Gram-Scale Preparation of Long-Wavelength Emitting Fluorescent Tunable Carbon Dots for WLEDs

Currently, long-wavelength carbon dots have garnered widespread attention from researchers due to their unique luminescent properties. However, the industrial-scale production of carbon dots presents an inevitable challenge. This study successfully synthesized long-wavelength, fluorescence-tunable carbon dots (T-CDs) in gram-scale yield using a one-pot solvothermal method, followed by simple water washing for purification. The synthesized T-CDs exhibited tunable fluorescence in different solvents due to the combined effects of solvent polarity and hydrogen bond donor. Furthermore, solid-state tunable fluorescence was achieved in various matrices, and light-emitting diodes with various emission colors were prepared. High-efficiency white light-emitting diodes were fabricated based on T-CDs, exhibiting CIE color coordinates of (0.35, 0.35), a color rendering index of 91, and excellent luminescence performance and photostability. This study provides a straightforward method for gram-scale preparation of long-wavelength carbon dots, holding significant value in achieving tunable fluorescence in solution, the solid state, and high-performance lighting applications.