Polarization anisotropy of photoluminescence from multilayer InAs/GaAs quantum dots

Humlíček, Josef; Munzar, Dominik; Navrátil, K.; Lorenc, Michal; Oswald, J.; Pangrác, J.; Hulicius, E.

doi:10.1016/s1386-9477(01)00526-4

Cited by 8 publications

(6 citation statements)

References 7 publications

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“…17). The emission radiation from samples S with and S cap is polarized along the [110] crystallographic direction, in agreement with results on type-I InAs/GaAs QDs [109] where the polarization anisotropy of I(θ) is given predominantly by the orientation of the wavefunction of hole states. Based on that, and noting the results of Ref.…”

Section: Polarization Of Emissionsupporting

confidence: 84%

Optical response of (InGa)(AsSb)/GaAs quantum dots embedded in a GaP matrix

et al. 2019

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The optical response of (InGa)(AsSb)/GaAs quantum dots (QDs) grown on GaP (001) substrates is studied by means of excitation and temperature-dependent photoluminescence (PL), and it is related to their complex electronic structure. Such QDs exhibit concurrently direct and indirect transitions, which allows the swapping of Γ and L quantum confined states in energy, depending on details of their stoichiometry. Based on realistic data on QD structure and composition, derived from high-resolution transmission electron microscopy (HRTEM) measurements, simulations by means of k · p theory are performed. The theoretical prediction of both momentum direct and indirect type-I optical transitions are confirmed by the experiments presented here. Additional investigations by a combination of Raman and photoreflectance spectroscopy show modifications of the hydrostatic strain in the QD layer, depending on the sequential addition of QDs and capping layer. A variation of the excitation density across four orders of magnitude reveals a 50 meV energy blueshift of the QD emission. Our findings suggest that the assignment of the type of transition, based solely by the observation of a blueshift with increased pumping, is insufficient. We propose therefore a more consistent approach based on the analysis of the character of the blueshift evolution with optical pumping, which employs a numerical model based on a semi-self-consistent configuration interaction method.

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Section: Polarization Of Emissionsupporting

confidence: 84%

Optical response of (InGa)(AsSb)/GaAs quantum dots embedded in a GaP matrix

et al. 2019

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“…We have recently shown 4 by experimental PL measurements and theoretical calculations that the 9-VSQDs can exhibit TM were independently measured by alonso-Alvarez et al 29 and Humlicek et al 31 , which they were unable to explain. Our multi-million atom simulations 4 assuming circular-base for the QDs qualitatively explained that this anisotropy (DOP [110] = DOP [110] ) is due to a strong confinement of the hole wave functions at the interfaces of QDs (similar to the case of the tall QD of the previous subsection) which tend to align along the [110]direction, and thus significantly reduce the TE [110] -mode.…”

Section: Vertical Stack Of Nine Qds (9-vqds)mentioning

confidence: 91%

“…Vertical stacks of QDs (VSQDs) have shown great potential for tuning of the polarization properties. Recent experiments 6,9,29,31 and theoretical investigations 4,8 have demonstrated that an isotropic polarization response can be realized by geometrical engineering of the VSQDs. In this subsection, we study a vertical stack of closely spaced nine QD layers (9-VSQDs) as shown by the schematic diagram of Fig.…”

Section: Vertical Stack Of Nine Qds (9-vqds)mentioning

confidence: 99%

“…This work, based on multi-million-atom calculations, provides the answer that the interfacial hole wave function confinements have major contribution in the experimentally measured in-plane polarization anisotropy, which is counter-intuitive to the common notion where the shape asymmetry is considered mainly response for such anisotropies. 29,31 Furthermore, as an [110]-elongation increases DOP [110] and reduces DOP [110] , so we investigate the possibility to exploit it to balance the built-in in-plane anisotropy such that to achieve DOP [110] ∼ 0 and DOP [110] ∼ 0? This would lead to the design of the QD based SOAs inde-pendent of the in-plane direction.…”

Section: Introductionmentioning

confidence: 99%

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Atomistic theoretical study of electronic and polarization properties of single and vertically stacked elliptical InAs quantum dots

Usman¹

2012

Phys. Rev. B

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The demonstration of isotropic polarization response from semiconductor quantum dots (QDs) is a crucial step towards the design of several optoelectronic technologies. Among many parameters that impact the degree of polarization (DOP [ − → n ] ) of a QD system, the shape asymmetry is a critical factor. We perform multi-million-atom simulations to study the impact of the elliptical shapes on the electronic and polarization properties of single and vertically stacked InAs QDs. The comparison between a low aspect ratio (AR) and a high AR QD reveals that the electronic and the polarization properties strongly depend on the AR of the QD; the elongation of a tall QD allows tuning of the DOP [ − → n ] over a much wider range. We then extend our analysis to an experimentally reported vertical stack of nine QDs (9-VSQDs) that has shown significant potential to achieve isotropic polarization properties. We analyse the contribution from the shape asymmetry in the experimentally measured large in-plane polarization anisotropy. Our analysis shows that the orientation of the base elongation controls the sign of the DOP [ − → n ] ; however the magnitude of the base elongation has only a very little impact on the magnitude of the DOP [ − → n ] . We further predict that the elliptical shape of the 9-VSQDs can only tune either DOP [110] or DOP [110] for the isotropic response. Our model results, in agreement with the TEM findings, suggest that the experimentally grown 9-VSQDs has either a circular-base or a slightly [110] elongated base. Overall the detailed investigation of the DOP [ − → n ] as a function of the QD shape asymmetry provides a theoretical guidance for the continuing experimental efforts to achieve tailored polarization properties from the QD nano-structures for the design of optical devices.PACS numbers:

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“…The dependence of magnetic fields on the electron transition energy was depressed when the number of vertically coupled layers is increased. To verify the calculated transition energies of the stacked QDs quantitatively, transition energies can be measured experimentally from the photoluminescence spectra [27][28][29][30][31][32]. It is believed that this study is useful for the study of quantum optical structures and design of advanced semiconductor photonic and electronic devices.…”

Section: Discussionmentioning

confidence: 99%

Vertical coupling effects and transition energies in multilayer InAs/GaAs quantum dots

2004

Surface Science

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Polarization anisotropy of photoluminescence from multilayer InAs/GaAs quantum dots

Cited by 8 publications

References 7 publications

Optical response of (InGa)(AsSb)/GaAs quantum dots embedded in a GaP matrix

Optical response of (InGa)(AsSb)/GaAs quantum dots embedded in a GaP matrix

Atomistic theoretical study of electronic and polarization properties of single and vertically stacked elliptical InAs quantum dots

Vertical coupling effects and transition energies in multilayer InAs/GaAs quantum dots

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