Fluorescent carbon dot aggregates for optoelectronic applications

Abstract

The study of Solid-state fluorescent carbon dot (CD) aggregates has been done in two part. In the part one for synthesis solvothermal and precipitation methods has been used with reactants 2,2ʹ-dithiosalicylic acid with adenine or 4-aminobenzenethiol. The initially prepared CDs OD (from adenine) and GD (from 4-aminobenzenethiol) exhibited blue emission, but water treatment triggered a distinct shift to orange (ODA aggregates) and green (GDA aggregates) solid-state fluorescence. This emission switching stems from aggregation-induced emission (AIE) activated by water, with contact angle measurements confirming the hydrophobic surfaces of ODA and GDA. These ODA and GDA have been successfully applied in the fabrication of LEDs. In order to synthesize metal-doped CD aggregates with red fluorescence, synthesized by the same method using Nickel chloride, these hydrophobic aggregates demonstrated practical utility in fabricating fluorescent polymer covers for light-emitting diode (LED) devices, and the contact angle measurement of these CD aggregates is very significant. This type of hydrophobic contact angle may be used in metal corrosion protection applications. Additionally, their high fluorescence contrast enabled effective fingerprint detection, highlighting applications in forensic analysis and security systems.