In situ observation of interaction between grain boundaries during directional solidification of Si

Chuang, Lu-Chung; Maeda, Kensaku; Morito, Haruhiko; Shiga, Kiyoshi; Miller, W.; Fujiwara, Kozo

doi:10.1016/j.scriptamat.2018.01.020

Cited by 17 publications

(5 citation statements)

References 19 publications

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“…A major issue shared by all techniques without exception is to control and lower the density of strained regions of the crystal structure that are at the origin of dislocation emission. Few works are available in the literature discussing those phenomena and studying grain formation, grain boundary interaction [15][16][17][18][19] and dislocation generation mechanisms [20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Strain building and correlation with grain nucleation during silicon growth

et al. 2019

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This work is dedicated to the grain structure formation in silicon ingots with a particular focus on the crystal structure strain building and its implication in new grain nucleation process. The implied mechanisms are investigated by advanced in situ X-ray imaging techniques during silicon directional solidification. It is shown that the grain structure formation is mainly driven by Σ3 <111> twin nucleation. Grain competition phenomena occurring during the growth process lead to the creation of higher order twin boundaries, localised strained areas and associated crystal structure deformation. On the one hand, it is demonstrated that local strain building can be directly related to the characteristics of the twin boundaries created during silicon growth due to grain competition. On the other hand, space restriction due to competition during growth can be at the origin of local strain building as well. Finally, the accumulation of all these factors generating strain is responsible for spontaneous new grain nucleation. When occurring, both grain nucleation and subsequent grain structure reorganisation contribute to lower the strain in the growing ingot.It is demonstrated as well that the local distribution of the strained areas created during silicon growth is retrieved after cooling down, from melting temperature to room temperature, on top of an additional larger scale deformation of the sample due to the cooling down only.

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Section: Introductionmentioning

confidence: 99%

Strain building and correlation with grain nucleation during silicon growth

et al. 2019

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“…Although we can generally explain the relationship between the bending modulus and AC:ZZ ratio, the turning points are slightly different. A possible reason is the interaction between the grain boundaries, which depends on the distance of two grain boundaries [34,35]. The nonlocal interactions in grain boundaries were reinforced as the grain boundaries get closer, leading higher mechanical modulus [34].…”

Section: Resultsmentioning

confidence: 99%

Engineering the flexibility and elastic modulus of graphene by heterojunctions

Liu,

Li,

Jiang

2024

Phys. Scr.

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Graphene shows both superior flexibility and excellent mechanical strength. The fabricated graphene samples usually contain various defects like grain boundaries, which can either enhance or weaken the mechanical strength of graphene. So, exploring the effects of grain boundaries on the flexibility of graphene is useful in designing graphene-based flexible devices. Employing the first-principles calculation, flexibilities of graphene heterojunctions were studied, aiming to tailor the flexibility of graphene by heterojunctions. Here, by connecting armchair (AC) and zigzag (ZZ) graphene through grain boundaries, graphene heterojunctions with tunable AC to ZZ ratio were constructed. It was found that bending moduli, as well as Young’s moduli, of graphene heterojunctions are lower than the pristine graphene and can be further tailored by the AC to ZZ ratio, making graphene heterojunctions more flexible than graphene. Particularly, changing the AC to ZZ ratio can even alter the relative flexibility of graphene heterojunctions in different directions. Therefore, graphene heterojunction provides an approach to engineer the flexibility of graphene, which is helpful in understanding the mechanical properties of two-dimensional materials and designing the flexible devices.

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“…In situ observation of melt growth is an effective tool for understanding the growth mechanism. 21,22) Protrusion growth was observed in situ until the path was burned out using a long-working-distance optical microscope. The protrusions were analyzed using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS).…”

Section: Introductionmentioning

confidence: 99%

In situ observation of formation of Si protrusions by local melting of a Si narrow current path using resistive heating together with electron beam irradiation

Nishimura¹,

Tomitori²

2022

Jpn. J. Appl. Phys.

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Silicon (Si) protrusions were grown by local surface melting and resolidified on a Si(111) fragment with a narrow current path that was fabricated using a microgrinder at the center of the fragment. The narrow path was resistively heated by passing a current through it until it burned. The surface of the narrow path and fragment gradually melted with increasing current, and the melted Si started to flow from the narrow path to its sides owing to the surface tension of the melted Si. When the fragment surface near the path was locally irradiated with an electron-beam, melted Si accumulated in the irradiation region, resulting in Si protrusions of ~600 µm in height. The formation mechanism of the Si protrusion was discussed based on in-situ optical microscope observations up to the burn-out of the Si narrow path.

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In situ observation of interaction between grain boundaries during directional solidification of Si

Cited by 17 publications

References 19 publications

Strain building and correlation with grain nucleation during silicon growth

Strain building and correlation with grain nucleation during silicon growth

Engineering the flexibility and elastic modulus of graphene by heterojunctions

In situ observation of formation of Si protrusions by local melting of a Si narrow current path using resistive heating together with electron beam irradiation

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