Tuning the Optical Properties and Conductivity of Bundles in Networks of Single-Walled Carbon Nanotubes

Abstract

The films of single-walled carbon nanotubes (SWCNTs) are a promising material for flexible transparent electrodes, which performance depends not only on the properties of individual nanotubes but also, foremost, on bundling of individual nanotubes. This work investigates the impact of densification on optical and electronic properties of SWCNT bundles and fabricated films. Our ab initio analysis shows that the optimally densified bundles, consisting of a mixture of quasi-metallic and semiconducting SWCNTs, demonstrate quasi-metallic behavior and can be considered as an effective conducting medium. Our density functional theory calculations indicate the band curving and bandgap narrowing with the reduction of the distance between nanotubes inside bundles. Simulation results are consistent with the observed conductivity improvement and shift of the absorption peaks in SWCNT films densified in isopropyl alcohol. Therefore, not only individual nanotubes but also the bundles should be considered as building blocks for high-performance transparent conductive SWCNT-based films.

Flexible Perovskite Light‐Emitting Diodes: Characteristics and Performance

“…Recent research suggests that the densified films of SWCNTs can be considered as networks of bundles made of different type of SWCNTs, which have good conductivity in both (axial and radial) directions. [140] Many of nice reviews are dedicated to the flexible applications of SWCNTs films. [141,142] Here, we point out the possibility to pattern SWCNTs films (by means of conventional optical lithography and plasma etching), which provides the interplay between transparency and conductivity of the films.…”

Approaching Technological Limit for Wet‐Pulling Technique

“…[37] The effects of different solvents, polymers, and interbundle linkers were extensively explored. [30,38] In addition, the produced fibers can be densified [39] by either applying volatile liquids or mechanical forces, which create more intimate contacts between individual elements in a fiber. [40] As a mechanical force, stretching, twisting, drawing, and compressing could be utilized to improve the stacking of individual nanotubes.…”