8 research outputs found

    Правда коммунизма. 1961. № 092

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    Wide-bandgap conjugated polymers with a linear naphthacenodithiophene (NDT) donor unit are herein reported along with their performance in both transistor and solar cell devices. The monomer is synthesized starting from 2,6-dihydroxynaphthalene with a double Fries rearrangement as the key step. By copolymerization with 2,1,3-benzothiadiazole (BT) via a palladium-catalyzed Suzuki coupling reaction, NDT-BT co-polymers with high molecular weights and narrow polydispersities are afforded. These novel wide-bandgap polymers are evaluated as the semiconducting polymer in both organic field effect transistor and organic photovoltaic applications. The synthesized polymers reveal an optical bandgap in the range of 1.8 eV with an electron affinity of 3.6 eV which provides sufficient energy offset for electron transfer to PC70BM acceptors. In organic field effect transistors, the synthesized polymers demonstrate high hole mobilities of around 0.4 cm2 V–1 s–1. By using a blend of NDT-BT with PC70BM as absorber layer in organic bulk heterojunction solar cells, power conversion efficiencies of 7.5% are obtained. This value is among the highest obtained for polymers with a wider bandgap (larger than 1.7 eV), making this polymer also interesting for application in tandem or multijunction solar cells

    Crystal Engineering of Dibenzothiophenothieno[3,2-b]thiophene (DBTTT) Isomers for Organic Field-Effect Transistors

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    Three thiophene ring-terminated benzothieno[3,2-b]benzothiophene (BTBT) derivatives, C-C6-DBTTT, C-C12-DBTTT, and L-C12-DBTTT, were designed and synthesized, differing in the isomerization of alkyl chain position as well as aromatic core construction. A study of crystal structure and electronic properties combined with a theoretical investigation was performed to understand the structure–property relationships for the application of these molecules in organic field-effect transistors (OFETs). Different crystal packing structures were observed for these three isomers by single-crystal X-ray diffraction as a result of a crystal engineering molecular design approach. The highest charge-carrier mobility was observed for the isomer with a collinear core, L-C12-DBTTT. Preliminary results demonstrated a promising hole mobility of 2.44 cm2 V–1 s–1, despite the polymorphism observed in ambient conditions.info:eu-repo/semantics/publishe

    Isostructural, Deeper Highest Occupied Molecular Orbital Analogues of Poly(3-hexylthiophene) for High-Open Circuit Voltage Organic Solar Cells

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    We present the synthesis and characterization of two novel thiazole-containing conjugated polymers (<b>PTTTz</b> and <b>PTTz</b>) that are isostructural to poly­(3-hexylthiophene) (P3HT). The novel materials demonstrate optical and morphological properties almost identical to those of P3HT but with HOMO and LUMO levels that are up to 0.45 eV deeper. An intramolecular planarizing nitrogen–sulfur nonbonding interaction is observed, and its magnitude and origin are discussed. Both materials demonstrate significantly greater open circuit voltages than P3HT in bulk heterojunction solar cells. <b>PTTTz</b> is shown to be an extremely versatile donor polymer that can be used with a wide variety of fullerene acceptors with device efficiencies of up to 4.5%. It is anticipated that this material could be used as a high-open circuit voltage alternative to P3HT in organic solar cells
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