Effect of increased crystallinity of single-walled carbon nanotubes used as field emitters on their electrical properties

Abstract

Single-walled carbon nanotubes (SWCNTs) synthesized by arc discharge are expected to exhibit good field emission (FE) properties at a low driving voltage. We used a coating containing homogeneously dispersed highly crystalline SWCNTs produced by a high-temperature annealing process to fabricate an FE device by a wet-coating process at a low cost. Using the coating, we succeeded in reducing the power consumption of field emitters for planar lighting devices. SWCNTs synthesized by arc discharge have crystal defects in the carbon network, which are considered to induce inelastic electron tunneling that deteriorates the electrical conductivity of the SWCNTs. In this study, the blocking of the transport of electrons in SWCNTs with crystal defects is simulated using an inelastic electron tunneling model. We succeeded in clarifying the mechanism underlying the electrical conductivity of SWCNTs by controlling their crystallinity. In addition, it was confirmed that field emitters using highly crystalline SWCNTs can lead to new applications operating with low power consumption and new devices that may change our daily lives in the future.

Scalable Approach To Construct Free-Standing and Flexible Carbon Networks for Lithium–Sulfur Battery

“…Carbon nanomaterials, such as fullerene, carbon nanotubes (CNTs), and graphene, exhibit wide applications in materials science, , new energy, and biological and environmental technologies due to their unique morphological and electronic structures. Except for the research on nanoscale devices (e.g., field emitter, molecular sensor, and graphene barrister), more and more efforts have been devoted to constructing macrosized two- or three-dimensional films/membranes with different hierarchical structures satisfying industrial utilizations in the fields of water treatment, gas separation, and energy storage devices . Therefore, it would be very significant to develop one feasible strategy to reconstruct these single nanounits into a hierarchical one with more intriguing performances.…”

Effect of Crystallinity on the Field Emission Characteristics of Carbon Nanotube Grown on W-Co Bimetallic Catalyst

“…The adhesion of amorphous carbon on the CNT surface leads to the decrease in the σ-π hybrid bond intensity, which makes the Fermi energy level move upward, resulting in a slight increase in work function [28]. The presence of defects in the CNT lead to inelastic electron tunneling, resulting in the energy loss of emitted electrons, thus exhibiting higher work function [29]. To determine separately the change of work function and field enhancement factor among the five samples, a Seppen-Katamuki (SK) chart was adopted to analyze the FN data.…”

“…As the second reason, the high crystallinity of CNT decreases the scattering of electrons when electron flow goes through the tube, thus resulting a small body resistance and less Joule heat generation [29]. Consequently, the voltage drop on the tube is small, which results in a low turn-on field.…”

Low-power-consumption flat-panel light-emitting device driven by field-emission electron source using high-crystallinity single-walled carbon nanotubes

“…The mobility of electrons, which flow inside nanotubes as pseudoballistic electrons, is significantly improved owing to the reduction in crystal defects within the nanotubes because of the high crystallization. 37) 2.2 Evaluation of luminance characteristics of longafterglow fluorescent material used for triode-structure light-emitting devices FE-activated thin films are important components in electron emission sources. Such thin films were used to fabricate a vacuum tube lamp (Y.A.C.)…”