Lignin-Derived Carbon Dots with Triple Emission Peaks for Lighting Modules and Backlight Display

White light-emitting diodes (WLEDs) have attracted alot of attentionfor their small size, low energy consumption, and fast response time.However, developing a green material to replace the non-renewablerare earths in the preparation of WLEDs remains a big challenge atpresent. Here, biomass carbon dots (CDs) are compounded with polyvinylalcohol (PVA) to obtain a solid fluorescent material that can replacerare earth phosphors for the preparation of WLEDs. LignosulfonateCDs (L-CDs) prepared using sodium lignosulfonate as the carbon sourceshow a unique characteristic of triple emission peaks under ultravioletexcitation. L-CDs@PVA prepared by combining CDs with PVA can overcomethe aggregation-induced quenching (AIQ) effect and exhibit white fluorescenceunder ultraviolet (UV) due to supramolecular cross-linking. Chromaticitycoordinate (CIE) analysis shows that the light coordinates emittedby L-CDs@PVA (0.297, 0.318) are very close to the standard white lightcoordinates (0.330, 0.330). The WLEDs were prepared by using L-CDs@PVAas a white light conversion layer, and finally, the lighting modulesand backlight modules were assembled in surface mount technology forillumination and display. The cross-combination of optical materialsand bioenergy has a positive effect on sustainable development.