A semi-continuum model on vibration frequency of silicon nanowires in &amp;lt;111&amp;gt; orientation

Hong Yu,Hong-Bo Chen

doi:10.1063/1.4954073

Abstract

In this article, a new semi-continuum model is built to describe the fundamental vibration frequency of the silicon nanowires in &lt;111&gt; orientation. The Keating potential model and the discrete nature in the width and the thickness direction of the silicon nanowires in &lt;111&gt; orientation are applied in the new semi-continuum model. Based on the Keating model and the principle of conservation of energy, the vibration frequency of the silicon nanowires with the triangle, the rhombus, and the hexagon cross sections are derived. It is indicated that the calculation results based on this new model are accordant with the simulation results of the software based on molecular dynamics (MD).

Highlights

As a basic unit of NEMS devices, the silicon nanowire has been found to possess some outstanding characteristics, such as very high frequency (GHz) and ultralow power consumption (10-17W).[1]
It is indicated that the calculation results based on this new model are accordant with the simulation results of the software based on molecular dynamics (MD)
The silicon nanowires are characterized by some experiments,[4] and theoretical studies which are based on continuum theory and some molecular dynamic softwares

Summary

Introduction

As a basic unit of NEMS devices, the silicon nanowire has been found to possess some outstanding characteristics, such as very high frequency (GHz) and ultralow power consumption (10-17W).[1]. The atomic behavior of the silicon nanowires is becoming more complex since the size effect, surface effect and quantum effect of the silicon material are significant.[2,3] So far the silicon nanowires are characterized by some experiments,[4] and theoretical studies which are based on continuum theory and some molecular dynamic softwares. Inherent continuum theory model can not accurately explain the vibration behavior of the silicon nanowires, and a huge computational resource is needed when the performance of silicon nanowires is simulated using molecular dynamics softwares. A new theoretical model is urgently to be established to precisely describe the vibration frequency of the silicon nanowires. Starting from Keating model, a semi-continuum model is built to calculate the vibration fundamental frequency of the silicon nanowires in orientation in this article. The law of conservation of energy is utilized to get the fundamental vibration frequency of the silicon nanowire

Methods

Results

Conclusion