Vacuum-Assisted Synthesis of Solid-State Fluorescent Carbon Quantum Dots for Color Conversion LEDs

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Carbon dots (CDs) are versatile nanomaterials with tunable optical properties and biocompatibility.
• Challenges exist in producing stable, effective, and adjustable solid-state fluorescent CDs.
• Existing methods often struggle with luminescence quenching in solid forms.

Purpose of the Study:

• To develop a simple, scalable method for producing solid-state green-emissive carbon dots.
• To investigate the role of a boric acid matrix in enhancing CD fluorescence and stability.
• To demonstrate the application of these solid-state CDs in color-conversion devices.

Main Methods:

• Vacuum-assisted synthesis using urea, trisodium citrate dihydrate, and boric acid matrix.
• Fabrication of solid-state films and aqueous solutions of CDs.
• Characterization of photoluminescence quantum yield (PLQY) and CIE coordinates.
• Fabrication of color-conversion light-emitting devices.

Main Results:

• Solid-state green-emissive CDs were successfully synthesized using a boric acid matrix.
• The boric acid matrix significantly enhanced PLQY in solid-state CDs compared to those without the matrix.
• The matrix reduced aggregation-induced quenching, improving fluorescence.
• Adjustable CIE coordinates were achieved, enabling device fabrication.

Conclusions:

• A viable and scalable method for stable, efficient solid-state fluorescent CDs was established.
• Boric acid matrix is crucial for maintaining high fluorescence in solid-state CDs.
• These B-CDs show promise for applications in flexible lighting and color conversion devices.