Multicolor Carbon Dots with Purple-to-Red Emission for Fluorescent Inks and LEDs Applications

Carbon dots (CDs) present substantial potential in bioimaging, sensing, catalysis, and optoelectronic devices due to their distinctive fluorescent properties, low toxicity, and excellent biocompatibility. Nevertheless, achieving multicolor-tunable fluorescence emission across the entire visible spectrum remains a significant challenge. Recent research has focused on solvothermal synthesis routes to address this, demonstrating the ability to produce a series of multicolor-emitting CDs (p-CDs to r-CDs) by utilizing precursors such as citric acid, benzoic acid, and catechol. This approach enables the creation of multicolor fluorescent inks that exhibit distinct, non-interfering five-color emission under 365 nm ultraviolet (UV) irradiation, indicating promise in anti-counterfeiting and labeling applications. Furthermore, the successful fabrication of red-light-emitting diodes (LEDs) using specific CDs (e.g. r-CDs) demonstrates their viability for advanced lighting and display technologies. These LEDs exhibit an electroluminescence peak at 586 nm and CIE color coordinates of (0.54, 0.43), highlighting their potential for high-performance applications.