High-Performance Hole Transport and Quasi-Balanced Ambipolar OFETs Based on D–A–A Thieno-benzo-isoindigo Polymers

• Two new conjugated polymers are synthesized based on a novel donor–acceptor–acceptor (D–A–A) design strategy with the intention of attaining lower lowest unoccupied molecular obital levels compared to the normally used D–A strategy. By coupling two thieno-benzo-isoindigo units together via the phenyl position to give a new symmetric benzene-coupled di-thieno-benzo-isoindigo (BdiTBI) monomer as an A–A acceptor and thiophene (T) or bithiophene (2T) as a donor, two new polymers PT-BdiTBI and P2T-BdiTBI are synthesized via Stille coupling. The two polymers are tested in top gate and top contact field effect transistors, which exhibit balanced ambipolar charge transport properties with poly(methyl methacrylate) as dielectric and a high hole mobility up to 1.1 cm2 V–1 s–1 with poly(trifluoroethylene) as dielectric. The polymer films are investigated using atomic force microscopy, which shows fibrous features due to their high crystallinity as indicated by grazing incidence wide-angle X-ray scattering. The theoretical calculations agree well with the experimental data on the energy levels. It is demonstrated that the D–A–A strategy is very effective for designing low band gap polymers for organic electronic applications.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

NATURVETENSKAP  -- Kemi -- Teoretisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Theoretical Chemistry (hsv//eng)

NATURVETENSKAP  -- Kemi -- Polymerkemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Polymer Chemistry (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Nyckelord

ambipolar

conjugated polymers

donor–acceptor–acceptor strategy

high mobility

organic field effect transistors

conjugated polymers

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art (ämneskategori)

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