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Updated: Jun 12, 2026

Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
Published on: May 27, 2020
Molecular conformation engineering in central 8π-electron system toward unique aggregation-induced ultra-narrowband
Lu Liu1, Han Zhang2,3, Chenfa Xiao1
1State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China.
Abstract:
Organic emitters with narrowband emission characteristics demonstrate significant advantages and application potential in ultra-high-definition displays and multiplexed fluorescence imaging. However, the obstinate spectral broadening phenomenon upon aggregation limits the practical application of organic narrowband emissive materials. Here, a referable strategy on conformation engineering is proposed in a central 8π-electron system with narrowband emissions in both solution and aggregate. Owing to the synergistic effect of strain-release-driven conformational planarity in ground state and excited-state aromaticity-driven planarity, PDBP-b,i exhibits minimal structural change between the S0 and S1 states, resulting in narrowband emission in solution with a full width at half maximum (FWHM) of 35 nm/0.24 eV. While in aggregate, the cross dipole stacking mode further confines molecular conformation and restricts high-frequency vibration, additionally narrowing with a record-small FWHM of 13 nm/0.08 eV. The concept of aggregation-induced ultra-narrowband emission is proposed, which also offers advantages in electroluminescence to exhibit a small FWHM of 13 nm and remaining stable as the concentration increases. These results provide new insights and instructive guidance for the design of organic narrowband emitters.
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