Scandium nitride (ScN) is a rocksalt-structure semiconductor that has attracted attention for its potential applications in thermoelectric energy conversion devices, as a semiconducting component in epitaxial metal/semiconductor superlattices. ScN nanolayers of 30 nm thickness were deposited on MgO (001) substrate by reactive sputtering. Epitaxial growth of ScN(002) was observed with a mosaicity between grains around the {002} growth axis. Both direct band gaps theoretically predicted were measured at 2.59 eV and 4.25 eV for the energy gaps between the valence band and the conductance band at the X point and the Γ point respectively. Electrical and optical properties were observed to be strongly influenced by the crystalline order and the carrier concentration.

Black aluminium thin films were prepared by direct current (DC) pulsed magnetron sputtering. The N₂ concentration in the Ar–N₂ mixture that was used as the deposition atmosphere was varied from 0 to 10%, and its impact on the film growth and optical properties was studied. A strong change in the film growth process was observed as a function of the N₂ concentration. At a specific N₂ concentration of ∼6%, the Al film growth process favoured the formation of a moth-eye-like antireflective surface. This surface morphology, which was similar to the structure of a cauliflower, is known to trap incident light, resulting in films with a very low reflectivity. A diffuse reflectivity lower than 4% was reached in the ultraviolet-visible-near infrared (UV-VIS-NIR) spectral range that corresponds to a value observed for an ultrahigh absorber. We found that for the preparation of black aluminium, the nitrogen content plays an important role in film formation and the resulting film morphology.