Enhanced absorptance of surface-textured tungsten thin film for solar absorber

Abstract

To improve the absorptance and emittance, single layer surface-textured metal tungsten (W) thin film is fabricated by magnetron sputtering through the adjustment of deposition parameters. The surface-textured single layer W thin film exhibits a high absorptance of 0.74 and a low emittance of 0.05 due to the high aspect ratio subwavelength structures. Based on the surface-textured W coating, the SS/W/Al₂O₃ tandem spectrally selective solar absorber is designed and fabricated. Solar absorptance of 0.90 can be obtained with thermal emittance of 0.06. The surface-textured W and film structural of SS/W/Al₂O₃ tandem coating may open an new avenue for the spectrally selective solar absorber coating.

Keywords:

• Spectrally selective solar absorber
• Surface textured
• Magnetron sputtering
• Optical properties

Acknowledgements

This work was financially supported by NSFC (51402315), the Western Light Talents Training Program of CAS and the Science and Technology Support Program of Gansu Province (Grant 1304GKCA025).