Synthesis of Carbon Dots/PVP Composite for White Light Emitting Diode (WLED) Application

Carbon dots (CDs) are extensively utilized in biomedicine, optical devices, and sensing due to their low toxicity, excellent optical properties, and ease of synthesis. Nonetheless, there is ongoing discussion over the comprehensive investigation of CDs photoluminescence (PL) process because of their intricate architectures and surface functions. Carbon dots (CDs) and CD/PVP composites were one step synthesized in a hydrothermal process using citric acid and NaOH as precursors. Due to surface defects of CDs after incorporating into Polyvinylpyrrolidone (PVP) both shift in color as well as change in emission is observed. It shows the enhancement of the luminescence property of CDs/PVP and the application of CD/PVP composite in the field of optical emission. Further for practical application, emission of white light emitting diodes (WLEDs) was demonstrated by coating a 370 nm UV-LED with CD/PVP composite. The WLED shows significant CRI, good S/P ratio, the color gamut score Rg and color fidelity score Rf which are essential features for a good light source. Our research offers a valuable reference for CD/PVP composites in a facile, low temperature and low-cost hydrothermal process and developing WLED with UV-LED and metal free phosphors.