Abstract: Converter device for converting energy from electromagnetic radiation, in particular concentrated solar energy, in electrical power, comprising a thermionic emitter (2) and an absorber (1) of electromagnetic radiation, configured to transform electromagnetic radiation energy to thermal energy, having an outer surface (10) configured to be exposed to electromagnetic radiation and an inner surface integrally coupled to the thermionic emitter (2), the outer surface (10) being provided with a sub-micrometer periodic surface structure, the thermionic emitter (2) being monolithically integrated on said inner surface of the absorber (1), the absorber (1) being made of a material selected from the group comprising or consisting of carbide or aluminium nitride-based ceramic materials, and pyrolitic graphite, the thermionic emitter (2) being made of a material selected from the group comprising or consisting of thin film diamond deposited through chemical vapour deposition (CVD), thin film titanium nitride (TiN) or mol

Abstract: A process is described for forming a silicon carbide coating on nickel-based superalloys by:nitriding the alloy or depositing a titanium nitride film on the alloy by reactive sputtering;vapor-phase chemical deposition of a thin film of titanium nitride;annealing in a nitrogen and hydrogen atmosphere;vapor-phase chemical deposition of a silicon carbon layer.