Temperature Dependence of Electron to Lattice Energy-Transfer in Single-Wall Carbon Nanotube Bundles

TL;DR

This study investigates how electron-to-lattice energy transfer in single-wall carbon nanotube bundles varies with temperature, revealing a T^5 dependence and implications for electron-phonon scattering times.

Contribution

It provides the first direct measurement of the temperature dependence of energy transfer rates in SWNT bundles using femtosecond spectroscopy, highlighting a T^5 relationship.

Findings

H(T_e,T_l) follows a T^5 dependence

Electron-phonon scattering times can exceed 1.5 ps at room temperature

Results relate to the e-ph mass enhancement parameter lambda

Abstract

The electron-phonon coupling strength in single-wall carbon nanotube (SWNT) bundles has been studied directly in the time-domain by femtosecond time-resolved photoelectron spectroscopy. We have measured the dependence of H(T_e,T_l), the rate of energy-transfer between the electronic system and the lattice as a function of electron and lattice temperatures T_e and T_l. The experiments are consistent with a T^5 dependence of H on the electron- and lattice-temperatures, respectively. The results can be related to the e-ph mass enhancement parameter lambda. The experimentally obtained value for lambda/theta_D^2, where theta_D is the Debye temperature, suggests that e-ph scattering times at the Fermi level of SWNT bundles can be exceptionally long, exceeding 1.5 ps at room temperature.