Monte Carlo simulation of hot optical phonon decay in a carbon nanotube

Reduced dimensional materials, such as carbon nanotubes (CNTs), are expected to exhibit relatively large optical phonon decay times. Scattering and thus thermalization of CNT phonon modes proceeds slowly due to a reduction in crystal momentum conserving final wavevector states. The presence of non-equilibrium optical phonons may have pronounced effects on the electrical, thermal, and optical properties of carbon nanotubes. It is widely believed that such hot phonons lead to conductance degradation, negative differential conductance, and enhanced thermal breakdown of suspended CNTs. Furthermore, absorbtion of hot optical phonons by conducting carriers would significantly alter device characteristics in the low-field ballistic limit. Thermal properties are also effected as the slow decay of hot phonons is expected to lead to reduced thermal diffusivity, and the development of inhomogeneous heating within a nanotube.