White light emitting diode and anti-counterfeiting applications of microwave assisted synthesized green fluorescent carbon dots derived from waste curry leaves

Abstract

We have prepared waste curry leaves extract derived carbon dots (CL-C dots) by microwave assisted method. The synthesized CL-C dots were well characterized by many techniques. Using HR-TEM images, the size of the synthesized CL-C dots were determined to be 3.55 nm. CL-C dots exhibits green fluorescence and obtained emission maximum at 425 nm upon the excitation at 340 nm. The green emissive CL-C dots quantum yield (QY) was determined to be 27.13%. The intensity ratio of ID/IG was, as calculated as 1.1 from the Raman spectrum. Moreover, CL-C dots were successfully applied for the preparation of the White Light Emitting Diode (WLED) device. The developed WLED has a colour coordinate value of (0.307, 0.354) and a colour correlated temperature of 6617 K. Finally, we have been used CL-C dots for anti-counterfeiting fluorescent ink application, it is a low-cost, simple-to-use substance that will eventually replace commercially available fluorescent inks. This research work offers a vision in the fields of materials science, WLED, energy, anti-counterfeiting and forensic science.