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Combinatorial growth of Si nanoribbons.

Park TE, Lee KY, Kim I, Chang J, Voorhees P, Choi HJ - Nanoscale Res Lett (2011)

Bottom Line: These twins appear to drive the lateral growth by a reentrant twin mechanism.These twins also create a mirror-like crystallographic configuration in the anisotropic surface energy state and appear to further drive lateral saw-like edge growth in the < 112 > direction.These outcomes indicate that the Si NRs are grown by a combination of the two mechanisms of a Pt-catalyst-assisted VLS mechanism for longitudinal growth and a twin-assisted VS mechanism for lateral growth.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, Yonsei University, Seoul 120-749, South Korea. hjc@yonsei.ac.kr.

ABSTRACT
Silicon nanoribbons (Si NRs) with a thickness of about 30 nm and a width up to a few micrometers were synthesized. Systematic observations indicate that Si NRs evolve via the following sequences: the growth of basal nanowires assisted with a Pt catalyst by a vapor-liquid-solid (VLS) mechanism, followed by the formation of saw-like edges on the basal nanowires and the planar filling of those edges by a vapor-solid (VS) mechanism. Si NRs have twins along the longitudinal < 110 > growth of the basal nanowires that also extend in < 112 > direction to edge of NRs. These twins appear to drive the lateral growth by a reentrant twin mechanism. These twins also create a mirror-like crystallographic configuration in the anisotropic surface energy state and appear to further drive lateral saw-like edge growth in the < 112 > direction. These outcomes indicate that the Si NRs are grown by a combination of the two mechanisms of a Pt-catalyst-assisted VLS mechanism for longitudinal growth and a twin-assisted VS mechanism for lateral growth.

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Related in: MedlinePlus

HRTEM images of NRs. (a) HRTEM images showing the crystallographic orientation of the nanowire with saw-like edges in the course of the conversion to the NRs. The inset at the top shows interface between the basal nanowire and saw-like edge. The inset at the bottom shows the basal nanowire. The scale bar in the images is 5 nm. Corresponding SAED pattern recorded along the [-111] zone axis (b) and EDS spectrum (c).
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Figure 3: HRTEM images of NRs. (a) HRTEM images showing the crystallographic orientation of the nanowire with saw-like edges in the course of the conversion to the NRs. The inset at the top shows interface between the basal nanowire and saw-like edge. The inset at the bottom shows the basal nanowire. The scale bar in the images is 5 nm. Corresponding SAED pattern recorded along the [-111] zone axis (b) and EDS spectrum (c).

Mentions: To understand the crystal structure of the NRs, the saw-liked NRs were investigated by TEM, as shown in Figure 3. The selected-area electron diffraction (SAED) pattern recorded along [-111] zone axis (Figure 3b) indicated that the basal nanowires within the NRs grew along the < 110 > direction, whereas the saw-like edges grew along the < 112 > direction. As shown in the inset at the top of Figure 3a, no grain boundaries, misfit dislocations, or abrupt interfaces were observed at the interface between the basal nanowire and the saw-like edges. This indicates that the saw-like edges have an epitaxial relationship with the basal nanowires. The energy-dispersive spectroscopy (EDS) analysis presented in Figure 3c shows that the NRs is free from impurities, including Pt.


Combinatorial growth of Si nanoribbons.

Park TE, Lee KY, Kim I, Chang J, Voorhees P, Choi HJ - Nanoscale Res Lett (2011)

HRTEM images of NRs. (a) HRTEM images showing the crystallographic orientation of the nanowire with saw-like edges in the course of the conversion to the NRs. The inset at the top shows interface between the basal nanowire and saw-like edge. The inset at the bottom shows the basal nanowire. The scale bar in the images is 5 nm. Corresponding SAED pattern recorded along the [-111] zone axis (b) and EDS spectrum (c).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211989&req=5

Figure 3: HRTEM images of NRs. (a) HRTEM images showing the crystallographic orientation of the nanowire with saw-like edges in the course of the conversion to the NRs. The inset at the top shows interface between the basal nanowire and saw-like edge. The inset at the bottom shows the basal nanowire. The scale bar in the images is 5 nm. Corresponding SAED pattern recorded along the [-111] zone axis (b) and EDS spectrum (c).
Mentions: To understand the crystal structure of the NRs, the saw-liked NRs were investigated by TEM, as shown in Figure 3. The selected-area electron diffraction (SAED) pattern recorded along [-111] zone axis (Figure 3b) indicated that the basal nanowires within the NRs grew along the < 110 > direction, whereas the saw-like edges grew along the < 112 > direction. As shown in the inset at the top of Figure 3a, no grain boundaries, misfit dislocations, or abrupt interfaces were observed at the interface between the basal nanowire and the saw-like edges. This indicates that the saw-like edges have an epitaxial relationship with the basal nanowires. The energy-dispersive spectroscopy (EDS) analysis presented in Figure 3c shows that the NRs is free from impurities, including Pt.

Bottom Line: These twins appear to drive the lateral growth by a reentrant twin mechanism.These twins also create a mirror-like crystallographic configuration in the anisotropic surface energy state and appear to further drive lateral saw-like edge growth in the < 112 > direction.These outcomes indicate that the Si NRs are grown by a combination of the two mechanisms of a Pt-catalyst-assisted VLS mechanism for longitudinal growth and a twin-assisted VS mechanism for lateral growth.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Materials Science and Engineering, Yonsei University, Seoul 120-749, South Korea. hjc@yonsei.ac.kr.

ABSTRACT
Silicon nanoribbons (Si NRs) with a thickness of about 30 nm and a width up to a few micrometers were synthesized. Systematic observations indicate that Si NRs evolve via the following sequences: the growth of basal nanowires assisted with a Pt catalyst by a vapor-liquid-solid (VLS) mechanism, followed by the formation of saw-like edges on the basal nanowires and the planar filling of those edges by a vapor-solid (VS) mechanism. Si NRs have twins along the longitudinal < 110 > growth of the basal nanowires that also extend in < 112 > direction to edge of NRs. These twins appear to drive the lateral growth by a reentrant twin mechanism. These twins also create a mirror-like crystallographic configuration in the anisotropic surface energy state and appear to further drive lateral saw-like edge growth in the < 112 > direction. These outcomes indicate that the Si NRs are grown by a combination of the two mechanisms of a Pt-catalyst-assisted VLS mechanism for longitudinal growth and a twin-assisted VS mechanism for lateral growth.

No MeSH data available.


Related in: MedlinePlus