Multicolor Carbon Dots for Warm White Light-Emitting Diodes with a High Color Rendering Index of 93.2
Qiurui Han, Wenjun Xu, Jiwen Deng, Xingshou Zhang, Jiaqing Li, Zhili Peng
Abstract
Multicolor carbon dots (CDs) with compatible physical and chemical properties have tremendous potential applications in full-color display and photoelectric devices. In this work, red, green, and blue-emissive CDs (R-, G-, and B-CDs) were synthesized from o-, m-, and p -phenylenediamine under identical reactions for the first time. Mechanism exploration has shown that the photoluminescence of G- and B-CDs was dominantly core-state emissions while that of R-CDs was also heavily influenced by surface-state emissions. Superior WLEDs were fabricated exploiting the three CDs as compositing white phosphors, emitting warm white light with a correlated color temperature of 3248 K, CIE coordinates of (0.41, 0.38), and a high color rendering index value of 93.2, surpassing most phenylenediamine-derived CDs WLEDs. Most importantly, the WLEDs also demonstrated high stabilities under different working conditions and environments, highlighting their practicality.