Surface-nitrogenation–induced thermal conductivity attenuation in silicon nanowires

Department of Physics and Materials Science, City University of Hong Kong - Hong Kong SAR, PRC

^a aprqz@cityu.edu.hk

Received: 28 June 2011
Accepted: 19 October 2011

Abstract

Using molecular dynamics simulations, we have calculated the thermal conductivity of nitrogen-terminated silicon nanowires (SiNWs). We found that nitrogen adsorption can remarkably bring down the thermal conductivity of SiNWs. This nitrogenation-induced drop in thermal conductivity arises mainly from the phonon scattering by defects near the surface and the suppression of some vibrational modes. Our simulation results clearly demonstrate the importance of surface chemistry or functionalization in tuning the thermal conductivity, which has profound implications for thermoelectric applications of SiNWs.