Tuning the morphology of self-assisted GaP nanowires

Leshchenko, Egor D.; Kuyanov, P; LaPierre, Ray; Дубровский, В. Г.

doi:10.1088/1361-6528/aab47b

Cited by 18 publications

(36 citation statements)

References 29 publications

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“…Inside this range, NWs grow with vertical sidewalls, while they taper at the small or inverse-taper at the large stable contact angle. Similar behavior is observed for self-catalyzed GaP NWs, with the vertical growth region shrinking to a narrow range around 123 • [35]. We have determined the small stable contact angle of In droplets 79 • .…”

Section: Resultssupporting

confidence: 73%

“…Our data clearly show that the axial growth rate is approximately proportional to F Sb , as demonstrated in Figure 2b. This is standard for self-catalyzed VLS growth [25,[32][33][34][35] and occurs because the catalyst droplet serves as a reservoir of group III atoms (In in our case) and the VLS growth conditions are always group V limited. Including the re-emitted flux of group V atoms scattered from the substrate surface or the neighboring NWs [32] does not change the linear scaling of the axial growth rate with group V flux.…”

Section: Resultsmentioning

confidence: 99%

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Growth of Self-Catalyzed InAs/InSb Axial Heterostructured Nanowires: Experiment and Theory

et al. 2020

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The growth mechanisms of self-catalyzed InAs/InSb axial nanowire heterostructures are thoroughly investigated as a function of the In and Sb line pressures and growth time. Some interesting phenomena are observed and analyzed. In particular, the presence of In droplet on top of InSb segment is shown to be essential for forming axial heterostructures in the self-catalyzed vapor-liquid-solid mode. Axial versus radial growth rates of InSb segment are investigated under different growth conditions and described within a dedicated model containing no free parameters. It is shown that widening of InSb segment with respect to InAs stem is controlled by the vapor-solid growth on the nanowire sidewalls rather than by the droplet swelling. The In droplet can even shrink smaller than the nanowire facet under Sb-rich conditions. These results shed more light on the growth mechanisms of self-catalyzed heterostructures and give clear route for engineering the morphology of InAs/InSb axial nanowire heterostructures for different applications.

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Section: Resultssupporting

confidence: 73%

Section: Resultsmentioning

confidence: 99%

Growth of Self-Catalyzed InAs/InSb Axial Heterostructured Nanowires: Experiment and Theory

et al. 2020

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“…Then, any increase (decrease) in the contact angle will immediately be compensated by the introduction of widening (narrowing) side facet, and the droplet volume changes by changing the NW top radius, as considered in the previous study. [18] This seems to be the case for ZB galliumcatalyzed GaP NWs according to the previous study, [19] where the NWs were tapered, vertical, or inverse tapered depending on the V/III flux ratio at the same contact angle around 123 . For GaAs NWs, the situation is very different (curve (b) for narrowing facet in Figure 1) and yields a rich variety of possible growth scenarios.…”

mentioning

confidence: 77%

Stabilization of the Morphology and Crystal Phase in Ensembles of Self‐Catalyzed GaAs Nanowires

Dubrovskiı̆

2019

Physica Rapid Research Ltrs

Self Cite

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Recent experimental data reveal the two stable contact angles of gallium droplets promoting the vapor–liquid–solid growth of GaAs nanowires, around 90° and 130°, with the critical angle of developing the truncated growth interface being smaller, but very close to 130°. Herein, a model is presented for the time evolution of the nanowire radii and preferred crystal structures in large ensembles of self‐catalyzed GaAs nanowires. The model qualitatively explains earlier experimental observations and even contradictory results. It is shown that all nanowires stabilize to a stationary radius and pure zincblende phase within the optimal range of V/III flux ratios. Lower V/III flux ratios yield pure zincblende phase without any radius stabilization, whereas higher V/III ratios lead to a limited focusing of the radius, polytypism, or even pure wurtzite phase of GaAs nanowires.

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“…In particular, the radial growth of self-catalyzed III-V NWs can be suppressed by increasing the V/III flux ratio as described in Refs. [59,63,64]. We plan to investigate this problem in future work.…”

Section: Discussionmentioning

confidence: 99%

Te incorporation and activation as n -type dopant in self-catalyzed GaAs nanowires

Hakkarainen

Piton

Fiordaliso

et al. 2019

Phys. Rev. Materials

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Dopant atoms can be incorporated into nanowires either via the vapor-liquid-solid mechanism through the catalyst droplet or by the vapor-solid growth on the sidewalls. Si is a typical n-type dopant for GaAs, but in nanowires it often suffers from a strongly amphoteric nature in the vapor-liquid-solid process. This issue can be avoided by using Te, which is a promising but less common alternative for n-type doping of GaAs nanowires. Here, we present a detailed investigation of Te-doped self-catalyzed GaAs nanowires. We use several complementary experimental techniques, such as atom probe tomography, off-axis electron holography, micro-Raman spectroscopy, and single-nanowire transport characterization, to assess the Te concentration, the free-electron concentration, and the built-in potential in Te-doped GaAs nanowires. By combing the experimental results with a theoretical model, we show that Te atoms are mainly incorporated by the vapor-liquid-solid process through the Ga droplet, which leads to both axial and radial dopant gradients due to Te diffusion inside the nanowires and competition between axial elongation and radial growth of nanowires. Furthermore, by comparing the free-electron concentration from Raman spectroscopy and the Te-atom concentrations from atom probe tomography, we show that the activation of Te donor atoms is 100% at a doping level of 4 × 10 18 cm −3 , which is a significant result in terms of future device applications.

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Tuning the morphology of self-assisted GaP nanowires

Cited by 18 publications

References 29 publications

Growth of Self-Catalyzed InAs/InSb Axial Heterostructured Nanowires: Experiment and Theory

Growth of Self-Catalyzed InAs/InSb Axial Heterostructured Nanowires: Experiment and Theory

Stabilization of the Morphology and Crystal Phase in Ensembles of Self‐Catalyzed GaAs Nanowires

Te incorporation and activation as n -type dopant in self-catalyzed GaAs nanowires

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