Chemically Sustainable Large Stokes Shift Derivatives for High-Performance Large-Area Transparent Luminescent Solar Concentrators

Luminescent solar concentrators (LSCs) have recently emerged as valuable candidates for the realization of aesthetically pleasing solar windows for near-zero-energy consumption buildings. The growing demand by the building-integrated photovoltaic sector is urging the development of sustainable production methods that minimize the use of polluting organic solvents and hazardous materials, while still enabling industrial-grade LSCs. Here, we introduce a new class of benzothieno-benzothiophene (BTBT) derivatives as highly efficient reabsorption-free emitters for transparent LSCs featuring high stability and a solvent-free chemical access with sustainability factor as low as 21, 10 to 50 times lower than conventional LSC emitters. By embedding our BTBT emitters in optical-grade polymeric waveguides, we produced large-area (40 cm × 40 cm) LSCs with optical power efficiency as high as 3% (corresponding to an optical quantum efficiency of 54%). These results represent an important advancement toward sustainable solar glazing systems for green architecture.The growing demand for building-integrated photovoltaic technologies for near-zero-energy buildings is motivating the scientific community to develop devices that meet the functional, energetic, and aesthetic needs for sustainable architecture. Luminescent solar concentrators (LSCs) are emerging as valuable solutions to realize aesthetically pleasing semitransparent photovoltaic windows capable of converting urban buildings into energy generators. In this work, we report on efficient, transparent LSCs based on a novel class of reabsorption-free derivatives synthesized through a solvent-free route that massively improves the sustainability factor with respect to the state of the art. Optical-grade polymeric LSCs are produced via industrial methods with an optical power efficiency as high as 3% despite their transparency in the visible region. These results represent an important step forward for sustainable solar glazing systems for environmentally friendly architecture. Efficient and aesthetically pleasing solar technologies, such as LSC photovoltaic windows, are becoming essential for the widespread of zero-energy buildings. The more the LSC technology gains appeal, the higher the need becomes for efficient and sustainable materials and production routes. Through a new mechanochemical route, we produce efficient, reabsorption-free LSC emitters with a massively increased sustainability factor. The integration of such derivatives into industrial-grade LSCs leads to an optical efficiency of 3% for large-area devices.