Facile synthesis of high-brightness green-emitting carbon dots with narrow bandwidth towards backlight display

High-performance carbon dots (CDs) allowing the application in high-end display devices are highly desirable and usually limited by the absence of simple and easy synthesis methods. In this work, we exploited an easy-to-implement strategy for the one-step synthesis of green-emitting CDs (G-CDs) with superb optical properties. The G-CDs were synthesized using m-phenylenediamine (m-PD) as a single precursor, and the reaction reacted at 180 °C for 12 h. The resultant G-CDs exhibit high-purity and excitation-independent green fluorescence with the photoluminescence (PL) peak located at 516 nm, full width at half maximum (FWHM) of 46 nm, and PL quantum yield (QY) of ∼80% under the 470 nm excitation light. The G-CDs and corresponding composite film prepared with polyvinyl butyral (G-CDs@PVB) exhibit good PL stability after undergoing long-time storage for one year and 360 h exposure under 460 nm blue light. The G-CDs@PVB film was used as color-conversion materials in green-emitting light-emitting diode (LED) application, exhibiting a Commission internationale de l'Eclairage (CIE) chromaticity coordinate of (0.21, 0.44). The film was also used in CD-based liquid crystal display (CD-LCD) application, achieving a color gamut value of 85%. This work will offer a working basis for the synthesis of high-performance CDs as well as their application in displays.