A stable solution-processed polymer semiconductor with record high-mobility for printed transistors.

Microelectronic circuits/arrays produced via high-speed printing instead of traditional photolithographic processes offer an appealing approach to creating the long-sought after, low-cost, large-area flexible electronics. Foremost among critical enablers to propel this paradigm shift in manufacturing is a stable, solution-processable, high-performance semiconductor for printing functionally capable thin-film transistors - fundamental building blocks of microelectronics. We report herein the processing and optimisation of solution-processable polymer semiconductors for thin-film transistors, demonstrating very high field-effect mobility, high on/off ratio, and excellent shelf-life and operating stabilities under ambient conditions. Exceptionally high-gain inverters and functional ring oscillator devices on flexible substrates have been demonstrated. This optimised polymer semiconductor represents a significant progress in semiconductor development, dispelling prevalent skepticism surrounding practical usability of organic semiconductors for high-performance microelectronic devices, opening up application opportunities hitherto functionally or economically inaccessible with silicon technologies, and providing an excellent structural framework for fundamental studies of charge transport in organic systems.

O,O'-Disubstituted N,N'-dihydroxynaphthalenediimides (DHNDI): first principles designed organic building blocks for materials science.

N,N'-Disubstituted naphthalenediimides (NDIs), planar, electron-deficient building blocks, play an important role in materials and biological sciences. Naphthalene core substituents control the HOMO and LUMO energies, whereas the N-alkyl or aryl substituents affect the solubility, aggregation, and packing propensity in condensed phases. N,N'-Dihydroxynaphthalenediimide (DHNDI) allows expanding the chemical diversity by O-alkylation, acylation, or sulfonylation; these derivatives also allow fine-tuning of the HOMO/LUMO levels. The synthesis, UV-vis, electrochemical, solid state, and computational prediction of the properties of such derivatives are presented.

A random copolymer based on dithienothiophene and diketopyrrolopyrrole units for high performance organic solar cells.

A random donor-acceptor semiconducting copolymer based on diketopyrrolopyrrole as the acceptor unit and dithienothiophene as the donor unit has been synthesized and characterized. Preliminary studies of BHJ solar cells based on this polymer with PC(71)BM showed a high PCE of above 5% under 100 mW cm(-2) AM1.5 solar illumination.

Polymer solar cells based on copolymers of dithieno[3,2-b:2',3'-d]silole and thienopyrroledione.

Novel low band gap copolymers based on dithienosilole and thienopyrroledione units were synthesized. Copolymer P1 with branched side chains on the TPD units demonstrated a PCE of 4.4% with a high V(oc) of 0.89 V for OPV applications while OTFT devices fabricated from a copolymer containing linear side chains (P2) performed better in OTFT device configurations.