Environmentally friendly luminescent solar concentrators based on optically efficient and stable green fluorescent protein

Luminescent solar concentrators (LSCs) are a solution to overcome the mismatch between solar cells absorption and the solar spectrum, facilitating the integration of photovoltaic (PV) devices into the urban environment, since they can be incorporated in building facades and windows. Challenges include the search for environmentally friendly materials with chemical and optical stability. To overcome these drawbacks, in this work, the enhanced Green Fluorescent Protein (eGFP) was efficiently applied as an optically-active center. eGFP absorbs in the UV/visible spectra and convert it into green emission with a maximum absolute quantum yield of 0.50. Here, we report the use of eGFP to fabricate planar LSCs in liquid (aqueous solution) and solid state (incorporated in organic-inorganic hybrids), which were coupled to commercial Si-based PV cells yielding power conversion efficiency (PCE) values up to 0.35%, which is 30% higher than those reported so far. These results are presented as higher than the figures of merit for natural-based fluorescent proteins in aqueous medium, with the advantage of presenting enhanced photostability when stored at ambient conditions. Those are relevant features, uncommon in organic-based materials, that significantly contribute to the potential of natural-based molecules in the development of LSCs as reliable, sustainable and competitive energy systems.