High-frequency impedance of single-walled carbon nanotube networks on transparent flexible substrate

• Published in: Physica Status Solidi. B: Basic Solid State Physics Vol. 251; no. 12; pp. 2461 - 2465
• Main Authors: Iqbal, Muhammad Zahir, Pérez-Puigdemont, Jordi, Eom, Jonghwa, Ferrer-Anglada, Nuria
• Format: Journal Article Publication
• Language: English
• Published: Blackwell Publishing Ltd 01.12.2014
• Subjects: ac conductivity; carbon nanotube networks; Conductivitat elèctrica; Cut-off; cut-off frequency; Density; Dispositius de l’estat sòlid; Electric conductivity; electrical impedance; ELECTRONICS; Física; Física de l’estat sòlid; Impedance; Impedance (Electricity); Impedance measurement; Impedància (Electricitat); Nanotubes; Nanotubs; Networks; Reflectometry; Single wall carbon nanotubes; Slopes; THIN-FILMS; Àrees temàtiques de la UPC
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.201451233

Transparent and flexible networks with randomly distributed single‐walled carbon nanotubes (SWCNTs) are emerging as novel materials for various applications, particularly as electronic materials. We investigate the frequency‐dependent impedance measurements up to 20 GHz, of single‐walled carbon nanotube networks on transparent and flexible substrates, by using two different techniques: two probe and Corbino reflectometry setups. The thickness and roughness of the thin film of SWCNT are examined by AFM. The impedance measurements show the cut‐off frequency increases with increasing the density of SWCNT. The log–log plot of low frequency impedance as a function of the cut‐off frequency shows the same slope in both measuring techniques. The slope is independent on sample geometries, which is characteristic of a totally disordered system. The cut‐off frequencies observed by the Corbino reflectometry technique are 3 orders of magnitude higher than those observed by two‐probe technique even for the same SWCNTs density network.