Adjusting the Morphology and Properties of SiC Nanowires by Catalyst Control.

Chuchu Guo,Laifei Cheng,Fang Ye,Qing Zhang

doi:10.3390/ma13225179

Abstract

We report on the growth of SiC nanowires on a single crystal Si substrate by pyrolysis of polycarbosilane and using two catalyst (Al2O3 and Ni) films with different thickness (2, 4, and 6 nm). The catalyst films were deposited on the Si substrate, and the SiC nanowires were grown according to two mechanisms, i.e., the oxide-assisted growth mechanism and vapor- liquid-solid mechanism. As a result, pearl-chain-like SiC nanowires and straight SiC nanowires were obtained. The prepared nanowires exhibited excellent photoluminescence properties, emission spectra displaying two emission peaks at 395 and 465 nm, and have good thermal stability below 1000 °C. The experimental results revealed the importance of the catalyst in controlling the morphology and properties of SiC nanowires.

Highlights

In the nanometer scale, the surface effect, small size effect, quantum size effect and macroscopic tunneling effect dramatically change the physical and chemical properties of materials [1,2,3,4].For instance, SiC nanowires, a non-oxide ceramic material, attracted great interest as a highly promising nanomaterial for many industrial applications due to their superior electric and mechanical properties, as well as heat, corrosion, and high temperature oxidation resistance [5,6,7]
Oxides are commonly used as catalysts to grow nanowires through the oxide-assisted growth (OAG) mechanism, whereas transition metals are often used as catalysts for the growth of nanomaterials by the vapor-liquid-solid (VLS) mechanism
The obtained products were named as A1, A2, A3, respectively for the samples prepared with Al2 O3 catalyst film at a thickness of 2, 4, and 6 nm, and N1, N2, N3, respectively for the samples prepared with Ni catalyst film at a thickness of 2, 4, and 6 nm

Summary

Introduction

The surface effect, small size effect, quantum size effect and macroscopic tunneling effect dramatically change the physical and chemical properties of materials [1,2,3,4]. SiC nanowires, a non-oxide ceramic material, attracted great interest as a highly promising nanomaterial for many industrial applications due to their superior electric and mechanical properties, as well as heat, corrosion, and high temperature oxidation resistance [5,6,7]. These unique properties enable SiC nanowires to be used as ideal candidates for nanodevices for sensing and biosensing applications, or in composite materials as a reinforcement [8,9,10]. This work is focused on the preparation of SiC nanowires, displaying different morphologies, by changing the type and content of catalysts loaded on the substrate. The nanowires were grown on the single crystal silicon substrate by VLS and OAG mechanisms. The growth mechanisms of SiC nanowires were described in detail, providing fundamental knowledge for the rational control of the morphology of SiC nanowires

Synthesis of Samples

Characterization of Samples

3.3.Results

Schematic

Conclusions