Large-scale nanostructured low-temperature solar selective absorber

• Published in: Optics letters Vol. 42; no. 10; p. 1891
• Main Authors: Chi, Kequn, Yang, Liu, Liu, Zhaolang, Gao, PingQi, Ye, Jichun, He, Sailing
• Format: Journal Article
• Language: English
• Published: United States 15.05.2017
• ISSN: 1539-4794
• DOI: 10.1364/OL.42.001891

A large-scale nanostructured low-temperature solar selective absorber is demonstrated experimentally. It consists of a silicon dioxide thin film coating on a rough refractory tantalum substrate, fabricated based simply on self-assembled, closely packed polystyrene nanospheres. Because of the strong light harvesting of the surface nanopatterns and constructive interference within the top silicon dioxide coating, our absorber has a much higher solar absorption (0.84) than its planar counterpart (0.78). Though its absorption is lower than that of commercial black paint with ultra-broad absorption, the greatly suppressed absorption/emission in the long range still enables a superior heat accumulation. The working temperature is as high as 196.3°C under 7-sun solar illumination in ambient conditions-much higher than those achieved by the two comparables.