Environmentally friendly luminescent solar concentrators based on an optically efficient and stable green fluorescent protein†
Luminescent solar concentrators (LSCs) are a solution to overcome the mismatch between solar cell absorption and the solar spectrum, facilitating the integration of photovoltaic (PV) devices into the urban environment, since they can be incorporated in building façades and windows. Challenges include the search for environmentally friendly materials with chemical and optical stabilities. The enhanced green fluorescent protein (eGFP) was efficiently applied as an optically active center. eGFP absorbs in the UV/visible range and converts 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 the liquid (aqueous solution) and solid state (incorporated in organic–inorganic hybrids), which were coupled to commercial Si-based PV cells yielding power conversion efficiency values of up to ∼0.35%. These results are higher than the figures of merit for naturally-based fluorescent proteins in aqueous media, with the advantage of presenting enhanced photostability when stored under ambient conditions. These are relevant features, uncommon in organic-based materials, which significantly contribute to the potential of naturally-based molecules in the development of LSCs as reliable, sustainable and competitive energy systems.