Wire-like characteristics in stacked InAs/GaAs quantum dot superlattices for optoelectronic devices

Chen, T T; Chen, Y F; Wang, J S; Huang, Ying; Hsiao, R. S.; Chen, J F; Lai, Chih‐Ming; Y, J

doi:10.1088/0268-1242/22/9/017

Cited by 5 publications

(1 citation statement)

References 15 publications

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“…The effect of vertical coupling of the bandgap of the active region is studied in [14] where it has been shown that the surface photovoltaic signal can be enhanced by up to more than 100 times due to vertical coupling. To the best of our knowledge there is no work in the literature that studies the vertical coupling effects between multiple stacks of QD layers in a semiconductor optical amplifier.…”

Section: Introductionmentioning

confidence: 99%

Vertical coupling in multiple stacks quantum-dot semiconductor optical amplifiers

Qasaimeh¹

2009

J. Phys. D: Appl. Phys.

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The characteristics of vertically coupled multiple stacks quantum-dot (QD) semiconductor optical amplifiers (SOAs) are studied taking into account the effect of carrier coupling between adjacent stacks. We find that QD-SOAs that consist of a few numbers of stacks provide higher optical gain at lower applied current. Our analysis shows that the optical gain of the amplifier can be considerably enhanced due to short tunnelling lifetimes between adjacent stacks. Also, our analysis reveals that short coupling lifetimes can significantly reduce the transparency current and improve the uniformity of the active region since the net coupling rate is a linear function of the injection rate. Long coupling lifetime, on the other hand, produces non-linear and non-uniform coupling rates, which reduce the optical gain and increase the transparency current of the amplifier. We also find that the degradation in the unsaturated optical gain due to long coupling lifetimes is more severe in p-type doped QD-SOA compared with un-doped QD-SOA.

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Section: Introductionmentioning

confidence: 99%

Vertical coupling in multiple stacks quantum-dot semiconductor optical amplifiers

Qasaimeh¹

2009

J. Phys. D: Appl. Phys.

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Effect of dimensionality and morphology on polarized photoluminescence in quantum dot-chain structures

Mazur

Dorogan

Ware

et al. 2012

Journal of Applied Physics

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Change of the photoluminescence (PL) polarization is studied by changing the excitation intensity and temperature for aligned In(Ga)As quantum dot (QD) structures with varying inter-dot distances grown by molecular beam epitaxy on semi-insulating GaAs (100) substrates. An unusual increase of the polarization ratio is observed by increasing the temperature and/or excitation intensity throughout a low temperature (T < 70 K) and low intensity (Iex < 1 W/cm2) range. This increase as well as the general behavior of the polarized PL are the results of the exciton dynamics and the peculiarities of the system morphology. They are due to the varying inter-dot distances which change the system from zero-dimensional comprised of isolated QDs to one-dimensional comprised of wire-like structures.

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A theoretical analysis of the optical absorption properties in one-dimensional InAs/GaAs quantum dot superlattices

Kotani

Birner

Lugli

et al. 2014

Journal of Applied Physics

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We present theoretical investigations of miniband structures and optical properties of InAs/GaAs one-dimensional quantum dot superlattices (1D-QDSLs). The calculation is based on the multi-band k·p theory, including the conduction and valence band mixing effects, the strain effect, and the piezoelectric effect; all three effects have periodic boundary conditions. We find that both the electronic and optical properties of the 1D-QDSLs show unique states which are different from those of well known single quantum dots (QDs) or quantum wires. We predict that the optical absorption spectra of the 1D-QDSLs strongly depend on the inter-dot spacing because of the inter-dot carrier coupling and changing strain states, which strongly influence the conduction and valence band potentials. The inter-miniband transitions form the absorption bands. Those absorption bands can be tuned from almost continuous (closely stacked QD case) to spike-like shape (almost isolated QD case) by changing the inter-dot spacing. The polarization of the lowest absorption peak for the 1D-QDSLs changes from being parallel to the stacking direction to being perpendicular to the stacking direction as the inter-dot spacing increases. In the case of closely stacked QDs, in-plane anisotropy, especially [110] and [11¯0] directions also depend on the inter-dot spacing. Our findings and predictions will provide an additional degree of freedom for the design of QD-based optoelectronic devices.

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Wire-like characteristics in stacked InAs/GaAs quantum dot superlattices for optoelectronic devices

Cited by 5 publications

References 15 publications

Vertical coupling in multiple stacks quantum-dot semiconductor optical amplifiers

Vertical coupling in multiple stacks quantum-dot semiconductor optical amplifiers

Effect of dimensionality and morphology on polarized photoluminescence in quantum dot-chain structures

A theoretical analysis of the optical absorption properties in one-dimensional InAs/GaAs quantum dot superlattices

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