Coplanar Conformational Structure of π‐Conjugated Polymers for Optoelectronic Applications

Hierarchical structure of conjugated polymers is critical to dominating their optoelectronic properties and applications. Compared to nonplanar conformational segments, coplanar conformational segments of conjugated polymers (CPs) demonstrate favorable properties for applications as a semiconductor. Herein, recent developments in the coplanar conformational structure of CPs for optoelectronic devices are summarized. First, this review comprehensively summarizes the unique properties of planar conformational structures. Second, the characteristics of the coplanar conformation in terms of optoelectrical properties and other polymer physics characteristics are emphasized. Five primary characterization methods for investigating the complanate backbone structures are illustrated, providing a systematical toolbox for studying this specific conformation. Third, internal and external conditions for inducing the coplanar conformational structure are presented, offering guidelines for designing this conformation. Fourth, the optoelectronic applications of this segment, such as light‐emitting diodes, solar cells, and field‐effect transistors, are briefly summarized. Finally, a conclusion and outlook for the coplanar conformational segment regarding molecular design and applications are provided. The coplanar conformational segment of π‐conjugated polymer is a unique structure with a rigid backbone, long effective conjugated length, and narrow bandgap, which may enhance emission behavior, strengthen π‐electron delocalization, and improve charge transport. This overview mainly reports the recent development of coplanar conformational structure of π‐conjugated polymers. The characteristics, analysis methods, preparation, and their optoelectronic application are introduced and summarized systematically.