Highly Efficient Orange Emissive Graphene Quantum Dots Prepared by Acid-Free Method for White LEDs

Graphene quantum dots (GQDs) have wide prospective applications for optoelectronic fields owing to their unique characteristics, such as tunable bandgaps, high chemical and optical stability, as well as good biocompatibility. In this work, we offered a convenient proposal to obtain uniform blue-green emissive GQDs and modified efficient orange-emitting graphene quantum dots (D-GQDs) derived from fullerene (C-60) under acid-free conditions. The as-prepared D-GQDs demonstrate remarkable conversion efficiency, for which the quantum yield is up to 52.4% with an emission peak of 617 nm. Also, GQDs and D-GQDs were blended with poly(vinyl alcohol) (PVA) to prepare transparent photoluminescent films, which show excellent flexibility and preferable white emission property meeting the requirements of commercial white LEDs.