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Updated: Jun 4, 2025

ARL Spectral Fitting as an Application to Augment Spectral Data via Franck-Condon Lineshape Analysis and Color Analysis
Published on: August 19, 2021
Highly efficient NIR-Ⅱ window photoluminescence up to 1000 nm using heteroatomic fused-ring radicals
Jun-Yang Hui1, Hai-Ping Zhou2, Ying Sun1
1School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin Provincial Science and Technology Innovation Center of Optical Materials and Chemistry, Jilin Provincial International Joint Research Center of Photo-functional Materials and Chemistry, Changchun 130022, China.
Abstract:
Neutral radicals have the potential to construct pure organic light-emitting diodes (OLEDs) with internal quantum efficiencies reaching 100%. However, neutral radical luminescent materials with emission wavelengths in the second near-infrared (NIR-II) window are rare. Herein, a serial of neutral donor-bridge-acceptor (D-π-A) type radical derivatives are investigated. The dominant elements influencing the luminescent properties of neutral radicals, such as chemical stability, excited state characteristics, radiative decay rate (kr) and internal conversion rate (kIC) constants are taken into consideration. Theoretical calculations reveal that introducing heteroatomic fused-rings into neutral radicals can modulate the chemical stability and result in a red shift of the emission wavelength spectrum. In the presence of charge transfer characteristics, by increasing the effective overlap between the hole and electron wavefunctions, the kr constants of the neutral D-π-A type radicals increase. In addition, avoiding the geometric relaxation between the lowest excited state (D1) and the ground state (D0), as well as reducing electron-vibration coupling and non-adiabatic coupling in the low-frequency region can effectively decrease the kIC constants. Our study proposes an innovative design approach aiming to develop stable and efficient NIR-II window neutral radical luminescent materials utilizing heteroatomic fused-rings as key elements.
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