Effect of Light Scattering in Transparent Wood Luminescent Solar Concentrators for Improved Performance and Photostability

Transparent wood (TW) is a promising candidate for sustainable building-integrated photovoltaics, yet its complex anisotropic light transport behavior remains poorly understood. This work clarifies the roles of scattering and light guiding in TW and provides the necessary framework for sustainable, efficient wood-based luminescent solar concentrators (LSCs). We report on a Rhodamine 6G-functionalized TW-LSC whose cellulose scaffold has a protective effect on the fluorophore, enhancing its photostability. We challenge the prevailing assumption that longitudinal guided emission dominates performance by resolving the interplay between anisotropic scattering and light guidance. This work also demonstrates that for small device dimensions, light is mainly directed perpendicular to the fiber axis as transverse scattering outcompetes longitudinal waveguiding of emission and yields a power conversion efficiency of 1.3%. For longer light path lengths, guided emission dominates over scattering. Beyond optical performance, a critical life cycle assessment estimated a global warming potential of 17 kg CO2 equiv·kg-1 TW, highlighting the burdens posed by the fossil-based matrix in TW.