Elucidation of thermo-mechanical properties of silicon nanowires from a molecular dynamics perspective

Abstract

The thermo-mechanical properties of silicon nanowires are of great importance in the state of the art silicon technologies. Herein, thermal and mechanical properties of silicon nanowires along [110] direction are illustrated by a molecular dynamics approach using Tersoff potential. Different lengths ranging from 10 to 45 nm and cross section widths from 2.2 nm to 6.5 nm as well as different temperatures from 200 to 500 K were studied. In all the cases, the corresponding thermal conductivities of silicon nanowires were found to be much smaller than the bulk silicon counterpart, in the range of ~1–5 W/(m.K), and strongly dependent on size while less sensitive to temperature. The elastic modulus, fractural strain and stress were also investigated upon various size and temperatures indicating dramatically lower properties at higher temperature and as a result of nano-scaling. The presented findings on <110> silicon nanowires sheds further lights on the current understandings on thermo-mechanical behavior of silicon nanowires for applications such as in Li-ion batteries and provide complementary information for the relevant data bank.