Tuning the thermal conductivity of wurtzite CdSe nanowires: effects of size, strain, torsion and temperature

ABSTRACT

The thermal transport of wurtzite CdSe nanowires (NWs) is studied by means of nonequilibrium molecular dynamics simulations. It is found that the length, diameter and strain can tune the thermal conductivity of CdSe NWs effectively, while the thermal conductivity exhibits insensitivity to torsion. The results indicate that the thermal conductivity of the CdSe NWs varies with the diameter approximately in the range of 13.8–17.7 W·m⁻¹·K⁻¹. The underlying mechanism is discussed by calculating the phonon power spectral density. The results show that the thermal transport is dominated by the centre atoms of NW, and high-frequency phonons contribute a lot to the thermal transport. Moreover, both tensile strain and compression strain can effectively suppress the thermal transport of CdSe NWs. The minimum thermal conductivity for the tensile strain and compression strain are 9.65 and 2.89 W·m⁻¹·K⁻¹, which are about 35% and 81% less than that of the unstrained structure.

KEYWORDS:

• Thermal conductivity
• CdSe nanowire
• strain
• tuning effect

Disclosure statement

No potential conflict of interest was reported by the author(s).