Biomass-derived white light-emitting carbon dots for white LEDs

Abstract

Carbon dots (CDs) sourced from sustainable natural resources have emerged as prospective materials owing to their eco-friendly, cost-effective, size-dependent optical tunability for next-generation solid-state lighting. Here, we synthesized white-light-emitting carbon dots (WLE-CDs) via a one-pot solvothermal approach from the leaves of a medicinal plant, Epiphyllum oxypetalum, with CIE coordinates centered at (0.31, 0.33). Optimizations were done by varying temperature and time of the synthesis conditions, yielding WLE-CDs, which are challenging, despite their potential in advancing CDs-based White Light Emitting Diode (WLED) technology. Notably, at 410 nm excitation, the CDs exhibit emission covering the entire visible spectrum, with a quantum yield of 34.96%. To capitalize on this, WLED is fabricated with CIE coordinates (0.31, 0.34), a CRI of 81%, a CCT of 6467 K, and a cool white tone suited for functional and high-visibility environments. This work outlines the potential of biomass-derived CDs as a sustainable white phosphor material for optoelectronic applications.