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Magnetic absorbing material (MAM) embedded with electric ring resonator (ERR) is demonstrated to broaden the absorbing bandwidth in low-frequency range. We obtained the relation between input impedance and absorption bandwidth under specific reflection threshold to verify the influence of the embedded ERRs on impedance matching characteristic. Numerical simulations were carried out and the results are in agreement with theoretical analysis. We investigated the absorption mechanism through analyzing the distributions of electric and magnetic fields. The incidence angle sensitivity under different polarization modes is also discussed. It is demonstrated that the MAM with embedded-ERR increased the bandwidth under −10 dB from 1.73–3.17 to 1.48–3.87 GHz and 1.47–4.07 GHz for the TE-incidence and TM-incidence, which is 1.66 and 1.81 times wider than that of MAM, respectively. The proposed structure could broaden the absorption bandwidth in low-frequency range by means of introducing dual-band resonance in a single-layer medium. [ABSTRACT FROM AUTHOR]

Polychlorinated (hetero)arenes have shown great promise for organic optoelectronics applications. However, the harsh synthetic routes for polychlorinated compounds and the possible luminescence quenching from the compact intermolecular π-π stacking induced by chlorine atoms limit their investigations and applications in luminescent materials. Herein, two isomeric polychlorinated polycyclic aromatic hydrocarbon (PAH) compounds JY-1-Cl and JY-2-Cl consisting of rigidified aryl ketones and amine are designed and synthesized under mild conditions through nucleophilic chlorination intermediated by an electron donor-acceptor complex. Among them, as a result of the strong π-π interactions induced by chlorine atoms, JY-2-Cl exhibits bright monomer and dimer emissions with dual thermally activated delayed fluorescence (TADF) characters. Notably, compared with the non-chlorinated compounds, a high photoluminescence quantum yield is maintained after introducing multiple chlorine atoms into JY-2-Cl. The first dual-TADF organic light-emitting diodes are also successfully fabricated with maximum external quantum efficiency as high as 29.1 % by employing JY-2-Cl as emitter. This work presents a new paradigm and synthesis of polychlorinated amine-carbonyl PAHs and demonstrates the great potential of the chlorinated materials for luminescent applications., (© 2023 Wiley-VCH GmbH.)