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It remains challenging to comprehensively understand the packing models of conjugated polymers, in which side chains play extremely critical roles. The side chains are typically flexible and non‐conductive and are widely used to improve the polymer solubility in organic solutions. Herein, a buffer chain model is proposed to describe link between conjugated backbone and side chains for understanding the relationship of crystallization competition of conductive conjugated backbones and non‐conductive side chains. A longer buffer chain is beneficial for alleviating such crystallization competition and further promoting the spontaneous packing of conjugated backbones, resulting in enhanced charge transport properties. Our results provide a novel concept for designing conjugated polymers towards ordered organization and enhanced electronic properties and highlight the importance of balancing the competitive interactions between different parts of conjugated polymers. [ABSTRACT FROM AUTHOR]

Conjugated polymers that can efficiently transport both ionic and electronic charges have broad applications in next‐generation optoelectronic, bioelectronic, and energy storage devices. To date, almost all the conjugated polymers have hydrophobic backbones, which impedes efficient ion diffusion/transport in aqueous media. Here, we design and synthesize a novel hydrophilic polymer building block, 4a‐azonia‐naphthalene (AN), drawing inspiration from biological systems. Because of the strong electron‐withdrawing ability of AN, the AN‐based polymers show typical n‐type charge transport behaviors. We find that cationic aromatics exhibit strong cation‐π interactions, leading to smaller π–π stacking distance, interesting ion diffusion behavior, and good morphology stability. Additionally, AN enhances the hydrophilicity and ionic‐electronic coupling of the polymer, which can help to improve ion diffusion/injection speed, and operational stability of organic electrochemical transistors (OECTs). The integration of cationic building blocks will undoubtedly enrich the material library for high‐performance n‐type conjugated polymers. [ABSTRACT FROM AUTHOR]

Introducing BN units into polycyclic aromatic hydrocarbons expands the chemical space of conjugated materials with novel properties. However, it is challenging to achieve accurate synthesis of BN‐PAHs with specific BN positions and orientations. Here, three new parent B2N2‐perylenes with different BN orientations are synthesized with BN‐naphthalene as the building block, providing systematic insight into the effects of BN incorporation with different orientations on the structure, (anti)aromaticity, crystal packing and photophysical properties. The intermolecular dipole–dipole interaction shortens the π–π stacking distance. The crystal structure, (anti)aromaticity, and photophysical properties vary with the change of BN orientation. The revealed BN doping effects may provide a guideline for the synthesis of BN‐PAHs with specific stacking structures, and the synthetic strategy employed here can be extended toward the synthesis of larger BN‐embedded PAHs with adjustable BN patterns. [ABSTRACT FROM AUTHOR]

Molecular doping plays an important role in the modification of carrier density of organic semiconductors thus enhancing their optoelectronic performance. However, efficient n‐doping remains challenging, especially owing to the lack of strongly reducing and air‐stable n‐dopants. Herein, an N‐heterocyclic carbene (NHC) precursor, DMImC, is developed as a thermally activated n‐dopant with the excellent stability in air. Its thermolysis in situ regenerates free NHC and subsequently dopes typical organic semiconductors. In sequentially doped FBDPPV films, DMImC does not disturb the π–π packing of the polymer and achieves good miscibility with the polymer. As a result, a high electrical conductivity of up to 8.4 S cm−1 is obtained. Additionally, the thermally activated doping and the excellent air stability permit DMImC to be noninteractively co‐processed with polymers in air. Our results reveal that DMImC can be served as an efficient n‐dopant suitable for various organic semiconductors. [ABSTRACT FROM AUTHOR]