Strain-induced energy gap variation in ZnTe/ZnMgTe core/shell nanowires

Wojnar, P.; Zieliński, Michał; Janik, E.; Zaleszczyk, W.; Wojciechowski, Tomasz; Wojnar, R.; Szymura, M.; Kłopotowski, Ł.; Baczewski, L. T.; Pietruchik, A.; Wiater, M.; Kret, S.; Karczewski, G.; Wójtowicz, T.; Kossut, J.

doi:10.1063/1.4873355

Cited by 15 publications

(20 citation statements)

References 32 publications

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“…This preferential alignment can be caused by shear strain in the GaNAs shell created due to the lattice mismatch with the GaAs core layer that has a larger lattice constant. Indeed, as it was demonstrated in previous studies, [58][59][60] overall uniaxial anisotropy of nanowires has significant effects on strain in coherent core/shell structures from lattice mismatched semiconductors. In addition to the hydrostatic component, the predominant strain contribution was found to arise from the axial ε zz component.…”

Section: And D-f Respect-supporting

confidence: 56%

Strongly polarized quantum-dot-like light emitters embedded in GaAs/GaNAs core/shell nanowires

et al. 2016

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Recent developments in fabrication techniques and extensive investigations of the physical properties of III-V semiconductor nanowires (NWs), such as GaAs NWs, have demonstrated their potential for a multitude of advanced electronic and photonics applications. Alloying of GaAs with nitrogen can further enhance the performance and extend the device functionality via intentional defects and heterostructure engineering in GaNAs and GaAs/GaNAs coaxial NWs. In this work, it is shown that incorporation of nitrogen in GaAs NWs leads to formation of three-dimensional confining potentials caused by short-range fluctuations in the nitrogen composition, which are superimposed on long-range alloy disorder. The resulting localized states exhibit a quantum-dot like electronic structure, forming optically active states in the GaNAs shell. By directly correlating the structural and optical properties of individual NWs, it is also shown that formation of the localized states is efficient in pure zinc-blende wires and is further facilitated by structural polymorphism. The light emission from these localized states is found to be spectrally narrow (∼50-130 μeV) and is highly polarized (up to 100%) with the preferable polarization direction orthogonal to the NW axis, suggesting a preferential orientation of the localization potential. These properties of self-assembled nano-emitters embedded in the GaNAs-based nanowire structures may be attractive for potential optoelectronic applications.

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Section: And D-f Respect-supporting

confidence: 56%

Strongly polarized quantum-dot-like light emitters embedded in GaAs/GaNAs core/shell nanowires

et al. 2016

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“…The PL spectrum at 5K [ Fig. 2(a)] exhibits an emission peak centered at 2.35 eV, which is related to the exciton recombination in the ZnTe core, 19,29,31 and a second one at 1.96 eV, which is attributed to the quantum dot luminescence. The presence of the Mn atoms significantly broadens the emission from the QD because of the magnetization fluctuations randomly shifting the exciton line in time through the giant Zeeman effect.…”

Section: Introductionmentioning

confidence: 99%

Light-hole exciton in a nanowire quantum dot

et al. 2017

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Quantum dots inserted inside semiconductor nanowires are extremely promising candidates as building blocks for solid-state based quantum computation and communication. They provide very high crystalline and optical properties and offer a convenient geometry for electrical contacting. Having a complete determination and full control of their emission properties is one of the key goals of nanoscience researchers. Here we use strain as a tool to create in a single magnetic nanowire quantum dot a light-hole exciton, an optically active quasiparticle formed from a single electron bound to a single light hole. In this frame, we provide a general description of the mixing within the hole quadruplet induced by strain or confinement. A multi-instrumental combination of cathodoluminescence, polarisation-resolved Fourier imaging and magneto-optical spectroscopy, allow us to fully characterize the hole ground state, including its valence band mixing with heavy hole states. arXiv:1612.01563v1 [cond-mat.mes-hall]

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“…Two features appear on the monochromatic images (a) and on the spectra (b): a broad structured band around 2300 meV, visible over the whole NW, and an instrumentally-broadened line at 1980 nm, detected only at the tip. The high-energy side of the green band coincides with the emission of ZnTe NWs with a (Zn,Mg)Te shell, i.e., the ZnTe exciton shifted by the strain induced by the (Zn,Mg)Te shell [23,25,26]. In addition, a low-energy tail is observed in Fig.…”

Section: Resultsmentioning

confidence: 55%

Probing the light hole/heavy hole switching with correlated magneto-optical spectroscopy and chemical analysis on a single quantum dot

Artioli¹,

Rueda-Fonseca²,

Moratis³

et al. 2019

Nanotechnology

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A whole series of complementary studies have been performed on the same, single nanowire containing a quantum dot: cathodoluminescence spectroscopy and imaging, micro-photoluminescence spectroscopy under magnetic field and as a function of temperature, and energy-dispersive X-ray spectrometry and imaging. The ZnTe nanowire was deposited on a Si 3 N 4 membrane with Ti/Al patterns. The complete set of data shows that the CdTe quantum dot features the heavy-hole state as a ground state, although the compressive mismatch strain promotes a light-hole ground state as soon as the aspect ratio is larger than unity (elongated dot). A numerical calculation of the whole structure shows that the transition from the heavy-hole to the light-hole configuration is pushed toward values of the aspect ratio much larger than unity by the presence of a (Zn,Mg)Te shell, and that the effect is further enhanced by a small valence band offset between the semiconductors in the dot and around it.

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Strain-induced energy gap variation in ZnTe/ZnMgTe core/shell nanowires

Cited by 15 publications

References 32 publications

Strongly polarized quantum-dot-like light emitters embedded in GaAs/GaNAs core/shell nanowires

Strongly polarized quantum-dot-like light emitters embedded in GaAs/GaNAs core/shell nanowires

Light-hole exciton in a nanowire quantum dot

Probing the light hole/heavy hole switching with correlated magneto-optical spectroscopy and chemical analysis on a single quantum dot

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