Fluorescent N-Doped Graphene Quantum Dots Embedded in Transparent Polymer Films for Photon-Downconversion Applications

Abstract

In this work, we demonstrate a simple, facile, and efficient one-pot synthesis of polymer-quantum dot nanocomposite films where nitrogen-doped graphene quantum dots (N-GQDs) were homogeneously dispersed in UV-curable, transparent polymer host matrix via the thiol-ene "click" reaction pathway. The highly fluorescent NOA-NGQD nanocomposite films exhibited strong hydrophobicity with water contact angle (>69 degrees) owing to restructuring of the polymer chain networks. The various functional groups of the N-GQD surface, as carbonyl, amine, and hydroxyl groups, provided more interactive sites and low agglomeration to develop the strong electrostatic interactions between the NOA and N-GQDs, resulting in flexible NOA-NGQDs nanocomposites. Thus, obtained NOA-NGQD nanocomposites exhibited high transparency (>90%), low band-gap, and strong fluorescence spectral peak (>500 nm) after the homogeneous inclusion of N-GQDs in the NOA polymer matrix. This study paves the way to diverse applications of functionalized GQDs as well as transparent polymers for the development of hydrophobic polymer-QD nanocomposites by using UV catalyzed thiol-ene chemistry. Hence, as synthesized nanocomposite films would be widely applicable in flexible electronic display devices, light emitting diodes (LEDs), and optoelectronic applications.