Adv. Mater.: Segregated Array Tailoring Charge-Transfer Degree of Organic Cocrystal for the Efficient Near-Infrared Emission beyond 760 nm

Segregated Array Tailoring Charge-Transfer Degree of Organic Cocrystal for the Efficient Near-Infrared Emission beyond 760 nm

Authors：

Ming-Peng Zhuo¹, Yi Yuan¹, Yang Su¹, Song Chen¹, Ye-Tao Chen², Zi-Qi Feng¹, Yang-Kun Qu¹, Ming-De Li², Yang Li³, Bing-Wen Hu³, Xue-Dong Wang¹*, and Liang-Sheng Liao^1,4*

Institutions：

¹Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices，Soochow University，Suzhou 215123，China

²Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Providence, Shantou University, Shantou 515063, China.

³State Key Laboratory of Precision Spectroscopy, Shanghai Key Laboratory of Magnetic Resonance, Institute of Functional Materials, School of Physics and Materials Science, East China Normal University, Shanghai 200062, China.

⁴Macao Institute of Materials Science and Engineering Macau, University of Science and Technology, Taipa, Macau SAR 999078, China

Abstract：

Harvesting the narrow bandgap excitons of charge-transfer (CT) complexes for the achievement of near-infrared (NIR) emission has attracted intensive attention for its fundamental importance and practical application. Herein, the triphenylene (TP)-2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄TCNQ) CT organic complex is designed and fabricated via the supramolecular self-assembly process, which demonstrates the NIR emission with a maximum peak of 770 nm and a photoluminescence quantum yield (PLQY) of 5.4%. The segregated stacking mode of TP-F₄TCNQ CT complex based on the multiple types of intermolecular interaction has a low CT degree of 0.00103 and a small counter pitch angle of 40° between F₄TCNQ and TP molecules, which breaks the forbidden electronic transitions of CT state, resulting in the effective NIR emission. Acting as the promising candidates for the active optical waveguide in the NIR region beyond 760 nm, the self-assembled TP-F₄TCNQ single-crystalline organic microwires display an ultralow optical-loss coefficient of 0.060 dB μm⁻¹. This work holds considerable insights for the exploration of novel NIR-emissive organic materials via an universal “cocrystal engineering” strategy.

IF：

30.849

Link：

https://onlinelibrary.wiley.com/doi/full/10.1002/adma.202107169