Indium segregation and In–Ga inter-diffusion effects on the photoluminescence measurements and nonlinear optical properties in lens-shaped InxGa1-xAs/GaAs quantum dots

Choubani, M.; Maâref, H.; Saidi, F.

doi:10.1016/j.jpcs.2021.110360

Cited by 7 publications

(2 citation statements)

References 33 publications

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“…clusters is expected to localise the electrons, and the change of the local density of states(DOS)would degrade the optical properties. [5][6][7] On the practical side, highangle annular dark-field scanning transmission electron microscopy (HAADF-STEM) provides the possibility of observing In segregation or precipitation at the subnanometre scale because HAADF-STEM is very sensitive to changes in average atomic numbers (Z-contrast), which allows the observation of In segregation 8 and compositional variations. 9 In InGaAs/InAlAs quantum wells, due to the large atomic number of In, segregation of In atoms increases the local intensity in HAADF images, which allows a direct mapping of In-rich nanoclusters.…”

Section: Introductionmentioning

confidence: 99%

“…However, the growth of high In content III–V nitrides quantum wells often suffers from In segregation during growth 1–4 . The formation of In‐rich semiconducting clusters or even metallic In clusters is expected to localise the electrons, and the change of the local density of states(DOS)would degrade the optical properties 5–7 . On the practical side, high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) provides the possibility of observing In segregation or precipitation at the sub‐nanometre scale because HAADF‐STEM is very sensitive to changes in average atomic numbers ( Z ‐contrast), which allows the observation of In segregation 8 and compositional variations 9 .…”

Section: Introductionmentioning

confidence: 99%

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The evolution of indium precipitation in gallium focused ion beam prepared samples of InGaAs/InAlAs quantum wells under electron beam irradiation

Liu,

Dong,

et al. 2023

Journal of Microscopy

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Gallium ion (Ga+) beam damage induced indium (In) precipitation in indium gallium arsenide (InGaAs)/indium aluminium arsenide (InAlAs) multiple quantum wells and its corresponding evolution under electron beam irradiation was investigated by valence electron energy loss spectroscopy (VEELS) and high‐angle annular dark‐field imaging (HAADF) in scanning transmission electron microscopy (STEM). Compared with argon ion milling for sample preparation, the heavier projectiles of Ga+ ions pose a risk to trigger In formation in the form of tiny metallic In clusters. These are shown to be sensitive to electron irradiation and can increase in number and size under the electron beam, deteriorating the structure. Our finding reveals the potential risk of formation of In clusters during focused ion beam (FIB) preparation of InGaAs/InAlAs quantum well samples and their subsequent growth under STEM‐HAADF imaging, where initially invisible In clusters of a few atoms can move and swell during electron beam exposure.Lay description: In this paper, the evolution of Ga+ implantation induced In precipitation in InGaAs/InAlAs multiple quantum wells under electron beam irradiation was investigated by valence electron energy loss spectroscopy (VEELs), energy dispersive X‐ray spectroscopy (EDXs) and high‐angle annular dark‐field (HAADF) imaging technique based in a probe aberration corrected scanning transmission electron microscope. In contrast to Ar+ ion bombardment, the projectile of focused Ga+ ions is able to trigger the clustering of In interstitials in InGaAs/InAlAs multiple quantum wells, which allows the formation of metallic In precipitates. Afterwards, by exploiting an extensive electron beam rastering on the region of In precipitation, the increase of electron irradiation time could lead to a pronounced swelling of In cluster size. Especially for the region contains In precipitates of several atoms, where the morphology of In cluster is invisible in atomic image. The continuous electron irradiation could give rise to the promotion of In clustering, allowing the structure of In precipitates been resolved by HAADF image. Our finding reveals the potential risk of formation of In precipitates during focused Ga+ ion beam bombarded InGaAs/InAlAs semiconductors and the subsequent evolution of In clustering under electron beam rastering. These findings emphasise the need for caution when studying FIB prepared In‐based III–V quantum well specimens using TEM even in the In(Ga,Al)As system, as the initially formed In‐rich clusters are so small they can remain invisible for some time.

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