Electron emission from diamond layer on tungsten wire measured in cylindrical electrode configuration

Negative electron affinity of diamond layers can successfully be used for field electron emission applications. There are many devices, where cold electron emission is needed For example, electron microscope, flat panel displays, cathodes of screens and others may employ the negative electron affinity of diamond. The aim of this work was to prepare diamond layers on wire substrates in order to provide field electron emission with great stability and low threshold voltage. The prepared diamond layers on tungsten wires showed such electron field emission properties. They provided a current density of J=0.4 mA/cm² at 3 V/μm while the turn-on field was about 2 V/μm. The effective work function estimated from the Fowler-Nordheim plot of the I-V curve was Φ=0.05 eV. The surfaces of emitters have been investigated by micro-Raman spectroscopy and optical microscopy.