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Vertically aligned carbon nanotubes having the advanced atomic configuration, structural properties, and electronic conductivity, which makes the CNTs as an eminent candidate for the electron field emission. In the present work, we have altered the morphology of the vertically aligned - CNT field emitters for improving the electron field emission parameters and temporal stability. The structural tuning and alteration of CNT field emitters was performed in the electron cyclotron resonance based chemical vapor deposition system via generating a dense resonating plasma of $${\text{N}\text{H}}_{3}$$ gas. The as-synthesized pristine and resonating plasma treated VA-CNT field emitters were characterized by field emission scanning electron microscope for study the morphology, and Raman spectroscopy for the analysis of quality and structural defects. The horn type protrusions were formed after resonating plasma treatment. The electron field emission properties were drastically influenced by the time-based resonating plasma treatment. In terms of the reduction in the turn-on $$\left({E}_{to}\right)$$ and threshold $$\left({E}_{th}\right)$$ electric fields, improvement in the emission current density $$\left(J\right)$$ , increment in the conventional characteristics field enhancement factor $$\left(\gamma \right)$$ , and excellent temporal emission stability due to the incorporation of nitrogen species in the graphitic sheet of nanotubes, reduction in the screening effect, edge effect enhanced, and formation of defects in the graphitic sheet of VA-CNT. The calculated scaled barrier field values belong in the acceptable range and hence, orthodox emission hypothesis test qualified.

A novel one-dimensional carbon material Known as carbon nanotubes (CNTs), having their high aspects ratio and as well as advance electrical properties which make them best candidate for cathode field emitters. In this work, we have introduced the easy and cost-effective approach to improving the CNT field emitters emission properties. Here we have modified the surface of CNT field emitter via decorating with silver nanoparticles (Ag NPs). Attachment of Ag NPs on CNT surface via thermal evaporation technique. The as-prepared samples of pristine CNTs and decorated CNTs with Ag NPs were characterized by the scanning electron microscope for morphology analysis, quality and qualitative analysis done by Raman spectroscopy. Here we have applied the Fowler Nordheim hypothesis for the analysis of electron field emission of as-prepared cathode field emitters. The turn-on ( E to ) and threshold ( E th ) field reduced after CNT field emitters coated with Ag NPs. The field enhancement factor ( β ) and emission current density ( J ) enhanced after coating. Ag NPs decorated/coated CNT field emitters can be utilized in field emission device applications.

Multi-walled carbon nanotubes (MWCNTs) were grown on Silicon (Si) substrate by using low-pressure chemical vapor deposition (LPCVD) technique where iron (Fe) and silver (Ag) colloidal solution act as a catalyst were prepared by chemical route. The as-prepared solutions in varied concentrations were deposited on a Si substrate using a spin coating process at 700[Formula: see text]rpm. The purpose of Fe in composite catalysts is to have high carbon solubility and diffusion rate, and Ag utilization can change catalyst activity temperature and enhance carbon yields. In this work, we demonstrate the growth of carbon nanotubes (CNTs) on different catalyst concentrations ([Formula: see text]Fe/[Formula: see text]Ag), ([Formula: see text]Fe/[Formula: see text]Ag), ([Formula: see text]Fe/[Formula: see text]Ag) and ([Formula: see text]Fe/[Formula: see text]Ag) catalytic films. Field Emission Scanning Electron Microscopy (FESEM) was used to image the morphologies of various catalyst concentrations MWCNTs. The natures of the synthesized CNTs were determined using Raman spectroscopy and it was revealed that as-prepared CNTs are MWCNTs due to the absence of radial breathing mode (RBM). Raman spectroscopy demonstrated the lower ID/IG ratio (Ratio of the intensity of D-Raman peak and G-Raman peak) of ([Formula: see text]Fe/[Formula: see text]Ag) MWCNTs. The ID/IG ratio for ([Formula: see text]Fe/[Formula: see text]Ag) catalyzed MWCNTs was 0.76, while the ID/IG ratio for ([Formula: see text]Fe/[Formula: see text]Ag) catalyzed MWCNTs was 0.89. The ([Formula: see text]Fe/[Formula: see text]Ag) catalyzed MWCNTs were found to be more defective as compared to other. Electron Emission from ([Formula: see text]Fe/[Formula: see text]Ag) catalyzed MWCNTs were much stronger than from other samples, as demonstrated by Field Emission measurement using diode configuration. The turn-on field for ([Formula: see text]Fe/[Formula: see text]Ag) catalyzed MWCNTs was (0.92 V/[Formula: see text]m) which is slightly lower than that of ([Formula: see text]Fe/[Formula: see text]Ag) catalyzed MWCNTs (1.83 V/[Formula: see text]m), indicating superior enhancement.