Solution-Processed Near Unit Carbon Dots-Based Deep-Blue Electroluminescent Light-Emitting Diodes with External Quantum Efficiency over 10%

Deep-blue electroluminescent light-emitting diodes (ELEDs) are crucial for various applications, including solid-state lighting, high-density information storage, and vibrant displays. Currently, the development of conventional deep-blue ELEDs is predominantly based on multilayer evaporation structures. Despite significant technological progress, the fabrication of electroluminescent devices via low-cost solution processing has still not fully been realized. Given that, a novel approach for their development based on deep-blue emission carbon dots (CDs) has been proposed in this study. The as-prepared CDs exhibited a quantum yield close to 100% and a high exciton binding energy. The CDs-based ELEDs provided deep-blue emission at a wavelength of 450 nm, with CIE coordinates of (0.15, 0.07), closely approaching the standard color of the Rec. 2020 specification (0.131, 0.046). These results provide sufficient evidence that the devices fabricated in this work are one of the highest-performing CDs-based ELEDs developed so far, providing a quantum efficiency of over 10%.