Preparation of multicolor carbon dots with high fluorescence quantum yield and application in white LED

Using tartaric acid and triammonium citrate as environmentally friendly precursor reactants, multicolor fluorescent carbon dots with adjustable emission wavelength and high quantum yield were successfully synthesized via one-step solvothermal method by only changing the reaction solvent. The morphology, structure and optical properties of the carbon dots were investigated in detail. Characterization results showed that the as-synthesized carbon dots have good dispersibility, rich surface functional groups and high quantum yield (all over 40%). A high-quality white LED with CIE color coordinate (0.34, 0.35) was successfully fabricated using the prepared multicolor carbon dots as the light conversion material. The correlated color temperature was 5336 K, and the color rendering index was up to 83.1. The prepared LED emitted warm white light and was suitable for indoor lighting. It is of great significance to prepare multicolor carbon dots with high quantum yield by single-factor control, and the prepared multicolor carbon dots have potential and broad application prospects in the field of white LED.