English

Multiple Exciton Generation in Chiral Carbon Nanotubes: Density Functional Theory Based Computation

Mesoscale and Nanoscale Physics 2017-11-22 v2 Materials Science

Abstract

We use Boltzmann transport equation (BE) to study time evolution of a photo-excited state in a nanoparticle including phonon-mediated exciton relaxation and the multiple exciton generation (MEG) processes, such as exciton-to-biexciton multiplication and biexciton-to-exciton recombination. BE collision integrals are computed using Kadanoff-Baym-Keldysh many-body perturbation theory (MBPT) based on density functional theory (DFT) simulations, including exciton effects. We compute internal quantum efficiency (QE), which is the number of excitons generated from an absorbed photon in the course of the relaxation. We apply this approach to chiral single-wall carbon nanotubes (SWCNTs), such as (6,2), and (6,5). We predict efficient MEG in the (6,2) and (6,5) SWCNTs within the solar spectrum range starting at the 2Eg2 E_g energy threshold and with QE reaching 1.6\sim 1.6 at about 3Eg,3 E_g, where EgE_g is the electronic gap.

Keywords

Cite

@article{arxiv.1707.06521,
  title  = {Multiple Exciton Generation in Chiral Carbon Nanotubes: Density Functional Theory Based Computation},
  author = {Andrei Kryjevski and Deyan Mihaylov and Svetlana Kilina and Dmitri Kilin},
  journal= {arXiv preprint arXiv:1707.06521},
  year   = {2017}
}

Comments

20 pages, 6 figures. 7/20/2017: arXiv admin note: substantial text overlap with arXiv:1703.04693. In v2 text changed to avoid text overlap with our earlier work on the same subject arXiv:1703.04693

R2 v1 2026-06-22T20:52:57.602Z