Solid-state photoluminescent silicone-carbon dots/dendrimer composites for highly efficient luminescent solar concentrators

Luminescent solar concentrators (LSCs) with high performances depend on not only the luminescent materials, but their dispersed polymer matrixes. However, carbon dots (CDs)-based LSCs suffer from aggregation-caused fluorescence quenching with the increased concentration of CDs in polymer matrix. To solve this issue, a novel solid-state photoluminescent (PL) silicone-carbon dots (Si-CDs) composites was synthesized by one-step solvothermal treatment of citric acid, dicyandiamide and 3-aminopropyltriethoxysilane (APTES). The solid-state PL Si-CDs showed yellow-green emission at 525 nm under excitation of UV light. For better dispersion of Si-CDs, two types of silicone dendrimers (denoted as D1 and D2) were designed and synthesized via a transesterification and hydrosilylation reaction method. The structure differences between D1 and D2 are the contents of phenyl and methoxy groups. Remarkably, silicone dendrimers with high loading of Si-CDs (up to 35 wt%) could be obtained owing to their good compatibility. Single-layered LSCs could be prepared easily by directly casting the above mixtures on glass substrates followed by room temperature curing. The external optical efficiency ( η opt ) of 7.58%, 5.38% had been achieved from D1 and D2 based LSCs (25 × 25 × 1 mm), respectively. This work provides a convenient method for preparing highly efficient LSCs, posing great potential in various specific applications.