Effect of O2+, H2++ O2+, and N2++ O2+ ion-beam irradiation on the field emission properties of carbon nanotubes

Abstract

The effect of O2+, H2++ O2+, and N2++ O2+ ion-beam irradiation of carbon nanotubes (CNTs) films on the chemical and electronic properties of the material is reported. The CNTs were grown by the chemical vapor deposition technique (CVD) on silicon TiN coated substrates previously decorated with Ni particles. The Ni decoration and TiN coating were successively deposited by ion-beam assisted deposition (IBAD) and afterwards the nanotubes were grown. The whole deposition procedure was performed in situ as well as the study of the effect of ion-beam irradiation on the CNTs by x-ray photoelectron spectroscopy (XPS). Raman scattering, field-effect emission gun scanning electron microscopy (FEG-SEM), and field emission (FE) measurements were performed ex situ. The experimental data show that: (a) the presence of either H2+ or N2+ ions in the irradiation beam determines the oxygen concentration remaining in the samples as well as the studied structural characteristics; (b) due to the experimental conditions used in the study, no morphological changes have been observed after irradiation of the CNTs; (c) the FE experiments indicate that the electron emission from the CNTs follows the Fowler-Nordheim model, and it is dependent on the oxygen concentration remaining in the samples; and (d) in association with FE results, the XPS data suggest that the formation of terminal quinone groups decreases the CNTs work function of the material.

Surface Engineering of Multi-Walled Carbon Nanotubes via Ion-Beam Doping: Pyridinic and Pyrrolic Nitrogen Defect Formation

“…Additionally, the multi-step nature of the post-treatment procedure contributes to the elevated production costs of N-CNTs. To address these challenges, ion and plasma treatment methods are promising, offering precise control over nitrogen doping parameters [39][40][41][42][43][44][45]. Studies have demonstrated that plasma treatment, influenced by parameters like plasma power, pressure, and exposure time, can lead to N-CNTs with varying nitrogen content (up to 8-20 at.%) embedded into their wall structure [43,44].…”

Computational Modelling of Surface Modified Carbon Nanotube for Low Temperature Fuel Cell

“…The extent of this defect formation is well understood by a parameter known as the displacement per atom (dpa) which is a very useful tool for understanding the extent of surface modification of a carbon nanotube via ion irradiation. This ion irradiation technique is particularly significant as here the defects are created in a controlled fashion [8,9]. Ion irradiation leads to some defects in MWCNT, alters the CNT composition due to ion incorporation.…”

Self-organized nickel nanoparticles on nanostructured silicon substrate intermediated by a titanium oxynitride (TiNxOy) interface

“…An alternative approach adopted in the present contribution, involves the use of titanium oxynitride (TiN x O y ) thin films which, additionally, presents low residual stress, good thermal-electrical conductivity, and is compatible with the fabrication of devices. 12 Regarding the strain, it is well-known that ions arriving at the substrate with enough energy (>100 eV) are implanted giving rise to stress. [13][14][15][16][17] A typical example involves xenon atoms that, because of their large sizes, occupy smaller places inside the silicon lattice inducing stress in the network outwards and parallel to the silicon surface by the knock-on process.…”