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.

Organic photothermal cocrystals, integrating the advantages of intrinsic organic cocrystals and the fascinating photothermal conversion ability, hold attracted considerable interest in both basic science and practical applications, involving photoacoustic imaging, seawater desalination, and photothermal therapy, and so on. However, these organic photothermal cocrystals currently suffer individual cases discovered step by step, as well as the deep and systemic investigation in the corresponding photothermal conversion mechanisms is rarely carried out, suggesting a huge challenge for their further developments. Therefore, it is urgently necessary to investigate and explore the rational design and synthesis of high‐performance organic photothermal cocrystals for future applications. This review first and systematically summarizes the organic photothermal cocrystal in terms of molecular classification, the photothermal conversion mechanism, and their corresponding applications. The timely interpretation of the cocrystal photothermal effect will provide broad prospects for the purposeful fabrication of excellent organic photothermal cocrystals toward great efficiency, low cost, and multifunctionality.

The Front Cover shows integer‐charge‐transfer cocrystals are self‐assembled via multiple intermolecular hydrogen bonds with one electron transferred from donor to acceptor unit for high‐efficiency (∼87 %) NIR photothermal conversion. “D‐A pairs” as the basic “micro‐stacking units” in cocrystals guarantee strong donor‐acceptor interactions and excellent photothermal performance. Amorphous cocrystals synthesized by one‐step mechanochemical method exhibit good photo/thermal stability, which is highly desirable in practical large‐scale solar‐harvesting/conversion applications without the puzzle of maintaining an ideal stacking structure. More information can be found in the Research Article by S.‐L. Chen et al.