Epitaxial growth of silver nanoislands on the surface of silicon nanowires in ambient air

Ren, Lu; Wang, Yewu; Wang, Wei; Gu, Lin; Sha, Jian

doi:10.1016/j.actamat.2014.07.030

Cited by 4 publications

(4 citation statements)

References 42 publications

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“…The size of the Ag sphere is bigger due to annealing in an O 2 atmosphere compared to that of an N 2 atmosphere as revealed from the SEM images. This is due to the fact that the mobility of Ag is enhanced on Si in the presence of O 2 atmosphere, due to the formation of a composite Ag m O which has higher mobility on Si compared to pure Ag resulting in an increased Ostwald ripening process, which finally leads to bigger shaped spherical Ag nanoparticles when annealed in O 2 atmosphere (Lu et al, 2014). The BSE image shown in the inset confirms the presence of smaller Ag nanoparticles on sidewalls of Si NW when annealed in N 2 atmosphere whereas no such smaller particle is seen when annealed in N 2 atmosphere.…”

Section: Resultsmentioning

confidence: 99%

Metal Nanoparticle-Decorated Silicon Nanowire Arrays on Silicon Substrate and their Applications

Roy

2019

Microsc Microanal

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Herein, we report an efficient method to produce silver (Ag) nanoparticle-decorated silicon (Si) nanowire (NW) arrays on a pyramidal Si (P-Si) substrate by using a pure chemical method and rapid thermal annealing in different atmospheres. A metal-assisted chemical etching technique was used to produce vertical Si NW arrays on pyramidal Si. The etching was observed to be heavily dependent on the substrate type. On planar Si (100), the etching was observed to occur in a uniform manner. However, the etching rate was observed to increase from the top to the base of the Si pyramid. The Si NWs produced from P-Si have zig-zag sidewalls as observed from high-resolution transmission electron microscopy images. However, for the same oxidant concentration, Si NWs produced from planar Si (100) consist of straight and amorphous sidewalls. Local variation of oxidant concentration is responsible for the formation of different sidewalls. The substrates are both surface-enhanced Raman scattering (SERS) active and hydrophobic. The hydrophobicity is due to the dual scale of roughness contributed to by both pyramidal and NW structures. Finite-difference time-domain simulation shows that the gap between two Ag spheres and also the gap between Si NWs and Ag spheres contributed to SERS enhancement.

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Section: Resultsmentioning

confidence: 99%

Metal Nanoparticle-Decorated Silicon Nanowire Arrays on Silicon Substrate and their Applications

Roy

2019

Microsc Microanal

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“…This is mainly attributed to the localized stress introduced by higher diffusion of Ag into Si, resulting in Si lattice defects . It is also well-known that the kinetics of the Ag particle is enhanced in the presence of O 2 . This is due to the fact that an adspecies Ag m O formed in the presence of O 2 atmosphere can transfer the Ag nanoparticle more easily compared to Ag adatoms due to their lower detachment barrier.…”

Section: Resultsmentioning

confidence: 99%

“…Due to reversible oxygen detachment-attachment process, Ag m O will decompose whenever they impinge on the surface of any other Ag nanoparticle. At high annealing temperature, however, Ag m O clusters have an increased likelihood of reacting with Si on the surface of Si . Atoms arriving at the surface and diffusing through it prefer to stick to the edges rather than to the facet of the island, which is possible if diffusion of particles through substrate is very much higher than through the island .…”

Section: Resultsmentioning

confidence: 99%

“…At high annealing temperature, however, Ag m O clusters have an increased likelihood of reacting with Si on the surface of Si. 42 Atoms arriving at the surface and diffusing through it prefer to stick to the edges rather than to the facet of the island, which is possible if diffusion of particles through substrate is very much higher than through the island. 43 This possibly leads to the formation of triangular particle in O 2 atmosphere along with Si etch pits.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Annealing Induced Morphology of Silver Nanoparticles on Pyramidal Silicon Surface and Their Application to Surface-Enhanced Raman Scattering

Roy

Maiti

Chini

2017

ACS Appl. Mater. Interfaces

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This paper reports on a simple and cost-effective process of developing a stable surface-enhanced Raman scattering (SERS) substrate based on silver (Ag) nanoparticles deposited on silicon (Si) surface. Durability is an important issue for preparing SERS active substrate as silver nanostructures are prone to rapid surface oxidation when exposed to ambient conditions, which may result in the loss of the enhancement capabilities in a short period of time. Here, we employ the galvanic displacement method to produce Ag nanoparticles on Si(100) substrate prepatterned with arrays of micropyramids by chemical etching, and subsequently, separate pieces of such substrates were annealed in oxygen and nitrogen environments at 550 °C. Interestingly, while nitrogen-annealed Si substrates were featured by spherical-shaped Ag particles, the oxygen annealed Si substrates were dominated by the formation of triangular shape particles attached with the spherical one. Remarkably, the oxygen-annealed substrate thus produced shows very high SERS enhancement compared to the either unannealed or nitrogen annealed substrate. The hitherto unobserved coexistence of triangular morphology with the spherical one and the gap between the two (source of efficient hot-spots) are the origin of enhanced SERS activity for the oxygen-annealed Ag particle-covered Si substrate as probed by the combined finite-difference time domain (FDTD) simulation and cathodoluminesensce (CL) experiment. As the substrate has already been annealed in an oxygen environment, further probability of oxidation is reduced in the present synthesis protocol that paves the way for making a novel long-lived thermally stable SERS substrate.

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A simple method of growing endotaxial silver nanostructures on silicon for applications in surface enhanced Raman scattering (SERS)

Roy

Chini

Satpati

2020

Applied Surface Science

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Epitaxial growth of silver nanoislands on the surface of silicon nanowires in ambient air

Cited by 4 publications

References 42 publications

Metal Nanoparticle-Decorated Silicon Nanowire Arrays on Silicon Substrate and their Applications

Metal Nanoparticle-Decorated Silicon Nanowire Arrays on Silicon Substrate and their Applications

Annealing Induced Morphology of Silver Nanoparticles on Pyramidal Silicon Surface and Their Application to Surface-Enhanced Raman Scattering

A simple method of growing endotaxial silver nanostructures on silicon for applications in surface enhanced Raman scattering (SERS)

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