Field Emission Characteristics of Carbon Black Particles and Various Types of Carbon Nanotubes Using Glass Tubes

Abstract

Abstract: Carbon-based nanomaterials have gained considerable attention in recent decades owing to their exceptional structural and material characteristics, such as high thermal and electrical conductivity, chemical stability, and high aspect ratio. These remarkable properties make carbon-based nanomaterials highly desirable for various scientific and industrial applications. In this research, the field electron emission (FEE) properties of different materials were investigated using current-voltage (I-V) characteristics and the well-known Fowler-Nordheim (FN) plots. Specifically, four types of carbon-based nanomaterials were examined: single-walled carbon nanotubes (SWCNTs) synthesized through a high-pressure carbon monoxide process involving Fe particles, multi-walled carbon nanotubes (MWCNTs) with a carbon purity of 90% known as NanoclyTM NC 7000, carbon nanotube fibers (CNTFs) denoted as III PR-1, and carbon black (CB) referred to as Vulcan XC72. Field emission tips, also known as emitters, were fabricated using a glass-drawing technique, with the carbon material inserted until it protruded from the broken end. These emitters were then characterized using field emission microscopes (FEM) under ultra-high vacuum (UHV) conditions, with a cathode-to-screen (anode) separation of approximately 10 mm. The results obtained from the CB material exhibited satisfactory agreement with the linearity of the FN plots, while the other materials showed this agreement primarily at low applied voltages. The emission images appeared as a single-spot pattern at low voltages for SWCNTs and CNTFs, whereas CB and MWCNTs exhibited this characteristic pattern at higher voltages.