Synthesis of single-particle level white-light-emitting carbon dots via a one-step microwave method

Abstract

A simple yet environmentally friendly and cost effective preparation method of white light emitting carbon dots (Cdots) is reported. The as-synthesized Cdots exhibit emission spectrum covering the entire visible region with color coordinates close to that of pure white light with high color rendering index (84–89) and variable correlated color temperature (5593–7490 K). In depth analytical characterization suggested that white light emission originated from single Cdot particles, which was corroborated by single particle imaging and a corresponding emission spectrum obtained using confocal laser scanning microscope. White light emitting capability of Cdots was found to be retained even when they were embedded in a polyvinyl alcohol (PVA) solid polymer matrix. The ease of synthesis combined with unique optical properties make these heavy-metal ion-free Cdots potential candidates for applications in light-emitting diodes and full-color display panels.