Single-Crystalline ZnO/Graphene Quantum Dots Phosphors-Converted White Light-Emitting Diodes

In this letter, phosphor-converted white light-emitting diodes (LEDs) were analyzed based on the single-crystalline (SC) ZnO film/graphene quantum dots (GQDs) as phosphors with ultraviolet (UV) excitation. Color rendering index (CRI) and correlated color temperature (CCT) are found to be improved with injection current. The luminous efficiency of 245 lm/W at 260 mA has been achieved with 98 CRI and 5064 K CCT. The results show that the UV excited SC ZnO coated with GQDs white LEDs are more optically compatible for solid-state lighting, compared to the conventional blue chip-excited yellow phosphors LEDs.