Preparation of medium-long wavelength aggregation aggregation-induced emission carbon dots induced by nitrogen and sulfur doping

Abstract

Carbon dots (CDs) are extensively employed across multiple fields due to their exceptional optical properties, stability and other advantages. However, the aggregation-caused quenching (ACQ) phenomenon has impeded the development of CDs in solid-state luminescence applications, including anti-counterfeiting and color display devices. In this study, we synthesized multicolor solid-state fluorescent CDs via the solvothermal reaction of dithiosalicylic acid with three different amine molecules, using acetic acid as the solvent. The resulting CDs demonstrate dual fluorescence emissions in solution, with the long-wavelength emission exhibiting typical aggregation-induced emission (AIE) characteristics. In the solid state, the synergistic effects of enhanced sp² conjugation domains and increased graphitic nitrogen on the surfaces of the CDs result in a red shift in fluorescence. The AIE phenomenon is achieved by restricting the intramolecular motion of the disulfide -containing bonds present on the surfaces of the CDs. Utilizing their unique dual emission properties, excellent AIE characteristics and tunable fluorescence colors. These CDs are intended for applications in information anti-counterfeiting, fingerprint detection and optoelectronics.