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

Abstract

Carbon dots (CDs) sourced from sustainable natural resources have emerged as promising 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 the temperature and time of the synthesis conditions, yielding WLE-CDs, which remain challenging despite their potential in advancing CD-based white-light-emitting diode (WLED) technology. Notably, under 410 nm excitation, the CDs exhibited emission covering the entire visible spectrum, with a quantum yield of 34.96%. In order to capitalize on this, a WLED was fabricated with CIE coordinates of (0.31, 0.34), a CRI of 81%, and a CCT of 6467 K with a cool white tone suited for functional and high-visibility environments. This study outlines the potential of biomass-derived CDs as a sustainable white phosphor material for optoelectronic applications.