Ultrafast THz spectroscopy of carbon nanotube-graphene composites

Maria G. Burdanova, Alexey P. Tsapenko, Saeed Ahmad, Esko I. Kauppinen, James Lloyd-Hughes*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Mixed nanomaterial composites can combine the excellent properties of well-known low-dimensional nanomaterials. Here we highlight the potential of one-dimensional single-walled carbon nanotubes interfaced with two-dimensional graphene by exploring the composite’s ac conductivity and photoconductivity, and the influence of HAuCl4 doping. In the composite, the equilibrium terahertz conductivity from free carrier motion was boosted, while the localised plasmon peak shifted towards higher frequencies, which we attribute to shorter conductivity pathways in the composite. A negative terahertz photoconductivity was observed for all samples under 410 nm optical excitation and was reproduced by a simple model, where the Drude spectral weight and the momentum scattering rate were both lowered under photoexcitation. The composite had an enhanced modulation depth in comparison to reference carbon nanotube films, while retaining their characteristically fast (picosecond) response time. The results show that carbon nanotube-graphene composites offer new opportunities in devices by controlling charge carrier transport and tuning their optoelectronic properties.

Original languageEnglish
Article number405203
JournalNanotechnology
Volume34
Issue number40
DOIs
Publication statusPublished - 1 Oct 2023
MoE publication typeA1 Journal article-refereed

Keywords

  • carbon nanotube
  • conductivity
  • graphene
  • heterostructure
  • spectroscopy
  • THz

Fingerprint

Dive into the research topics of 'Ultrafast THz spectroscopy of carbon nanotube-graphene composites'. Together they form a unique fingerprint.

Cite this