Recent advances in solid-state fluorescent of red carbon dots: A comprehensive review

Red-emissive carbon dots (R-CDs), as a novel type of carbon nanomaterial, have attracted extensive attention in various fields due to their unique properties and physicochemical characteristics. However, most of the reported R-CDs have mainly shown fluorescence in solution, which seriously limits their practical applications, especially in anticounterfeiting and optoelectronic device fields. In recent years, significant efforts have been devoted to achieving solid-state red fluorescence of CDs and exploring their potential applications. In this review, we analyzed the key issues in the synthesis of solid-state red carbon dots (SSR-CDs), elucidated the possible mechanisms of anti-quenching, and introduced their applications. Finally, we discuss the current challenges and opportunities of SSR-CDs.