

confidence: 75%

Hydrostatic Pressure Dependent Optoelectronic Properties of InGaAsN/GaAs Spherical Quantum Dots for Laser Diode Applications

Mal

Jayarubi²,

Das³

et al. 2018

Physica Status Solidi (b)

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The hydrostatic pressure induced band diagram of an InGaAsN/GaAs spherical quantum dot (QD) system is theoretically calculated using an expanded form of standard 8 band k · p Hamiltonian. The band parameters including energy gap, band offsets, and effective masses of electron and hole as a function of hydrostatic pressure are extracted using 10 band k · p model to calculate optical gain, threshold current density, and confined exciton binding energies of the QD system for the possible potential applications in 1.3–1.55 μm laser diodes. The optical gain increases with the increase in hydrostatic pressure up to 30 kbar and eventually decreases for further application of higher pressures. This effect is not usually observed in InGaAsN/GaAs quantum wells owing to the strong dependence of hole and electron effective masses with the hydrostatic pressure. A relative blue shift is observed in the gain spectra due to the increase in hydrostatic pressure or carrier concentration whereas a redshift is observed due to the increase in geometrical dimensions or impurity concentration which helps in estimating the range of operation of InGaAsN/GaAs QD based devices. The obtained binding energies, threshold current densities, and strain within the QDs help in understanding the influence of pressure and dot radius on these parameters.

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Section: Resultsmentioning

confidence: 75%

Hydrostatic Pressure Dependent Optoelectronic Properties of InGaAsN/GaAs Spherical Quantum Dots for Laser Diode Applications

Mal

Jayarubi²,

Das³

et al. 2018

Physica Status Solidi (b)

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show abstract

“…6). In the case of CdSe or CdTe based QDs the ∆E X−XX exhibits typically a low scatter and remains in a relatively narrow range of 20-25 meV [38][39][40]43,[45][46][47][48] or 12-15 meV [44][45][46]49,50 , respectively. Hence, the ∆E X−XX in our case spans from values typical for the CdSe/ZnSe QDs, through values typical for the CdTe/ZnTe QDs, down to much lower values, which were not observed before for the CdSe or the CdTe based QDs systems and which would not be expected for the Cd(Se,Te)/ZnSe QDs if they were homogeneous in a volume.…”

Section: Discussionmentioning

confidence: 99%

“…Note that the QD1 exhibits much lower intensity as compared to the QD2, as expected for a QD with a decreased exciton oscillator strength resulting from a decreased e-h overlap. 42,44 The spectra of the XX and X transitions from the QD1 and the QD2 plotted as a function of a detected linear polarization angle reveal two linearly polarized orthogonal components (see panels c-f) in the Fig. 5).…”

Section: B Impact Of E-h Wavefunctions Overlap On Landé Factor and An...mentioning

confidence: 96%

Effect of electron-hole separation on optical properties of individual Cd(Se,Te) quantum dots

et al. 2016

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Cd(Se,Te) Quantum Dots (QD) in ZnSe barrier typically exhibit a very high spectral density, which precludes investigation of single dot photoluminescence. We design, grow and study individual Cd(Se,Te)/ZnSe QDs of low spectral density of emission lines achieved by implementation of a Mnassisted epitaxial growth. We find an unusually large variation of exciton-biexciton energy difference (3 meV ≤ ∆EX−XX ≤ 26 meV) and of exciton radiative recombination rate in the statistics of QDs. We observe a strong correlation between the exciton-biexciton energy difference, exciton recombination rate, splitting between dark and bright exciton, and additionally the exciton fine structure splitting δ1 and Landé factor. Above results indicate that values of the δ1 and of the Landé factor in the studied QDs are dictated primarily by the electron and hole respective spatial shift and wavefunctions overlap, which vary from dot to dot due to a different degree of localization of electrons and holes in, respectively, CdSe and CdTe rich QD regions.

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Binding energy and the third-order nonlinear optical susceptibility of an exciton in GaAs/AlGaAs core/shell spherical quantum dot

Zhang

Guo

et al. 2018

J Opt

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Optical studies of an exciton and a biexciton in a CdTe/ZnTe quantum dot nanostructure

Cited by 8 publications

References 34 publications

Hydrostatic Pressure Dependent Optoelectronic Properties of InGaAsN/GaAs Spherical Quantum Dots for Laser Diode Applications

Hydrostatic Pressure Dependent Optoelectronic Properties of InGaAsN/GaAs Spherical Quantum Dots for Laser Diode Applications

Effect of electron-hole separation on optical properties of individual Cd(Se,Te) quantum dots

Binding energy and the third-order nonlinear optical susceptibility of an exciton in GaAs/AlGaAs core/shell spherical quantum dot

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