Preparation of liquid silicon-based carbon dots and application for luminescent solar concentrators

Liquid silicon-based carbon dots (CDs) with a photoluminescence quantum yield (PLQY) of 50% were prepared using N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAMO), citric acid, and n-butylamine as raw materials. Firstly, the optimized characters have been determined, namely, the optimal DAMO, citric acid, and n-butylamine addition amounts of 1 mL, 0.9 g, and 1 mL, a reaction time of 3 h, and a reaction temperature of 160 degrees C. Further research has confirmed that the increase in fluorescence intensity of CDs is mainly due to the introduction of DAMO, in which the two amino groups in DAMO play a major role. In addition, the Si-O-Si group generated by the hydrolysis of siloxane groups is connected to the surface of the CDs and forms a core-shell structure, which modifies the defects on the surface and enhances the fluorescence intensity of the CDs. Finally, luminescent solar concentrators (LSCs) based on liquid silicon-based CDs were assembled by spin coating. The obtained device has a transparency of up to 80% and an optical efficiency of 2.4%. The role of DAMO with both amino and siloxane groups: Amino groups are beneficial for obtaining CDs with strong fluorescence intensity. Siloxane groups help to modify the surface defects of CDs and improve their fluorescence intensity. image