- High-Performance Semiconducting Polythiophenes for Organic Thin-Film Transistors
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Conjugated polymers have been widely studied as potential semiconductor materials for organic thin-film transistors (TFTs). However, they have provided functionally poor transistor properties when the TFTs are fabricated in air. We have developed a class of liquid crystalline regioregular polythiophenes, PQTs, that possess sufficient air stability to enable achievement of excellent TFT properties under ambient conditions. These polythiophenes exhibit unique self-assembly ability and form highly structured thin films when deposited from solution under appropriate conditions. TFTs fabricated in air with PQT channel layers have provided high field-effect mobility to 0.14 cm2 V-1 s-1 and high current modulation to over 107, together with other desirable transistor properties. These high-performance polythiophenes will therefore help bring the long-standing concept of low-cost organic/polymer transistor circuits closer to commercial reality. Copyright
- Ong, Beng S.,Wu, Yiliang,Liu, Ping,Gardner, Sandra
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- Tetrathiafulvalene (TTF)-functionalized thiophene copolymerized with 3,3′-didodecylquaterthiophene: Synthesis, TTF trapping activity, and response to trinitrotoluene
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We report a synthesis route to a thiophene polymer where the repeat unit consists of 3,3′-didodecylquaterthiophene (as in PQT12) plus an additional thiophene ring from which other functional groups may be projected. The hydroxymethyl form of this polymer, while only a poor semiconductor in its own right, serves as a vehicle for compatibilizing PQT12 itself with arbitrary functional groups. In this article, we focus on tetrathiafulvalene (TTF) as the functionality. As expected, the TTF group acts as a hole trap, as shown by loss of hole mobility and a surprising negative Seebeck coefficient, but this enables a current-increase response to trinitrotoluene as an analyte and confirms a similar observation we recently reported for a dissolved TTF. Added dopants also fill the trap states, restoring hole mobility and the typical positive Seebeck coefficient.
- Sinha, Jasmine,Lee, Stephen J.,Kong, Hoyoul,Swift, Thomas W.,Katz, Howard E.
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- The influence of electron deficient unit and interdigitated packing shape of new polythiophene derivatives on organic thin-film transistors and photovoltaic cells
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A series of new polythiophene derivatives containing a thiazole ring as an electron deficient unit were successfully synthesized via Stille coupling reactions. Synthesized polymers were classified into two types (H-shape packing and A-shape packing) based on their interdigitated packing structure induced by different side chain configurations. The thiophene derivatives that contained a thiazole unit (PT50Tz50, PTz100, and PTTz) exhibited much better thermal stability than did the full thiophene polymers (PT100 and PTT). The polymers containing the thiazole unit (PTz100 and PTTz) showed a red-shifted absorption spectrum with clear vibronic structure. In addition, the XRD and AFM results showed that the polymers containing the thiazole unit and interdigitated H-shape exhibited much better ordered and connected intermolecular structures than did other polymers. The improved intermolecular ordering and surface morphologies directly facilitated charge carrier transport in thin film transistor (TFT) devices, without introducing charge traps, and yielded higher solar cell performance. Among these polymers, the PTTz copolymer exhibited the best TFT performance (μ = 0.050 cm2 V-1 s-1, on/off ratio = 106, and Vth = -2 V) and solar cell performance (PCE = 1.39%, Jsc = 6.58 mA cm-2, and Voc = 0.58 V).
- Kong, Hoyoul,Cho, Shinuk,Lee, Dong Hoon,Cho, Nam Sung,Park, Moo-Jin,Jung, In Hwan,Park, Jong-Hwa,Park, Chan Eon,Shim, Hong-Ku
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experimental part
p. 2886 - 2898
(2012/04/18)
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- SMALL MOLECULAR THIOPHENE COMPOUND
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A small molecular thiophene compound consisting of a plurality of thiophene units, each thiophene unit being represented by structure (A) wherein each thiophene unit is bonded at either or both of the second ring position and the fifth ring position, wher
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Page/Page column 11-12
(2008/12/04)
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- SMALL MOLECULAR THIOPHENE COMPOUND HAVING DIVALENT LINKAGE
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A small molecular thiophene compound consisting of: at least one divalent linkage; and a plurality of thiophene units, each thiophene unit being represented by structure (A) wherein each thiophene unit is bonded at either or both of the second ring positi
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Page/Page column 11-12
(2008/12/04)
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- Processes to prepare small molecular thiophene compounds
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A process composed of subjecting a reaction mixture comprising a reaction medium, a coupling agent, and a precursor to a coupling temperature to preferentially form a desired small molecular thiophene compound in a single-step synthesis, wherein the precu
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Page/Page column 11-12
(2008/06/13)
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- Coincidence of the Molecular Organization of β-Substituted Oligothiophenes in Two-Dimensional Layers and Three-Dimensional Crystals
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The molecular arrangements of three different alkyl-substituted oligothiophenes both in two-dimensional adsorbed layers at a substrate interface and in bulk three-dimensional crystals were studied. Scanning tunneling microscopy (STM) was used to investigate the ordering of the conjugated oligomers in two-dimensional layers adsorbed on graphite. These data were compared with the X-ray structure determinations of single crystals revealing the arrangement in the three-dimensional bulk material. Quaterthiophenes 1 and 2, bearing dodecyl and hexyl side chains, respectively, exhibit a lamella-type stacking of the conjugated backbone concomitant with an interlocking of the alkyl side chains both on the surface and in the crystal. In contrast, the arrangement of propyl-substituted quaterthiophene 3 is rather "herringbone-like" due to the reduced interactions of the shorter alkyl side chains. In all three cases, evidently, the two-dimensional ordering at the graphite surface is coincident with the molecular packing in one cross-section of the three-dimensional crystal.
- Azumi, Reiko,Goetz, Guenther,Debaerdemaeker, Tony,Baeuerle, Peter
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p. 735 - 744
(2007/10/03)
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- Oligothiophene - immer laenger? Synthese, Charakterisierung und rastertunnelmikroskopische Abbildung von homologen, isomerenreinen Oligo(alkylthiophenen)
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Stichworte: Cyclovoltammetrie * Oligothiophene * Rastertunnelmikroskopie * Thiophene
- Baeuerle, Peter,Fischer, Thomas,Bidlingmeier, Bernd,Stabel, Andreas,Rabe, Juergen P.
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p. 335 - 339
(2007/10/02)
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