Mo coordination and Thermal Stability of the Mo-Si 3 N 4 Absorbers for Solar Selective Coatings

The study of the chemical stability of solar selective coatings (SSC) for concentrated solar power (CSP) becomes essential for their use at high temperatures. In this paper, the short range order around Mo in Mo-Si 3 N 4 cermets is studied for the first time by X-ray absorption spectroscopy. The information obtained by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) spectroscopies gives new insights of the origin of the optical behavior of the cermets cermets after vacuum and air annealing treatments. The established optical and structural correlation becomes of great importance for the design and optimization of SSC for practical applications.