Solid-State Carbon Dots-Based White Light-Emitting Diodes With Ultrahigh Color Rendering Index and Good Thermal Stability

Solid-state carbon dots (CDs) are a new kind of color converting material for white light-emitting diodes (white LEDs) because of its good luminesce performance and low toxicity; however, CDs in solid state suffer from aggregation-caused quenching (ACQ); thus, solid-state CDs need to be dispersed into or encapsulated with matrix. Herein, we prepared the CDs in one-pot hydrothermal method and encapsulated the CDs with BaSO4 matrix by electrostatic force guided assemble; the CDs@BaSO4 phosphor is further dispersed into silica gel for white LEDs’ application. The thermal stability of our CDs is significantly improved after BaSO4 warping and further application on white LEDs shows great luminescence property of our CDs@BaSO4 phosphors. The morphology, structure, photo luminescence properties, thermal stability, and photo stability of the phosphor are investigated. The fabricated white LEDs characterize for CIE coordinate at (0.3669, 0.3671), belonging to white gamut, and an ultrahigh color rendering index (CRI) (including three indicators: ${R}_{a}= {95.1}, {R}_{{{9}}}= {88.65}$ , and ${R}_{{{13}}}= {97.9}$ ).