English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

At present, carbon nanotubes (CNTs) confidently expand the field of their practical application. Unique mechanical, electro-physical properties, high chemical and thermal stability of CNTs make it possible to use them as part of modern vacuum electronic devices. The most widely used cold field emitters are based on CNTs. Similar cathode materials are used in flat panel displays with increased luminescence brightness, cathode tubes, X-ray sources and other devices [1]. Fowler–Nordheim (FN) theory is used to describe emission of electrons from CNTs under the action of a uniform constant electric field. Initially, this theory was developed for metallic flat emitters [2]. Specific features of the CNTs structure lead to the introduction of different correction factors in various modifications of this theory [3]. However, the fundamental position of the FN theory – the tunneling effect is in no way connected with the characteristics of the real structure of CNTs, which is a deterrent theoretical factor with a purposeful improvement of the operational properties of real cathode materials. The electron concentration at the ends of CNTs under field emission was experimentally recorded by electron spectroscopy methods, as the field emission process is accompanied in many cases by luminescence [4]. Thus, a non-controversial theory of electron emission from a CNT should proceed from the existence of a molecular state in which the electron density will be mainly localized at the ends of nanotubes. Papers [5, 6] show that in cylindrical carbon molecules due to in-plane electron conjugation of p-electrons [7] are formed of emission molecular orbitals (EMO) with extreme localization electrons on the ends of open singlewalled CNT (SWCNT) with chirality (n, 0) and (n, n), are formed, as shown in Fig. 1. The resulting EMO are vacant. Despite the fact that the electric field is not taken into account, the study of EMO characteristic and the influence on them factors of real structure CNT are important for qualitative estimating the parameters of field emission of electrons from the SWCNT. CNT exhibit the ability to adsorb various low molecular weight gaseous substances (H2, CO2, etc.) [8]. Adsorption of molecules on the graphene surface of CNTs leads to a change in the nanotubes’ electronic and, consequently, emission characteristics of nanotubes.

Influence of admixture atom chemosorption on properties of p-electron conjugated system of open carbon nanotubes