Facile way to fabricate high quality white LED with yellow graphene quantum dots

Abstract

Because of the fabulous fluorescence characteristics, semiconductor quantum dots have attracted a lot attention since the first reported. Meanwhile, the applications of quantum dots have been limited by its own toxicity. The appearance of graphene quantum dots (GQDs) breaks the awkward situation. GQDs can also realize from ultraviolet to near infrared full visible light broad band emitting. The lower cost, better biocompatibility and stability than semiconductor quantum dots make it possible to replace inorganic quantum dots for chemical sensing, biomarkers, and optoelectronic devices. In this paper, the synthesis of doped GQDs is mainly studied. The nitrogen-chlorine doped GQDs were synthesized by hydrothermal method. The as prepared GQDs were characterized by TEM, XPS, FTIR, PL and other characterization methods. In this study, by utilizing common industrialized technology to fabricate GQDs white LED could achieve large-scale production. The rendering index of as prepared white GQDs LED was 85.4. It is much higher than YAG phosphor white LED. And the chromaticity coordinates of GQDs LED located at (0.34, 0.36). The correlated color temperature of 5075K was very consistent with indoor lighting scene. That means this GQDs white LED has great application prospects in the field of high-end lighting.