A Comparative Study of Field Emission From Semiconducting and Metallic Single‐Walled Carbon Nanotube Planar Emitters

Abstract

Field electron emission from thin films composed of solely metallic or semiconducting single-walled carbon nanotubes is investigated using a scanning tip anode technique. Metallic and semiconducting nanotubes are separated by aqueous two-phase extraction. Local field emission centers observed on nanotube films of both types showed non-linear FowlerNordheim (FN) plots bent downwards. The curving of FN plots is much stronger for semiconducting nanotubes which is explained by their higher electrical resistance and stronger field penetration effect compared to metallic nanotubes. Particular nanotubes of both types revealed oscillations in current-voltage characteristics. The periodic oscillations indicated that the field emission current is modulated either by resonant tunnelling from confinement states in nano-objects formed by adsorbates or by the Coulomb blockade effect that can occur for emission from short carbon nanotubes.

Field Emission Cathodes to Form an Electron Beam Prepared from Carbon Nanotube Suspensions

“…The research stopped because of the emergence of the OLED; the latest news about commercial field-emission displays (FEDs) comes from 2009 [68] and 2010 [69]. Despite the stoppage, CNTs and their composites continue to be researched in terms of cold emission, which is unveiling new phenomena and mechanism models [70][71][72][73] from doped CNTs [74], CNT fibers [75,76] and rods [77], or triangular spatial film [78].…”

“…Fillers, then prevalent as binders, fill the empty spaces between the CNTs and the CNTs and the substrate. This improves the adhesion [1,115] necessary to perform mechanical post-treatment, ensures the recovery of the connection of CNTs which broke down due to Joule heating [71], but also enables us to avoid the arcing during emission [150]. It improves the field enhancement effects as a consequence of the protruding CNTs [138] or thermal stability, where fillers may play the role of oxidation-inhibiting compounds similar to the boron-or phosphorous-related compounds, as it has been presented by Floweri et al [73], where the addition of Ni prevailed the degradation of the field emission.…”

Purification of Single‐Walled Carbon Nanotubes Using Acid Treatment and Magnetic Separation

“…The shape of SWCNT's absorption spectra is dominated by the background π-plasmon resonance at 260 nm ( Figure 2b). [24] In the energy interval 600-2500 nm, the spectra of inSW and SW_HCl samples demonstrate three broad bands caused by optical transitions between the principal mirror van Hove singularities in the valence and conduction bands for metallic (M 11 ) and semiconducting SWCNTs (S 11 and S 22 ). [25] The treatments with oxidative acids cause vanishing of the most prominent peak S 11 and suppresses of peak S 22 .…”

Nanocarbon Photonics and Optoelectronics

“…The papers presented in this Special Issue demonstrate also characterization of electrochemical, electromagnetic, and thermal properties of graphenic carbon structures. In the work of Kleshch et al it is shown that investigation of electron field emission may be used to reveal particular features of metallic and semiconducting carbon nanotubes . Additionally to that, photo‐ and cathodo‐luminescence investigations are shown to have a high efficiency in characterizing wide band gap diamond materials as it is demonstrated in the paper of Malykhin et al…”

“…The productive discussions during the meeting (which has been held on 19–24 March 2017) were provided by perfect organization and nice natural environment, including ski slopes, at Krasnaya Polyana resort (Sochi, Russia). The contributions (in total an amount of 30) of this Special Issue are covering research work related to production, characterization and application of the nanocarbon materials which include diamonds, carbon nanotubes, graphene other types of nanocarbon materials, and their composites . Traditionally for the NPO Workshop series there is also some portion of reports devoted to non‐carbon materials demonstrating properties and phenomena analogous to those observed for nanocarbons.…”