Experimental investigation of field electron emission from uncoated and coated graphite fiber tips

Abstract This study investigates the field emission characteristics of coated and uncoated graphite fiber tips under high vacuum conditions in the pressure range of 10 –6 Pa. A 2 M Sodium hydroxide (NaOH) solution was used in the electrochemical etching procedure to produce an uncoated etched graphite fiber emitter with a diameter of 436.5 nm. An epoxy coating 2301 dielectric material with a thickness of 61 ± 1 nm was used to coat the fiber tip. Field-emitter emission micrographs, current stability, and current-voltage ( I-V ) characteristics were recorded. Murphy’s Good plots were used to examine and analyse the I-V characteristics. An orthodoxy test was performed to evaluate the Murphy Good plots. In the reported results, at low applied voltages, the uncoated graphite fiber emitter passed orthodoxy tests, and generated a steady current with 0.03 µA uncertainty. However, the coated graphite fiber emitter showed an increase in the applied voltage and threshold voltages but had no impact on the sample emission characteristics.