Aggregation-Induced Enhanced Red Emission Graphene Quantum Dots for Integrated Fabrication of Luminescent Solar Concentrators.

Graphene quantum dots (GQDs) commonly suffer from the fluorescence problem of aggregation-caused quenching under high-concentration loading or in the solid state, which seriously hinders the application. Here we report a type of GQDs with red aggregation-induced enhanced emission (AIEE). It is confirmed that the aggregation state of the AIEE GQDs is a J-aggregate. The GQDs/poly(methyl methacrylate) film presented a photoluminescence quantum yield as high as 60.81%, and the record-high performance of luminescent solar concentrators (LSCs) was achieved. The power conversion efficiency (η PCE ) is up to 8.35% and the external optical efficiency (η ext ) is ∼8.99% for the GQD-based LSCs (45 mW/cm 2 ). Even under one sun illumination (100 mW/cm 2 ), the corresponding η PCE and η ext values are 3.12% and 4.52%, respectively. The internal photon efficiency (η int ) of an LSC device is about 5.02%. The synthesis of AIEE GQDs bridges the research gap in the emission mechanism of AIEE in GQDs.