One-step microwave synthesis of high-efficiency solid-state luminescent carbon dots with aggregation-induced emission

Carbon dots (CDs) are biophilic quantum dots with excellent luminescent properties, however, the aggregation-caused quenching (ACQ) effect is a serious limitation for their application in solid-state devices. In this manuscript, a solid-state luminescent blue CDs (B-CDs) with a high fluorescence quantum yield of 52% was prepared by a microwave-assisted method. The B-CDs showed weak fluorescence and with a photoluminescence fluorescence quantum yield (PLQY) of only 0.63% in aqueous solution, but exhibited an aggregation-induced emission in the solid state. The AIE phenomenon of B-CDs was shown to result from the inhibition of surface chromophore motion during aggregation by characterizing the PL intensity under different ratios of DCM (poor solvent). Furthermore, the fluorescence kinetic mechanism associated with the B-CDs was investigated by the time-resolved PL. Finally, a blue LED with CIE coordinates of (0.15, 18) was fabricated using B-CDs as the phosphor, showing a promising potential application in solid-state optoelectronic devices.