“…Interest in carbon-nitrogen compounds gained impetus after works in the 1980s [7,8], which predicted excellent mechanical properties for carbon nitrides designed as h-C 3 N 4 , with a bulk modulus even greater than for diamond. Indeed, carbon nitride films produced with vapor phase synthesis methods showed low friction and high wear resistance [9][10][11][12][13][14], and proved to be excellent barriers for water and oxygen permeation, analogously to silicon nitride [15]. Nevertheless, carbon nitride films have not been explored as barrier coatings for materials or electronic devices, in which the permeation of water and/or oxygen appears as an obstacle for commercial application.…”