53% Efficient Red Emissive Carbon Quantum Dots for High Color Rendering and Stable Warm White‐Light‐Emitting Diodes

Red emissive carbon quantum dots (R‐CQDs) with quantum yield of 53% is successfully prepared. An ultraviolet (UV)‐pumped CQD phosphors‐based warm white light‐emitting diode (WLED) is realized for the first time and achieves a color rendering index of 97. This work provides a new avenue for the exploration of low cost, environment‐friendly, and high‐performance CQD phosphors‐based warm WLEDs.