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Donor-acceptor (D-A) conjugated polymers comprising electron-deficient aromatic dicarboximide units represent an important type of organic semiconductors, especially for electron transporting properties. Pyrene-1,5,6,10-tetracarboxyl diimide (PyDI), a new PAH dicarboximide molecule recently reported by us, provides a fine balance between the electron-stabilizing ability and π-stacking tendency, as compared to the naphthalenediimide (NDI) and perylenediimide (PDI) analogues. In this study, using thienylene-vinylene-thienylene (TVT) and biselenophene (BS) as the electron donating comonomer, along with PyDI as the acceptor moiety, we develop two new D-A type conjugated polymers, which exhibit impressive electron-transporting performance. Specifically, in the solution-processed OFET devices, electron mobility of 0.18 and 0.20 cm2·V−1·s−1 are achieved with these polymers, respectively. Such findings further prove the optimal potential of PyDI for application as an electron-acceptor building block in the development of polymeric n-type semiconductors among all various high-performance functional D-A polymers. [ABSTRACT FROM AUTHOR]

Despite the remarkable synthetic accomplishments in creating diverse polycyclic aromatic hydrocarbons with B−N bonds (BN‐PAHs), their optoelectronic applications have been less exploited. Herein, we report the achievement of high‐mobility organic semiconductors based on existing BN‐PAHs through a "periphery engineering" strategy. Tetraphenyl‐ and diphenyl‐substituted BN‐anthracenes (TPBNA and DPBNA, respectively) are designed and synthesized. DPBNA exhibits the highest hole mobility of 1.3 cm2 V−1 s−1 in organic field‐effect transistors, significantly outperforming TPBNA and all the reported BN‐PAHs. Remarkably, this is the first BN‐PAH with mobility over 1 cm2 V−1 s−1, which is a benchmark value for practical applications as compared with amorphous silicon. Furthermore, high‐performance phototransistors based on DPBNA are also demonstrated, implying the high potential of BN‐PAHs for optoelectronic applications when the "periphery engineering" strategy is implemented. [ABSTRACT FROM AUTHOR]

Doping has been widely used to control the charge carrier concentration in organic semiconductors. However, in conjugated polymers, n-doping is often limited by the tradeoff between doping efficiency and charge carrier mobilities, since dopants often randomly distribute within polymers, leading to significant structural and energetic disorder. Here, we screen a large number of polymer building block combinations and explore the possibility of designing n-type conjugated polymers with good tolerance to dopant-induced disorder. We show that a carefully designed conjugated polymer with a single dominant planar backbone conformation, high torsional barrier at each dihedral angle, and zigzag backbone curvature is highly dopable and can tolerate dopant-induced disorder. With these features, the designed diketopyrrolopyrrole (DPP)-based polymer can be efficiently n-doped and exhibit high n-type electrical conductivities over 120 S cm−1, much higher than the reference polymers with similar chemical structures. This work provides a polymer design concept for highly dopable and highly conductive polymeric semiconductors. In conjugated polymers, n-doping is often limited by the tradeoff between doping efficiency and charge carrier mobilities, since dopants often randomly distribute within polymers, leading to significant structural and energetic disorder. Here, the authors screen a large number of polymer building block combinations and explore the possibility of designing n-type conjugated polymers with good tolerance to dopant-induced disorder. [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]

A new electron-deficient unit with a fused 5-membered heterocyclic ring was developed by replacing a cyclopenta-1,3-diene from electron-rich donor indacenodithiophene (IDT) with a cyclohepta-4,6-diene-1,3-diimde unit. The imide bridge endows dithienylbenzenebisimide (BBI) with a fixed planar configuration and low energy levels for both the highest occupied molecular orbital (HOMO; −6.24 eV) and the lowest unoccupied molecular orbit (LUMO; −2.57 eV). Organic field-effect transistors (OFETs) based on BBI polymers exhibit electron mobility up to 0.34 cm2 V−1 s−1, which indicates that the BBI is a promising n-type building block for optoelectronics. [ABSTRACT FROM AUTHOR]

A thiophene-fused polycyclic azaborine skeleton was employed into conjugated polymers for organic field-effect transistors for the first time. Two polythiophene-type polymers were developed, which exhibited low HOMO levels and strong intermolecular interactions, leading to a hole mobility of up to 0.38 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

Recently, many efforts have been devoted to developing novel polycyclic aromatics due to their unique optical and electronic properties and broad applications, such as in organic field-effect transistors, organic photovoltaics, and organic light-emitting diodes. Among various π-conjugated molecules, many truxene derivatives have interesting characteristics such as C3-symmetry, strong blue emission, and a planar rigid structure. Moreover, compared with many other π-conjugated aromatics, the synthesis and modification of truxene are particularly facile and diverse. In this account, we summarize investigations into truxene derivatives from synthesis and physical properties to applications in organic electronics. [ABSTRACT FROM AUTHOR]

Inthe past couple of years, remarkable progress has been madein solution-processable organic semiconducting materials for optoelectronics.The development of novel π-conjugated backbones has always beenthe central issue in this field. In contrast, flexible side chainsare less developed and usually used only as solubilizing groups. Inthis Perspective, we highlight the effects of the flexible chainsin organic semiconductors, including the influences of length, odd–eveneffect, substitution position, terminal groups, branching position,and chirality of alkyl chains, as well as some significant featuresof oligo(ethylene glycol) and fluoroalkyl chains. Although the rolesof flexible chains in organic semiconducting materials are complexand differ when corresponding conjugated skeleton changes, in thisPerspective, we emphasize the synergy of conjugated backbones andflexible side chains, which might significantly facilitate the understandingof the roles of flexible chains in structure–property relationshipand promote the development of high-performance organic semiconductors. [ABSTRACT FROM AUTHOR]

A new family of sulfur-heteroarenes with a chrysene core was developed. Top-contact FET devices were fabricated with hole mobility up to 0.4 cm2V−1s−1. The results suggest that in addition to the much explored linear acenes, molecules with a nonlinearly fused core could also be used as active material in high-performance OFET. [ABSTRACT FROM AUTHOR]