Ultrafast THz spectroscopy of carbon nanotube-graphene composites

No Thumbnail Available
Access rights
embargoedAccess
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal
Embargo ends: 2024-07-19

Other link related to publication
Date
2023-10-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
Series
Nanotechnology, Volume 34, issue 40
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.
Description
Funding Information: The authors would like to acknowledge M I Paukov, A S Slavich, A V Arsenin and V S Volkov for informative discussions and support. The authors also acknowledge Dr Hua Jiang and Dr Qiang Zhang from Aalto University for the help and assistance with TEM image acquisition and synthesis experiments, respectively. This research was supported by the Academy of Finland via the CNT-stress project (316572). A P Ts acknowledges the EDUFI Fellowship (No. TM-19-11079) from the Finnish National Agency for Education and the Magnus Ehrnrooth Foundation (the Finnish Society of Sciences and Letters) for personal financial support. Funding Information: The authors would like to acknowledge M I Paukov, A S Slavich, A V Arsenin and V S Volkov for informative discussions and support. The authors also acknowledge Dr Hua Jiang and Dr Qiang Zhang from Aalto University for the help and assistance with TEM image acquisition and synthesis experiments, respectively. This research was supported by the Academy of Finland via the CNT-stress project (316572). A P Ts acknowledges the EDUFI Fellowship (No. TM-19-11079) from the Finnish National Agency for Education and the Magnus Ehrnrooth Foundation (the Finnish Society of Sciences and Letters) for personal financial support. Publisher Copyright: © 2023 IOP Publishing Ltd
Keywords
carbon nanotube, conductivity, graphene, heterostructure, spectroscopy, THz
Other note
Citation
Burdanova , M G , Tsapenko , A P , Ahmad , S , Kauppinen , E I & Lloyd-Hughes , J 2023 , ' Ultrafast THz spectroscopy of carbon nanotube-graphene composites ' , Nanotechnology , vol. 34 , no. 40 , 405203 . https://doi.org/10.1088/1361-6528/ace1f6