Phonon localization and resonance in thermal transport of pillar-based GaAs nanowires.

Exploring the possibility of nanostructures to modulate thermal conductivity (TC) contributes to promote a deeper comprehension of phonon diffusion and transport processes with the design of thermally insulated devices with high ZT values, and the GaAs nanowires (NWs) widely used in optoelectronic and microelectronic devices exhibit nondiffusive phonon thermal transport phenomena attributed to size effects, while ignoring the wave effects of phonons. Here, we simulate the TC of pillar-based GaAs NWs using non-equilibrium molecular dynamics and Monte Carlo simulations. The spatial distribution of density of states, temperature and heat flow distribution clouds, phonon participation rate, dispersion curves and phonon transmittance of atoms were calculated to investigate the phonon thermal transport processes in pillar-based NWs.