Multicolor and Single-Component White Light-Emitting Carbon Dots from a Single Precursor for Light-Emitting Diodes

The preparation of multicolor and white light-emitting carbon dots (CDs) is of both significant importance and challenging for their applications as white phosphors for light-emitting diodes (LEDs). In this report, a facile reaction system that is capable of preparing both multicolor and white light-emitting CDs was disclosed. In this system, three CDs emitting yellow, red, and green lights were prepared, and monochromatic LEDs were constructed using these multicolor CDs. Most importantly, single-component white light-emitting CDs with CIE coordinates of (0.33, 0.33) were also prepared. The white light-emitting CDs were applied as single-component white phosphors for the fabrication of white LEDs. The white LEDs constructed demonstrated excellent performance, emitting warm white light (CCT = 3723 K) with CIE coordinates of (0.39, 0.37) and an extremely high color-rendering index of 91.5, which should find favorable applications for indoor illumination.