Narrow‐Bandwidth Emissive Carbon Dots: Regulation of Optical Properties and Applications

Abstract Narrow‐bandwidth emissive carbon dots (NBE‐CDs) are a new class of narrow‐bandwidth emissive fluorescent materials, with the advantages of abundant sources, easy modification, low toxicity, low cost, and solution processing. Compared with traditional carbon dots, NBE‐CDs exhibit narrow full width at half maximum (FWHM), endowing them with unique properties, such as high spectral resolution, high color purity, and high photoluminescence quantum yield, and consequently making them ideal candidates for advanced applications in optoelectronic devices, chemical sensing, and bioimaging. This review summarizes the research progress of NBE‐CDs in recent years, including synthesis methods, FWHM regulation, and applications. Most of all, the regulation strategy of the FWHM of NBE‐CDs in liquid/solid state is highlighted, aiming at clarifying the relationship among the structure of carbon sources, the structure of NBE‐CDs, and their FWHM property. Besides, the existing challenges and prospects of NBE‐CDs are discussed, expecting to further promote the practical applications of NBE‐CDs in multiple fields.