Publications
293 results found
Paterson AF, Tsetseris L, Li R, et al., 2019, Addition of the Lewis Acid Zn(C6 F5 )2 Enables Organic Transistors with a Maximum Hole Mobility in Excess of 20 cm2 V-1 s-1., Adv Mater
Incorporating the molecular organic Lewis acid tris(pentafluorophenyl)borane [B(C6 F5 )3 ] into organic semiconductors has shown remarkable promise in recent years for controlling the operating characteristics and performance of various opto/electronic devices, including, light-emitting diodes, solar cells, and organic thin-film transistors (OTFTs). Despite the demonstrated potential, however, to date most of the work has been limited to B(C6 F5 )3 with the latter serving as the prototypical air-stable molecular Lewis acid system. Herein, the use of bis(pentafluorophenyl)zinc [Zn(C6 F5 )2 ] is reported as an alternative Lewis acid additive in high-hole-mobility OTFTs based on small-molecule:polymer blends comprising 2,7-dioctyl[1]benzothieno [3,2-b][1]benzothiophene and indacenodithiophene-benzothiadiazole. Systematic analysis of the materials and device characteristics supports the hypothesis that Zn(C6 F5 )2 acts simultaneously as a p-dopant and a microstructure modifier. It is proposed that it is the combination of these synergistic effects that leads to OTFTs with a maximum hole mobility value of 21.5 cm2 V-1 s-1 . The work not only highlights Zn(C6 F5 )2 as a promising new additive for next-generation optoelectronic devices, but also opens up new avenues in the search for high-mobility organic semiconductors.
Paterson AF, Mottram AD, Faber H, et al., 2019, Impact of the Gate Dielectric on Contact Resistance in High-Mobility Organic Transistors, Advanced Electronic Materials, Vol: 5
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The impact of the gate dielectric on contact resistance in organic thin-film transistors (OTFTs) is investigated using electrical characterization, bias-stress stability measurements, and bandgap density of states (DOS) analysis. Two similar dielectric materials, namely Cytop and poly[4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole-co-tetrafluoroethylene] (Teflon AF2400), are tested in top-gate bottom-contact OTFTs. The contact resistance of Cytop-based OTFTs is found to be greater than that of the AF2400-based devices, even though the metal/OSC interface remains identical in both systems. The Cytop devices are also found to perform worse in bias-stress stability tests which, along with the DOS calculations, suggests that charge trapping at the OSC/dielectric interface is more prevalent with Cytop than AF2400. This increased charge trapping at the Cytop OSC/dielectric interface appears to be associated with the higher contact resistance in Cytop OTFTs. Differences in the molecular structure between Cytop and AF2400 and the large difference in the glass transition temperature of the two polymers may be responsible for the observed difference in the transistor performance. Overall, this study highlights the importance of the gate dielectric material in the quest for better performing OTFTs and integrated circuits.
Ye L, Xiong Y, Chen Z, et al., 2019, Sequential Deposition of Organic Films with Eco-Compatible Solvents Improves Performance and Enables Over 12%-Efficiency Nonfullerene Solar Cells, ADVANCED MATERIALS, Vol: 31, ISSN: 0935-9648
Green JP, Cha H, Shahid M, et al., 2019, Dithieno[3,2-b:2',3'-d]arsole-containing conjugated polymers in organic photovoltaic devices., Dalton Trans
Arsole-derived conjugated polymers are a relatively new class of materials in the field of organic electronics. Herein, we report the synthesis of two new donor polymers containing fused dithieno[3,2-b:2',3'-d]arsole units and report their application in bulk heterojunction solar cells for the first time. Devices based upon blends with PC71BM display high open circuit voltages around 0.9 V and demonstrate power conversion efficiencies around 4%.
Eisner FD, Azzouzi M, Fei Z, et al., 2019, Hybridization of Local Exciton and Charge-Transfer States Reduces Nonradiative Voltage Losses in Organic Solar Cells, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, Vol: 141, Pages: 6362-6374, ISSN: 0002-7863
He Q, Shahid M, Panidi J, et al., A versatile star-shaped organic semiconductor based on benzodithiophene and diketopyrrolopyrrole, Journal of Materials Chemistry C, ISSN: 2050-7526
<p>A novel star-shaped π-conjugated oligomer containing a benzodithiophene core and four diketopyrrolopyrrole arms is reported.</p>
Reichsoellner E, Creamer A, Cong S, et al., 2019, Fast and Selective Post-polymerization Modification of Conjugated Polymers Using Dimethyldioxirane, FRONTIERS IN CHEMISTRY, Vol: 7, ISSN: 2296-2646
Sun G, Shahid M, Fei Z, et al., 2019, Highly-efficient semi-transparent organic solar cells utilising non-fullerene acceptors with optimised multilayer MoO3/Ag/MoO3 electrodes, MATERIALS CHEMISTRY FRONTIERS, Vol: 3, Pages: 450-455
Rimmele M, Ableidinger K, Marsh AV, et al., 2019, Thioalkyl- and sulfone-substituted poly(p-phenylene vinylene)s, POLYMER CHEMISTRY, Vol: 10, Pages: 738-750, ISSN: 1759-9954
Reichsöllner E, Creamer A, Cong S, et al., 2019, Fast and Selective Post-Polymerization Modification of Conjugated Polymers Using Dimethyldioxirane
Modification of functional groups attached to conjugated polymer backbones can drastically alter the material properties. Oxidation of electron-donating thioalkyl substituents to electron-withdrawing sulfoxides or sulfones is a particularly effective modification. However, so far, this reaction has not been studied for the modification of conjugated polymers used in organic electronics. Crucial questions regarding selectivity and reaction time waited to be addressed. Here, we show that the reaction is highly selective and complete within just a few minutes when using dimethyldioxirane (DMDO) for the oxidation of thioalkyl substituents attached to the well investigated conjugated polymers poly(9-(1-octylnonyl)carbazole-alt-4,7-dithienylbenzothiadiazole) (PCDTBT) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT). The selectivity was confirmed by comparison with polymers obtained from pre-oxidized monomers and by control experiments using related polymers without thioalkyl substituents. Using DMDO, the oxidation yields acetone as the only side-product, which reduces the work-up to mere evaporation of solvents and excessive reagent. Our results show that this oxidation is an exciting method for the preparation of electron-deficient conjugated polymers. It may even allow the preparation of electron acceptors for solar cells directly from the electron donors.
Krauspe P, Tsokkou D, Causa M, et al., 2018, Terahertz short-range mobilities in neat and intermixed regions of polymer: fullerene blends with controlled phase morphology, JOURNAL OF MATERIALS CHEMISTRY A, Vol: 6, Pages: 22301-22309, ISSN: 2050-7488
Rimmele M, Ableidinger K, Marsh A, et al., 2018, Thioalkyl- and Sulfone-Substituted Poly(p-Phenylene Vinylene)s
Poly(p-phenylene vinylene)s (PPVs) have been studied for decades, but research on this interesting class of conjugated polymers is far from being completed. New applications like in bioimaging keep emerging and even simple structural variations are still waiting to be explored. Surprisingly, not even dithioalkyl-substituted PPVs (S-PPVs) have been reported in the peer-reviewed literature, although the corresponding dialkoxy-substituted PPVs (O-PPVs) like MEH-PPV or MDMO-PPV are most frequently used and although thioalkyl substituents can improve the material properties significantly. We herein report the development of a highly efficient, scalable two-step synthesis of Gilch monomers for S-PPVs starting from low-cost 1,4-diiodobenzene. A low-temperature polymerization protocol has been developed for these monomers, affording high-molecular weight S-PPVs in excellent yields. The thermal, electrochemical, and photophysical properties of S-PPVs are reported to highlight the potential of these polymers. Furthermore, treatment with dimethyldioxirane is demonstrated to result in rapid conversion into sulfone-substituted PPVs (SO<sub>2</sub>-PPVs), introducing a route to high-molecular weight SO<sub>2</sub>-PPVs with exceptional stability and solid-state photoluminescence quantum yields of up to 0.46.
Boufflet P, Bovo G, Occhi L, et al., 2018, The Influence of Backbone Fluorination on the Dielectric Constant of Conjugated Polythiophenes, ADVANCED ELECTRONIC MATERIALS, Vol: 4, ISSN: 2199-160X
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- Citations: 2
Paterson AF, Lin Y-H, Mottram AD, et al., 2018, The Impact of Molecular p-Doping on Charge Transport in High-Mobility Small-Molecule/Polymer Blend Organic Transistors, ADVANCED ELECTRONIC MATERIALS, Vol: 4, ISSN: 2199-160X
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- Citations: 9
Paterson AF, Singh S, Fallon KJ, et al., 2018, Recent Progress in High-Mobility Organic Transistors: A Reality Check, ADVANCED MATERIALS, Vol: 30, ISSN: 0935-9648
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- Citations: 28
Patra D, Lee J, Dey S, et al., 2018, Chalcogen Bridged Thieno- and Selenopheno[2,3-d:5,4-d ']bisthiazole and Their Diketopyrrolopyrrole Based Low-Bandgap Copolymers, MACROMOLECULES, Vol: 51, Pages: 6076-6084, ISSN: 0024-9297
Marsh AV, Cheetham NJ, Little M, et al., 2018, Carborane-Induced Excimer Emission of Severely Twisted Bis-o-Carboranyl Chrysene, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, Vol: 57, Pages: 10640-10645, ISSN: 1433-7851
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- Citations: 6
Creamer A, Wood CS, Howes PD, et al., 2018, Post-polymerisation functionalisation of conjugated polymer backbones and its application in multifunctional emissive nanoparticles, NATURE COMMUNICATIONS, Vol: 9, ISSN: 2041-1723
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- Citations: 2
Rodriquez D, Kohl JG, Morel P, et al., 2018, Measurement of Cohesion and Adhesion of Semiconducting Polymers by Scratch Testing: Effect of Side-Chain Length and Degree of Polymerization, ACS MACRO LETTERS, Vol: 7, Pages: 1003-1009, ISSN: 2161-1653
Nieuwendaal RC, DeLongchamp DM, Richter LJ, et al., 2018, Characterization of Interfacial Structure in Polymer-Fullerene Bulk Heterojunctions via C-13 {H-2} Rotational Echo Double Resonance NMR, PHYSICAL REVIEW LETTERS, Vol: 121, ISSN: 0031-9007
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- Citations: 1
Eisner F, Seitkhan A, Han Y, et al., 2018, Solution-Processed In2O3/ZnO Heterojunction Electron Transport Layers for Efficient Organic Bulk Heterojunction and Inorganic Colloidal Quantum-Dot Solar Cells, SOLAR RRL, Vol: 2, ISSN: 2367-198X
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- Citations: 4
Datko BD, Walwark DJ, Fei Z, et al., 2018, Resolving Anomalous Heavy Atom Effects from Discrete Triplet Mediated Photochemistry Events on Single Conjugated Polymer Chains, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 122, Pages: 9718-9725, ISSN: 1932-7447
Squeo BM, Gregoriou VG, Han Y, et al., 2018, alpha,beta-Unsubstituted meso-positioning thienyl BODIPY: a promising electron deficient building block for the development of near infrared (NIR) p-type donor-acceptor (D-A) conjugated polymers, JOURNAL OF MATERIALS CHEMISTRY C, Vol: 6, Pages: 4030-4040, ISSN: 2050-7526
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- Citations: 2
Taroni PJ, Santagiuliana G, Wan K, et al., 2018, Toward Stretchable Self-Powered Sensors Based on the Thermoelectric Response of PEDOT:PSS/Polyurethane Blends, ADVANCED FUNCTIONAL MATERIALS, Vol: 28, ISSN: 1616-301X
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- Citations: 14
Wijeyasinghe N, Tsetseris L, Regoutz A, et al., 2018, Copper (I) Selenocyanate (CuSeCN) as a Novel Hole-Transport Layer for Transistors, Organic Solar Cells, and Light-Emitting Diodes, ADVANCED FUNCTIONAL MATERIALS, Vol: 28, ISSN: 1616-301X
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- Citations: 2
Datko B, Fei Z, Heeney M, et al., 2018, Effect of conformational changes on triplet formation in a heavy heteroatom conjugated polymer: Single polymer molecules and molecular aggregates, 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
Charlton RJ, Fogarty RM, Bogatko S, et al., 2018, Implicit and explicit host effects on excitons in pentacene derivatives, JOURNAL OF CHEMICAL PHYSICS, Vol: 148, ISSN: 0021-9606
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- Citations: 1
Fei Z, Eisner FD, Jiao X, et al., 2018, An Alkylated Indacenodithieno[3,2-b]thiophene-Based Nonfullerene Acceptor with High Crystallinity Exhibiting Single Junction Solar Cell Efficiencies Greater than 13% with Low Voltage Losses, ADVANCED MATERIALS, Vol: 30, ISSN: 0935-9648
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- Citations: 159
Lu R, Han Y, Zhang W, et al., 2018, Alkylated indacenodithieno[3,2-b] thiophene-based all donor ladder-type conjugated polymers for organic thin film transistors, Journal of Materials Chemistry C, Vol: 6, Pages: 2004-2009, ISSN: 2050-7534
We report the synthesis of a series of indacenodithieno[3,2-b]thiophene (IDTT) based conjugated polymers by copolymerization with three different electron rich co-monomers [thiophene (T), thieno[3,2-b] thiophene (TT) and dithieno[3,2-b:2′,3′-d]thiophene (DTT)] under Stille coupling conditions. The resulting all-donor polymers show very good solubility in common solvents and exhibit similar optical, thermal and electronic properties. However, the performance of these semiconductors in thin film transistor devices varied and was highly dependent on the nature of the co-monomer. All polymers exhibited unipolar p-type charge transport behaviour, with the mobility values following the trend of IDTT-TT > IDTT-DTT > IDTT-T. The peak saturation mobility value of IDTT-TT was extracted to be 1.1 cm 2 V -1 s -1 , amongst the highest mobility for all-donor conjugated polymers reported to date.
Panidi J, Paterson AF, Khim D, et al., 2018, Remarkable Enhancement of the Hole Mobility in Several Organic Small-Molecules, Polymers, and Small-Molecule:Polymer Blend Transistors by Simple Admixing of the Lewis Acid p-Dopant B(C6F5)(3), ADVANCED SCIENCE, Vol: 5, ISSN: 2198-3844
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- Citations: 10
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