Optical emission from carbon nanotube transistors (CNTFETs) has recently attracted significant attention due to its potential applications. In this paper, we use a self-consistent numerical solution of the Boltzmann transport equation in the presence of both phonon and exciton scattering to present a detailed study of the operation of a partially suspended CNTFET light emitter, which has been discussed in a recent experiment. We determine the energy distribution of hot carriers in the CNTFET, and, as reported in the experiment, observe localized generation of excitons near the trench-substrate junction and an exponential increase in emission intensity with a linear increase in current versus gate voltage. We further provide detailed insight into device operation, and propose optimization schemes for efficient exciton generation; a deeper trench increases the generation efficiency, and use of high-k substrate oxides could lead to even larger enhancements.
@article{arxiv.0805.0246,
title = {Computational study of exciton generation in suspended carbon nanotube transistors},
author = {Siyuranga O. Koswatta and Vasili Perebeinos and Mark S. Lundstrom and Phaedon Avouris},
journal= {arXiv preprint arXiv:0805.0246},
year = {2008}
}