Collapsing Carbon Nanotube Enhances Its Phonon Transport

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Carbon nanotubes (CNTs) undergo radial deformation in electronic devices, impacting their properties.
• Effective thermal management is crucial for high-performance CNT-based nanoelectronics.

Purpose of the Study:

• To investigate the effect of radial deformation on the thermal conductivity (κ) of CNTs.
• To understand the underlying mechanisms of thermal transport changes under stress.

Main Methods:

• Solving the phonon Boltzmann transport equation at 300 K.
• Simulating radial compression of a (6,6) carbon nanotube up to 18 GPa.

Main Results:

• Thermal conductivity (κ) of long CNTs increased up to six times upon radial compression.
• Radial compression stiffened specific phonon modes, weakening anharmonicity and increasing phonon relaxation time.
• Shorter CNTs (<1000 nm) exhibited a peak in κ due to a balance between increased relaxation time and phonon-boundary scattering.

Conclusions:

• Radial deformation significantly enhances thermal conductivity in CNTs by facilitating atomic coupling.
• An optimal stress level exists for maximizing CNT thermal conductivity, crucial for device performance.
• Findings provide insights for designing advanced CNT heterostructures with improved thermal management.