Electron Emission Properties of Self-Assembling Nanodiamond‒Polymer Nanocomposite Coatings

Abstract

The formation of thin-film coatings from detonation nanodiamond (DND) suspensions on atomically ordered conducting Ni–W substrates by self-assembly in an evaporating aqueous solution using the spin coating technique has been investigated. It is shown that, in the absence of a polymer matrix, the DND distribution over the substrate is nonuniform and the adhesion to the substrate is weak, which prevents obtaining a uniform and stable emission current. The use of DND–water-soluble polymer (chitosan and carrageenan polysaccharides, polyacrylic acid, and sulfonated polyaniline (SPANI)) coatings makes it possible to enhance the film adhesion to the substrate and provide a disaggregated state of nanocrystallites. The DND–SPANI coatings have demonstrated the best emission characteristics. Based on the analysis of the emission characteristics, a new model of emission center in the DND–polymer–substrate system has been proposed.