Stable and efficient hybrid Ag-In-S/ZnS@SiO2-carbon quantum dots nanocomposites for white light-emitting diodes

Abstract

• Overcome the aggregation-induced quenching effect of CDs in solid state. • A novel white light-emitting nanocomposite with a core–shell structure has been synthesized. • A UV-pumped WLED with a CRI up to 91 has been fabricated with the nanocomposite. • Controllable blue/yellow PL intensity ratios of the prepared nanocomposite. As a promising energy-saving technique, the eco-friendly and low-cost solid-state white light-emitting diodes (WLEDs) based on quantum dots (QDs) have been widely studied. Herein, a WLED device prepared by core–shell structure nanocomposites based on Ag-In-S/ZnS@SiO 2 quantum dots (AIS@SiO 2 ) and carbon quantum dots (CDs) was successfully constructed. CDs were combined onto the surface of AIS@SiO 2 QDs to synthesize Ag-In-S/ZnS@SiO 2 -Carbon quantum dots (AIS-CDs) nanocomposites with a white-light emission, which successfully overcome the quenching effect of CDs induced by conventional aggregation. The as-prepared AIS-CDs nanocomposites presented high stability and a photoluminescence quantum yield (PLQY) of 35%. Moreover, the corresponding AIS-CDs nanocomposites-based WLEDs demonstrated the color coordinate of (0.32, 0.33), which is comparable to the pure white light (0.33, 0.33); furthermore, the luminous efficiency of the as-prepared WLEDs showed 15.1 lm W −1 . These results reported herein may open up a new avenue for the development of high-performance, low-cost, and environmentally-friendly WLEDs.