Correlated Nanoscale Analysis of the Emission from Wurtzite versus Zincblende (In,Ga)As/GaAs Nanowire Core–Shell Quantum Wells

Lähnemann, Jonas; Hill, Megan O.; Herranz, Jesús; Marquardt, Oliver; Gao, Guanhui; Hassan, Ali Al; Davtyan, Arman; Hruszkewycz, S. O.; Holt, Martin V.; Huang, Chunyi; Calvo-Almazán, Irene; Jahn, U.; Pietsch, U.; Lauhon, Lincoln J.; Geelhaar, Lutz

doi:10.1021/acs.nanolett.9b01241

Cited by 12 publications

(22 citation statements)

References 70 publications

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“…Regarding NW structures, morphology, crystal defects and crystal phase can influence the local composition in various material systems. [7][8][9][10][11][12][13][14][15][16][17][18][19][20] For instance, Al tends to accumulate at the vertices of the self-formed, hexagonal shell in AlGaAs NWs due to its different facets. 7 Furthermore, the crystallinity could also impact the compositional distribution of NWs, as several studies found the preferential incorporation of some adatoms at the defect sites often leads to elemental segregation at the vicinity of twins, [11][12][13] which, on the other hand, indicates a means of composition modulation by controlling crystal twinning.…”

mentioning

confidence: 99%

Checked patterned elemental distribution in AlGaAs nanowire branches via vapor–liquid–solid growth

Boras

Fonseka

et al. 2020

Nanoscale

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confidence: 99%

Checked patterned elemental distribution in AlGaAs nanowire branches via vapor–liquid–solid growth

Boras

Fonseka

et al. 2020

Nanoscale

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“…The CL map in Figure 3b shows that the high energy emission originates from an approximately 350 nm long segment close to the top of the NWs, that we assign to a wurtzite (WZ) (In,Ga)As coaxial QW segment, as we have recently reported for similar structures without QDs. 21 The formation of a WZ segment on top of zincblende (ZB) GaAs NWs during core growth is related to the consumption of the Ga droplets prior to shell growth. The CL map in Figure 3c shows that the low energy emission originates from spatially localized states distributed along the NWs, consistent with its attribution to QD states.…”

Section: Resultsmentioning

confidence: 99%

Coaxial GaAs/(In,Ga)As Dot-in-a-Well Nanowire Heterostructures for Electrically Driven Infrared Light Generation on Si in the Telecommunication O Band

Herranz

Corfdir

Luna

et al. 2019

ACS Appl. Nano Mater.

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Core-shell GaAs-based nanowires monolithically integrated on Si constitute a promising class of nanostructures that could enable light emitters for fast inter-and intrachip optical connections. We introduce and fabricate a novel coaxial GaAs/(In,Ga)As dot-in-a-well nanowire heterostructure to reach spontaneous emission in the Si transparent region, which is crucial for applications in Si photonics. Specifically, we achieve room temperature emission at 1.27 µm in the telecommunication O band. The presence of quantum dots in the heterostructure is evidenced by a structural analysis based on scanning transmission electron microscopy. The spontaneous emission of these nanowire structures is investigated by cathodoluminescence and photoluminescence spectroscopy. Thermal redistribution of charge carriers to larger quantum dots explains the long wavelength emission achieved at room temperature. Finally, in order to demonstrate the feasibility of the presented nanowire heterostructures as electrically driven light emitters monolithically integrated on Si, a light emitting diode is fabricated exhibiting room-temperature electroluminescence at 1.26 µm.

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“…For all investigated NWs, SEM images and CL hyperspectral line scans were recorded before and after X-ray exposure using a Zeiss Ultra55 field-emission scanning electron microscope operated at an acceleration voltage of 5 kV with beam currents of 0.2-0.3 nA. For low-temperature CL measurements at 15 K, the scanning electron microscope is fitted with a Gatan MonoCL4 system and a He-cooled sample stage (Lä hnemann et al, 2019). To measure the as-grown NWs, the sample is cleaved close to the line of NWs and mounted at an angle of 45 , which is accounted for when plotting the CL.…”

Section: Methodsmentioning

confidence: 99%

“…The WZ polytype is formed in the upper part of the NW (see Fig. S5a in the supporting information) when the Ga droplet is consumed at the end of the core growth (Rieger et al, 2013;Lä hnemann et al, 2019). The WZ Bragg reflection undergoes a rapid thermal lattice expansion before disappearing after 92 min of exposure.…”

Section: Rsms Of the 111 Bragg Reflectionmentioning

confidence: 99%

Beam damage of single semiconductor nanowires during X-ray nanobeam diffraction experiments

Hassan¹,

Lähnemann²,

Davtyan³

et al. 2020

J Synchrotron Radiat

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Nanoprobe X-ray diffraction (nXRD) using focused synchrotron radiation is a powerful technique to study the structural properties of individual semiconductor nanowires. However, when performing the experiment under ambient conditions, the required high X-ray dose and prolonged exposure times can lead to radiation damage. To unveil the origin of radiation damage, a comparison is made of nXRD experiments carried out on individual semiconductor nanowires in their as-grown geometry both under ambient conditions and under He atmosphere at the microfocus station of the P08 beamline at the third-generation source PETRA III. Using an incident X-ray beam energy of 9 keV and photon flux of 1010 s−1, the axial lattice parameter and tilt of individual GaAs/In0.2Ga0.8As/GaAs core–shell nanowires were monitored by continuously recording reciprocal-space maps of the 111 Bragg reflection at a fixed spatial position over several hours. In addition, the emission properties of the (In,Ga)As quantum well, the atomic composition of the exposed nanowires and the nanowire morphology were studied by cathodoluminescence spectroscopy, energy-dispersive X-ray spectroscopy and scanning electron microscopy, respectively, both prior to and after nXRD exposure. Nanowires exposed under ambient conditions show severe optical and morphological damage, which was reduced for nanowires exposed under He atmosphere. The observed damage can be largely attributed to an oxidation process from X-ray-induced ozone reactions in air. Due to the lower heat-transfer coefficient compared with GaAs, this oxide shell limits the heat transfer through the nanowire side facets, which is considered as the main channel of heat dissipation for nanowires in the as-grown geometry.

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Correlated Nanoscale Analysis of the Emission from Wurtzite versus Zincblende (In,Ga)As/GaAs Nanowire Core–Shell Quantum Wells

Abstract: arXiv:1903.07372v4 [cond-mat.mes-hall]

Cited by 12 publications

References 70 publications

Checked patterned elemental distribution in AlGaAs nanowire branches via vapor–liquid–solid growth

Checked patterned elemental distribution in AlGaAs nanowire branches via vapor–liquid–solid growth

Coaxial GaAs/(In,Ga)As Dot-in-a-Well Nanowire Heterostructures for Electrically Driven Infrared Light Generation on Si in the Telecommunication O Band

Beam damage of single semiconductor nanowires during X-ray nanobeam diffraction experiments

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