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

摘要

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_1), the rate of energy transfer between the electronic system and the lattice as a function of electron and lattice temperatures T_e and T_1 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 λ. The experimentally obtained value for λ/Θ_D~2, where Θ_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.