Publications [#232886] of Jie Liu
search www.chem.duke.edu.Journal Articles
- Steiner, M; Freitag, M; Perebeinos, V; Tsang, JC; Small, JP; Kinoshita, M; Yuan, D; Liu, J; Avouris, P, "Phonon populations and electrical power dissipation in carbon nanotube transistors.", Nature nanotechnologyMay,, 2009, 4(5), 320-324 [doi].
(last updated on 2024/04/23)Abstract:
Carbon nanotubes and graphene are candidate materials for nanoscale electronic devices. Both materials show weak acoustic phonon scattering and long mean free paths for low-energy charge carriers. However, high-energy carriers couple strongly to optical phonons, which leads to current saturation and the generation of hot phonons. A non-equilibrium phonon distribution has been invoked to explain the negative differential conductance observed in suspended metallic nanotubes, while Raman studies have shown the electrical generation of hot G-phonons in metallic nanotubes. Here, we present a complete picture of the phonon distribution in a functioning nanotube transistor including the G and the radial breathing modes, the Raman-inactive zone boundary K mode and the intermediate-frequency mode populated by anharmonic decay. The effective temperatures of the high- and intermediate-frequency phonons are considerably higher than those of acoustic phonons, indicating a phonon-decay bottleneck. Most importantly, inclusion of scattering by substrate polar phonons is needed to fully account for the observed electronic transport behaviour.