Aggregation-Induced\nEnhanced Red Emission Graphene\nQuantum Dots for Integrated Fabrication of Luminescent Solar Concentrators

Graphene quantum dots (GQDs) commonly suffer from the\nfluorescence\nproblem of aggregation-caused quenching under high-concentration loading\nor in the solid state, which seriously hinders the application. Here\nwe report a type of GQDs with red aggregation-induced enhanced emission\n(AIEE). It is confirmed that the aggregation state of the AIEE GQDs\nis a J-aggregate. The GQDs/poly(methyl methacrylate) film presented\na photoluminescence quantum yield as high as 60.81%, and the record-high\nperformance of luminescent solar concentrators (LSCs) was achieved.\nThe power conversion efficiency (η<sub><i>PCE</i></sub>) is up to 8.35% and the external optical efficiency (η<sub><i>ext</i></sub>) is ∼8.99% for the GQD-based LSCs\n(45 mW/cm<sup>2</sup>). Even under one sun illumination (100 mW/cm<sup>2</sup>), the corresponding η<sub><i>PCE</i></sub> and η<sub><i>ext</i></sub> values are 3.12% and\n4.52%, respectively. The internal photon efficiency (η<sub><i>int</i></sub>) of an LSC device is about 5.02%. The synthesis\nof AIEE GQDs bridges the research gap in the emission mechanism of\n AIEE in GQDs.