Sustainable Liquid Luminescent Solar Concentrators

Abstract Luminescent solar concentrators (LSCs) are photovoltaic (PV) complementary devices to overcome the mismatch between the Si‐based PV cells, response and the solar spectrum, allowing PV urban integration. Challenges for the luminescent layer include the use of abundant and sustainable natural organic molecules. Here, LSCs composed of a glass container and based on bundles of cylindrical hollow‐core plastic optical fibers filled with aqueous solutions of R‐phycoerythrin (R‐PE), extracted from Gracilaria sp. algae are presented. The R‐PE solutions absorb in the UV/visible spectral range (300–550 nm) and convert this radiation into red‐emission (550–700 nm) with a maximum absolute quantum yield of ≈0.39. In this work, LSCs with distinct geometries are reported, in which the R‐PE emission yields optical conversion efficiency values up to ≈6.88% and ≈4.74% for a planar device and for a bundle of cylindrical LSCs, respectively, which are the largest values known for liquid‐based LCSs using sustainable emitting centres. Moreover, the coupling of the LSCs to commercial Si‐based PV devices yields power conversion efficiency values of ≈0.27% (planar) and ≈23.03 × 10⁻³%, (bundle). These values illustrate the potential of this approach for the development of natural‐based LSCs meeting the requirements of reliable, sustainable, and competitive energy systems.