Crosslinking UV-curable polymers with organic dyes for highly stable, multifunctional, light-harvesting luminescent solar concentrators

Abstract

A multifunctional luminescent system characterized by outstanding durability is presented in this work as polymeric matrix for luminescent solar concentrators (LSCs). Such coating was fabricated by embedding a modified perylene-based organic dye in a fluorinated matrix consisting in a blend of photo-curable fluorinated polymers. The coating can easily crosslink when exposed to UV-light. The presence of lateral double bonds in the organic dye molecule enables its co-crosslinking with the acrylate fluorinated matrix. Multifunctionality is granted to the coating by remarkably high water contact angle values, slightly exceeding 120°, which impart easy cleaning properties to the LSC device. Accelerated weathering tests (800 h) showed the outstanding stability of LSCs prepared using the fluorinated matrix co-crosslinked with the modified perylene presented here. These devices retained their initial optical efficiency during the intense weathering test. On the contrary, devices fabricated with the same fluorinated polymers, but incorporating a similar dye with the same chemical structure except for the lateral double bonds enabling co-crosslinking with the polymeric matrix, exhibited a 10% efficiency loss over the testing time. The increased stability can be explained by taking into account the effect of the linkage between the organic dye and the host matrix. The fast and easy preparation process presented in this work represents a scalable approach to remarkably stable and truly multifunctional LSCs.