Improving the visible transmittance of low-e titanium nitride based coatings for solar thermal applications

► We study three different strategies in order to improve the optical properties of TiN layers as low-e coatings. ► We deposit TiN, TiAlN coatings and TiO2/TiN/TiO2 multilayers by reactive magnetron sputtering. ► Post deposition annealing treatments improve in a 10% the TiN visible transmittance while keeping constant the emittance. ► Multilayers structures present the best results by improving a 30% the TiN visible transmittance without degrading the emittance.