Self-Assembling Polymer–Nanodiamond Composite Coatings for Vacuum Cathodes

The principles of the formation of detonation nanodiamond–polymer thin-film nanocomposites which are promising materials for highly cost-effective field electron vacuum cathodes are studied for the first time. The coatings are deposited onto oriented substrates (Ni, Si) in the processes of self-assembly from an evaporating aqueous solution by the spin-coating technology. Field electron emission studies show that the threshold voltage exceeds values typical for nanocarbon structures by more than ten times. At the same time, it is nearly ten times lower than the work function in macroscopic diamond or graphite. An improvement in the stability of the emission properties of the coating in the presence of polymers in comparison with the deposition of films from a solution of nanodiamond crystallites without polymers is established. © 2018, Pleiades Publishing, Ltd.