Green-light-emitting carbon dots via eco-friendly route and their potential in ferric-ion detection and WLEDs

Abstract

As a rising star in the carbon family, carbon dots (CDs) have been attracting tremendous interest in the scientific community by virtue of their unique physicochemical, optical, and electronic properties. In particular, CDs in the solid state are strongly desired for their potential applications in light-emitting devices due to their simplicity of preparation and enhanced photoluminescence (PL) performance. Fortunately, a microwave-assisted solvent-free approach is proposed here for the first time to rapidly obtain green-light-emitting carbon dots (G-CDs). G-CDs with a maximum emission wavelength of 521 nm were achieved, for which the photoluminescence quantum yield and production yield are as high as 48.8% and 59.15%, respectively. Moreover, the G-CDs have a uniform size distribution, and good thermal and pH stability, enabling the highly sensitive detection of Fe³⁺ with a limit as low as 10 μM and potential in CD-based white-light-emitting diodes (WLEDs). Typically, the G-CD-based WLEDs favorably emit white light with a color rendering index of 92.2 and Commission internationale de l’éclairage (CIE) coordinates of (0.3437, 0.3358), demonstrating good color chromatic stability. On account of its environmental friendliness, simplicity, high efficiency, and low cost, this approach is promising for the scaled-up production of CDs, and may promote their application in detection sensors and high-performance light-emitting devices.