Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication
Strain-dependent scaling of excitons in carbon nanotubes
Wagner, C.ORC; Schuster, J.ORC; Schleife, A.ORC
Optical transitions in carbon nanotubes (CNTs) show a strong strain sensitivity, which makes them suitable for optical strain sensing at the nano-scale and for strain-tunable emitters. The origin of this effect is the dependence of the CNT band-gap on strain and chirality, which is well explored. However, there is no quantitative model for the strain dependence of optical transitions — which are subject to strong excitonic effects due to the quasi one-dimensional structure of CNTs.

One approach towards such a model is a parametrized description of the quasiparticle gap as well as the scaling relation of the exciton binding energy in CNTs given by Perebeinos et al [1]. However, the description of screening in the scaling relation is insufficient, since for CNTs, a one-dimensional wave-vector dependent dielectric function є(q) is required instead of an effective-medium dielectric constant є0.

We improve the approach by Perebeinos et al [1] by relating the screening physics in CNTs to the electronic transitions. The resulting model is fitted to electronic-structure calculations within many-body perturbation theory. This enables us to quantitatively predict the strain dependence of optical transitions for any CNT.

[1] V. Perebeinos et al., Phys. Rev. Lett. 92, 257402 (2004).
  • Lecture (Conference)
    DPG-Frühjahrstagung und EPS-CMD27, 12.-16.03.2018, Berlin, Deutschland

Downloads:

Publ.-Id: 28662 - Permalink