Influence of microstructured substrate on solar selective absorbing films

Abstract

In this paper, the influence of the substrate on the performance of solar selective absorbing films is considered experimentally. The microporous structures of aluminium foils are fabricated by a two-step anodisation method and TiN_xO_y multilayer films are deposited on untreated aluminium foils, polished aluminium foils and porous aluminium foils respectively. It is found that the solar selective absorbing performance of multilayer films is dependent on the microstructure of substrate surfaces. The films on the substrate after polishing treatment have the lowest absorptance. The surface oxide layer, which is a porous structured layer on aluminium foil, can result in the increase of the absorptance α and the emittance ϵ of the solar films. The reflectance of the film deposited on the microstructured substrate is lower in general. Moreover, the thickness of the surface oxide layer can be moderated to decrease thermal emittance of the solar selective absorbing films.

Keywords:

• Solar
• Micropore
• Absorptance
• Emittance
• Reflectance

This work is supported by Jiangsu ‘333’ Project and Opening Foundation of Jiangsu Key Laboratory for Solar Cell Materials and Technology (201103).