Novel high-durability luminescent solar concentrators based on fluoropolymer coatings

Fluorescent polymeric coatings can find interesting applications in the field of solar energy as thin-film luminescent solar concentrators (LSCs). At present, polymers such as polycarbonate (PC) or poly(methyl-methacrylate) (PMMA) are commonly used as dye-doped host matrix materials in LSCs. However, LSC devices based on these polymers still present limited lifetimes resulting from the intrinsic poor photostability of the polymeric carrier. In the attempt to achieve high-durability LSC devices, a series of new crosslinked fluoropolymeric systems is presented in this work as potential alternative host matrix coating materials for LSC applications. The chemical, physical and morphological modifications occurring to the crosslinked fluorinated coatings when subjected to long-term UV-vis light exposure (over 1000 h of accelerated weathering) are found to correlate well with the photovoltaic response over long-term operation of functioning LSC devices. In particular, better operational stability compared to reference PMMA-based devices can be obtained with the new crosslinked fluorinated coatings by appropriate selection of crosslinking agent. In addition, the effect of radical scavengers on LSC device operational stability is also investigated and it is found that in the long-term light exposure regime (>600h) these additives may lead to improvements in LSC device lifetime. The results of this study allow a greater understanding of structure-property relationships in crosslinked fluorinated coatings subjected to long-term weathering and provide useful guidelines for the design of high durability fluorescent coatings for light management and photovoltaics. (C) 2013 Elsevier B.V. All rights reserved.