Bright and multicolor emissive carbon dots/organosilicon composite for highly efficient tandem luminescent solar concentrators

Carbon dots (CDs) hold great promise for effective alternatives to traditional luminescent materials in the field of luminescent solar concentrators (LSCs) due to their low cost, eco-friendly and stability. How to improve the performance of CDs based LSCs is the research focus at present. Herein, a novel CDs/organosilicon composite (SiCDs) with tunable solid-state fluorescence and photoluminescence quantum yield from 21% to 56% is reported to cope with the limitation of aggregation-caused quenching of CDs on the performance improvement of LSCs. The emission redshift mechanism of SiCDs have been explored in detail. Furthermore, the UV absorption of SiCDs is in wide range and gradual increase in intensity as the emission red shifted from blue to orange. The SiCDs are further designed to construct a series of transparent single-layer and tandem LSCs with polydimethylsiloxane as waveguide material, and the tandem LSC based on blue and yellow emission SiCDs achieve a finally external optical efficiency of 7.10%.