Bottom-Up Synthesized Carbon Nitride Quantum Dots-Based Light-Emitting Diode

Carbon nitride quantum dots (CNQDs) represent an emerging class of polymeric semiconductor nanomaterial that combines environmental friendliness with facile synthesis, solution-processability and tunable optoelectronic properties. Despite these advantages, their application in optoelectronics devices remains largely unexplored. Here we demonstrate a high-performance light-emitting diodes (LEDs) employing thermally polymerized CNQDs as the emissive layer. The synthesized CNQDs exhibit uniform size distribution, long-term colloidal stability, and a remarkable photoluminescence quantum yield. Detailed charge transport analysis reveals matched electron-hole mobility of CNQDs, enabling efficient radiative recombination. The optimized CNQDs-LED architecture achieves breakthrough performance metrics: a low turn-on voltage of 2.8 V, maximum luminance of 885 cd m-2, and record external quantum efficiency of 2.14%. This study not only establishes CNQDs as viable alternatives to conventional heavy-metal QDs but also provides a general framework for developing sustainable optoelectronic materials, paving the way for environmentally benign display technologies.