Formation of “negative” silicon whiskers

Небольсин, В. А.; Dunaev, A. I.; Vorob’ev, A. Yu.; Samofalova, A. S.; Zenin, V. V.

doi:10.1134/s002016851708012x

Cited by 4 publications

(5 citation statements)

References 8 publications

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“…If the shape of the front or the TL is concave, then the volume of the spherical segment of the critical nucleus is clearly smaller so that its formation should occur with less overcooling. This fact is experimentally confirmed by the nucleus formation on either the “concavities” of the surface defects that have some “incoming” angles or on the “concave” TL at the NW growth. , …”

Section: Resultsmentioning

confidence: 99%

“…Therefore, at temperature temperature T above the temperature T E , ΔT = T E − T < 0 (the negative curvature during overheating of the liquid). 28 During the formation of the crystalline nucleus under the catalyst drop, the energy gain is related to the fact that the Gibbs energy of the new phase is significantly less than the energy of the original curved liquid phase, while the energy loss is attributable to the formation of the interface surface between the nucleus and the liquid phase (Figures 7 and 8). As the size of the nucleus increases, r N , the energy passes through the maximum at the critical nucleus radius r N * (Figure 7).…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, at temperature T E – Δ T , the critical radius r N * can be found from , or which gives Figure demonstrates the relationship between Δ T and r N * for two different radii of the catalyst droplet R . The upper branches (for positive values of Δ T and r N * ) correspond to the growth of NWs from the supercooled liquid-phase catalyst, and the lower branches (for negative values of Δ T and r N * ) relate to the formation of “negative” NWs from the liquid phase at a temperature T above the temperature T E , Δ T = T E – T < 0 (the negative curvature during overheating of the liquid) …”

Section: Resultsmentioning

confidence: 99%

“…This fact is experimentally confirmed by the nucleus formation on either the "concavities" of the surface defects that have some "incoming" angles or on the "concave" TL at the NW growth. 19,28 Let us define the relationship between the angles ψ and φ 0. To do this, we express from the second equation of the system of eq 16 the angle ψ…”

Section: Formation Of the Curved Crystallization Frontmentioning

confidence: 99%

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About the Shape of the Crystallization Front of the Semiconductor Nanowires

et al. 2023

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During the nanowire (NW) formation, the growth steps reaching the crystallization front (CF) under the catalytic drop are either absorbed by the three-phase line or accumulated in front of it, curving the surface of the front. In this paper, we have analyzed the conditions leading to a change of shape of the crystallization front of the NWs under the catalyst drop as well as the reasons for the formation of atomically smooth (singular) and curved (nonsingular) regions. A model explaining the curvature of the crystallization front under the drop in the process of NW growth is proposed. The model demonstrates that under conditions of good wettability of the crystalline surface with a catalytic liquid and nucleation at regular places of the growing NW face, a metastable equilibrium at the CF near the three-phase line is achieved due to the thermodynamic size effect of reduction of overcooling (supersaturation). This metastable equilibrium results in the curvature of the CF. The CF curvature depends on the NW radius and the level of overcooling (supersaturation) in the droplet. During this process, the low-index inclined facets adjacent to the wetting perimeter of the catalyst drop may appear on the curved CF.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Formation Of the Curved Crystallization Frontmentioning

confidence: 99%

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About the Shape of the Crystallization Front of the Semiconductor Nanowires

et al. 2023

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“…For the internal surfaces of nanotubes, grown by the VLS process, [ 31 ] and for the “negative” NWs [ 32 ] the TPL is concave with respect to the crystal. In this case, for the oblique closed‐packed face to appear on a sidewall surface, the inverse condition is necessary to be satisfied, i.e.,

\xi &amp;#x00026;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0

.…”

Section: Resultsmentioning

confidence: 99%

Vapor–Liquid–Solid Growth of Nanowires under the Conditions of External Faceting

Levchenko,

Nebol'sin,

Yuryev

et al. 2023

Physica Status Solidi (b)

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In this paper, we have considered the processes that occur at the interfaces during the nanowires (NWs) growth by the Vapor→Droplet, Liquid→Solid mechanism (VLS), and how that leads to the faceting of the sidewall surface of the NWs. It is shown that faceting is possible only when the Wetting Scenario of the VLS‐growth of the NWs is accomplished due to the exit of the oblique closed packed faces to the sidewall surface of the NWs. Those oblique closed‐packed faces emerge at the crystallization front near the triple phase line. The faceting of the sidewall surface of the NWs can be controlled (i) by changing the contact angle of the catalyst droplet on the top of the NWs with the appropriate catalysts; (ii) by introducing the impurities into the gas phase, which decreases the free surface energy of the catalyst droplet or (iii) by changing the temperature.This article is protected by copyright. All rights reserved.

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