Boosting Organic Afterglow Performance via a Two-Component Design Strategy Extracted from Macromolecular...

Area of Science:

• Materials Science
• Organic Chemistry
• Photophysics

Background:

• Achieving efficient organic afterglow is challenging due to spin-forbidden intersystem crossing and phosphorescence decay.
• Macromolecular self-assembly offers a strategy for designing advanced functional materials.

Purpose of the Study:

• To fabricate high-performance room-temperature organic afterglow materials.
• To control excited state properties of difluoroboron β-diketonate (BF₂bdk) compounds using synthetic polymers.

Main Methods:

• Utilized a two-component design strategy combining synthetic polymers with BF₂bdk and deuterated BF₂bdk compounds.
• Investigated polymer-BF₂bdk interactions, including dipole-dipole interactions, to tune excited state energy levels (S₁, T₁) and energy gaps (ΔE_ST).
• Assessed the impact of polymers on intramolecular motion and oxygen quenching of BF₂bdk triplets.

Main Results:

• Polymer component effectively lowered BF₂bdk S₁ levels while minimally affecting T₁ levels, reducing ΔE_ST and enhancing intersystem crossing.
• Polymers suppressed intramolecular motion and protected BF₂bdk triplets from oxygen quenching.
• Resulting BF₂bdk-polymer materials showed emission lifetimes up to 2.2 s, high photoluminescence quantum yields, and excellent processability.

Conclusions:

• Synthetic polymers can effectively control excited state properties for high-performance organic afterglow materials.
• The developed materials exhibit excellent ambient performance, flexibility, and processability.
• These materials serve as efficient donors for energy transfer, enabling the construction of red afterglow systems.