Twisted Structure Induced Solid-State Fluorescence and Room-Temperature Phosphorescence from Furan-Based Carbon Dots.

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Solid-state fluorescence (SSF) in carbon dots (CDs) is often induced by boron doping, but the underlying mechanism remains unclear.
• Understanding the relationship between boron doping, structural modifications, and optical properties in CDs is crucial for developing advanced materials.

Purpose of the Study:

• To investigate the intrinsic mechanism by which boron doping induces SSF and room-temperature phosphorescence (RTP) in furan-based carbon dots.
• To synthesize boron-doped CDs with aggregation-induced emission (AIE) properties and elucidate their structure-activity relationship.

Main Methods:

• Synthesis of boron-doped furan-based carbon dots (CDs).
• Morphological and structural characterization using advanced techniques.
• Photophysical studies to analyze fluorescence, AIE, and RTP properties.
• Computational analysis of molecular orbital overlap and energy levels.

Main Results:

• Boron doping induced structural twisting in the carbon dots.
• The twisted structure inhibited molecular motion and reduced nonradiative relaxation, leading to AIE.
• Twisted CDs showed reduced HOMO-LUMO overlap, decreasing singlet-triplet splitting energy (ΔEST).
• Boron-doped CDs embedded in microcrystalline cellulose exhibited green RTP due to suppressed nonradiative transitions.

Conclusions:

• Boron doping induces structural twisting in CDs, which is key to their AIE and RTP properties.
• The study establishes a structure-activity relationship for light-emitting CDs, offering a novel approach for their design.
• This work provides fundamental insights into the photoluminescence mechanisms of doped carbon dots for solid-state applications.