Modification of the phonon thermal conductivity in spatially confined semiconductor nanofilms under stress fields

Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education, PRC and Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University - Lanzhou, Gansu 730000, PRC

Corresponding authors: zhulinl03@lzu.cn xjzheng@lzu.edu.cn

Received: 2 August 2009
Accepted: 19 October 2009

Abstract

In the presence of stress fields, the phonon thermal conductivity of spatially confined semiconductor nanofilms is investigated. The phonon confinement and acoustoelastic effects are taken into account on the phonon dispersion in nanostructures. Specifically, within the continuum elasticity theory, we quantitatively analyze the phonon properties of confined Si nanofilms under stress fields. Numerical results reveal that stress can alter the phonon thermal conductivity of Si nanofilms remarkably. The effect of temperature and physical dimensions on phonon thermal conductivity has also been found to be sensitive to the presence of stress.