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Abstract: A new solar selective absorbing coating of NbTiON/SiON was prepared on Cu substrate using a reactive magnetron sputtering method. The new coating exhibits a high absorptance (α) of 0.95 and a low emittance (ε) of 0.07, and the thickness of NbTiON and SiON layers was optimized to achieve high solar selectivity. The spectral properties (α/ε) of the coating on Cu substrate are stable (0.94/0.08) even after heat-treatment at 500°C in vacuum for 40h, but decreased at 600°C. If the substrate is replaced by stainless steel (SS), the coating exhibits better stability, which indicates its potential applications in intermediate temperate solar absorber. [Copyright &y& Elsevier]

For the applications in solar thermal power, the preparation and optimization of an Al/NbMoN/NbMoON/SiO 2 multilayer solar selective absorbing coating are carried out by combining experiments with optical simulation. A series of NbMoN and NbMoON single layers are deposited by magnetron reactive sputtering method with different N 2 /O 2 gas flowing rates. And then their optical constants are obtained by fitting their reflection (R) and transmission (T) spectra in the wavelength range of 300–2500 nm using SCOUT software. These optical constants are used to design the Al/NbMoN/NbMoON/SiO 2 solar selective absorbing coating so as to get the ideal spectral selectivity, i.e. high α / ε ratio. According to the optical design of the coating structure, we prepared the all-layer coating, and the thickness of each layer was optimized until the best spectral selective properties are obtained. The experimental reflectance spectrum fits very well with the simulated result. The optimized solar absorbing coating deposited on stainless steel substrate exhibited high absorptance ( α =0.948) and low emittance ( ε =0.050) at 80 °C. It offers a good method to quickly reach the ideal spectral selectivity through optical simulation. The thermal stability of the coating is evaluated, and it exhibits a good thermal stability in vacuum at 400 °C. [ABSTRACT FROM AUTHOR]

Abstract: Mo–Al2O3 solar selective absorbing coating was deposited on stainless steel substrate by magnetron sputtering. The evaluation of high temperature stability indicates that the degradation of the optical properties is due to the diffusion and oxidation of single metal Mo in the ceramic Al2O3. Mo diffuses easily in Al2O3 layer and the interface between the double Mo–Al2O3 layers when aging temperature is above 400°C, which was observed by SEM and AES with etching depth. The thermal stability was improved significantly when a denser Mo–Al2O3 layer was obtained by optimizing the deposition parameters. [Copyright &y& Elsevier]