Red-emitting carbon dots phosphors: a promising red color convertor toward warm white light emitting diodes

Various luminescent carbon materials are artificially synthesized and as admirable fluorescent materials because of the increased research of carbon nanodots (CDs). Herein, a novel solvent-dependent red CDs (rCDs) is introduced through solvothermal method. The as-prepared rCDs remain benzene structure and possess abundant surface function groups that endow them well solubility in various solvents. Furthermore, multicolor luminescence are observed when rCDs are dissolved in different solvents, and the emission wavelength of these materials can be well-tuned from 475 to 624 nm, which presents intensity solvent-dependent properties. Red luminescence carbon phosphors are successfully synthesized by mix rCDs with silica powder. Finally, warm white light emitting diodes (WLEDs) are constructed using rCDs powder with Ce3+: YAG single crystal and blue GaN chips. The results demonstrate that the rCDs can act as red component to modify the correlated color temperature (CCT) and the color rendering index (CRI) of WLEDs .