Assembly-Independent Intramolecular Chiroptical Amplification in Figure-Eight-Shape Multi-Resonance Emitters:...

Area of Science:

• Organic electronics
• Materials science
• Photophysics

Background:

• Chirality incorporation into multi-resonance (MR) frameworks is key for narrowband circularly polarized luminophores.
• Existing methods face challenges due to decoupling between chiral perturbation and MR-confined radiative transitions.
• Self-assembly strategies for chirality amplification are limited by morphology-dependent order, hindering efficient electroluminescence.

Purpose of the Study:

• To establish a self-assembly-independent intramolecular amplification strategy for chiral luminophores.
• To enhance chiral exciton interactions within a multi-resonance framework while maintaining efficient emission.
• To develop solution-processed organic electroluminescent (EL) devices with high circularly polarized emission.

Main Methods:

• Design and synthesis of a C2-symmetric figure-eight macrocyclic MR architecture.
• Theoretical calculations to analyze transition-symmetry control and through-space interchromophoric coupling.
• Fabrication and characterization of solution-processed organic electroluminescent (EL) devices.

Main Results:

• The novel architecture strengthens intramolecular chiral exciton interactions and preserves intrinsic MR emission.
• The developed material (TmCz-[10]AD) exhibits narrowband emission, fast reverse intersystem crossing (2.31 × 10^5 s^-1), and high photoluminescence quantum yield.
• Achieved a dissymmetry factor (|gPL|) approaching 10^-2, enabling EL devices with >20.5% external quantum efficiency and an |gEL| of 6.2 × 10^-3.

Conclusions:

• The intramolecular amplification strategy overcomes limitations of previous approaches.
• The C2-symmetric figure-eight macrocyclic MR architecture is effective for developing efficient chiral luminophores.
• This work paves the way for high-performance solution-processed circularly polarized organic light-emitting diodes (OLEDs).