High-efficiency NP-carbon dots above 60% with both delayed fluorescence and room-temperature phosphorescence

Area of Science:

• Materials Science
• Nanotechnology
• Photophysics

Background:

• Carbon dots (CDs) are versatile nanomaterials with unique optical properties.
• Developing CDs with efficient and long-lasting luminescence remains a key challenge.
• Simultaneous fluorescence and phosphorescence in CDs offer potential for advanced applications.

Purpose of the Study:

• To synthesize novel carbon dots (CDs) exhibiting both fluorescence and room-temperature phosphorescence.
• To characterize the photoluminescent properties, including quantum yield and lifetime.
• To explore the practical applications of these dual-emissive CDs.

Main Methods:

• Solvent-thermal reaction followed by thermal treatment for CD synthesis.
• Spectroscopic analysis to determine fluorescence and afterglow properties.
• Evaluation of quantum yield and afterglow lifetime.
• Demonstration of applications in anti-counterfeiting and optical information storage.

Main Results:

• Successful synthesis of carbon dots with simultaneous blue fluorescence and cyan afterglow.
• Achieved a high afterglow quantum yield (QY) of up to 60.47%.
• Observed an average afterglow lifetime of 1.11 s, with visual recognition up to 16 s.
• Demonstrated practical utility in anti-counterfeiting and optical information storage.

Conclusions:

• The developed carbon dots offer a promising platform for advanced luminescent materials.
• The straightforward synthesis and excellent afterglow properties make them suitable for security and data storage.
• This work contributes to the field of non-metallic afterglow materials and their applications.