A high-temperature stable spectrally-selective solar absorber based on cermet of titanium nitride in SiO2 deposited on lanthanum aluminate

•The nonmetal filler (TiN) is included into the SiO2 host to achieve the sunlight absorption.•The substrate effect on the thermal stability is investigated.•A stable solar absorptance of 94% with a super long-term thermal stability up to 700 °C is achieved in the spectrally-selective solar absorber deposited on lanthanum aluminate substrate.

Spectrally-selective solar absorber is required to be thermally stable at high operational temperature. However the currently available absorbers aren't stable beyond 700 °C. Here we explore a new absorber with cermet of TiN in SiO2 on LaAlO3 substrate that can be used for long term at 700 °C. The optimized cermets contain TiN with volume fraction of 60% and 65% as sun-light absorption media, SiO2 as anti-reflection coating (ARC), and tungsten (W) as infrared (IR) reflection layer. The absorbers demonstrate an absorptance higher than ~95% before annealing and ~94% after annealing at 700 °C, which will be useful for especially concentrated solar applications.

Graphical abstractThe novel cermet with nonmetal inclusion in SiO2 host is successfully introduced in the cermet-based spectrally-selective solar absorber, which demonstrates a super long-term thermal stability up to 700 °C with a stable solar absorptance of 94%.Figure optionsDownload full-size imageDownload high-quality image (167 K)Download as PowerPoint slide