Solid-State Limited Nucleation of NiSi/SiC Core-Shell Nanowires by Hot-Wire Chemical Vapor Deposition.

Mahdi Alizadeh,Muhammad Firdaus Bin Omar,Chang Fu Dee,Poh Choon Ooi,Najwa Binti Hamzan,Boon Tong Goh

doi:10.3390/ma12040674

Abstract

This work demonstrated a growth of well-aligned NiSi/SiC core-shell nanowires by a one-step process of hot-wire chemical vapor deposition on Ni-coated crystal silicon substrates at different thicknesses. The NiSi nanoparticles (60 to 207 nm) acted as nano-templates to initially inducing the growth of these core-shell nanowires. These core-shell nanowires were structured by single crystalline NiSi and amorphous SiC as the cores and shells of the nanowires, respectively. It is proposed that the precipitation of the NiSi/SiC are followed according to the nucleation limited silicide reaction and the surface-migration respectively for these core-shell nanowires. The electrical performance of the grown NiSi/SiC core-shell nanowires was characterized by the conducting AFM and it is found that the measured conductivities of the nanowires were higher than the reported works that might be enhanced by SiC shell layer on NiSi nanowires. The high conductivity of NiSi/SiC core-shell nanowires could potentially improve the electrical performance of the nanowires-based devices for harsh environment applications such as field effect transistors, field emitters, space sensors, and electrochemical devices.

Highlights

One-dimensional (1D) semiconductor nanostructures such as nanorods, nanotubes and nanowires have recently showed exciting scientific challenges and technological applications especially in nanoscale sensors, optoelectronic devices, energy generators, and storage devices [1,2,3].Highly metallic 1D NiSi nanowires possess excellent electrical, field emission and magnetic properties which make them a potential candidate for interconnectors, field emitters, functional micro-tips, biosensors, and micro-supercapacitors [4,5,6,7]
The nanowires are in high density and uniformly distributed on the substrate surfaces and it could be observed that the density of nanowires is directly proportional with the thickness of
This can be clearly shown on the formation of bumps along their lengths and the number of bump increases with increase in Ni thickness

Summary

Introduction

One-dimensional (1D) semiconductor nanostructures such as nanorods, nanotubes and nanowires have recently showed exciting scientific challenges and technological applications especially in nanoscale sensors, optoelectronic devices, energy generators, and storage devices [1,2,3].Highly metallic 1D NiSi nanowires possess excellent electrical, field emission and magnetic properties which make them a potential candidate for interconnectors, field emitters, functional micro-tips, biosensors, and micro-supercapacitors [4,5,6,7]. The superior ferromagnetic property with high coercivity of NiSi nanowires was reported to be attributed to its nanoscale and high Ni/Si ratio [8]. Their tiny nanoscale geometric feature and high aspect ratio, allow the nanowires to enhance the light-active region and provide a large surface area at a fixed volume for photovoltaic architecture [9,10]. The incorporation of SiC into the core-shell nanowires is motivated by its superior properties and the NiSi/SiC core-shell nanowires could potentially open a new direction of research into energy generation and storage applications [7]

Methods

Results

Conclusion