Thienothiophene-benzotriazole-based semicrystalline linear copolymers for organic field effect transistors

A series of thienothiophene-benzotriazole-based semicrystalline copolymers, PTTBTz, PTTBTz-F, and PTTBTz-OR, were synthesized by considering chain linearity, planarity and inter-chain packing by virtue of non-covalent attractive interaction. Fluorine and alkoxy substituents were introduced to modulate the intra- and inter-chain coulombic interactions and crystalline ordering. The fluorine and alkoxy-substituted PTTBTz-F and PTTBTz-OR showed pronounced inter-chain packing with edge-on orientation confirmed by UV-vis absorption and X-ray diffraction measurements. The well-resolved diffraction patterns were obtained for PTTBTz-F and PTTBTz-OR, showing (100)similar to(500) inter-lamellar scattering peaks (d-spacing, 17 similar to 18 angstrom) in the out-of-plane direction and a pi-pi stacking peak (d-spacing, 3.5 similar to 4.1 angstrom) in the in-plane direction. Organic field effect transistor (OFET) devices were fabricated with a bottom gate and top contact geometry. PTTBTz-F (mu(h) = 4.49 x 10(-2) cm(2) V-1 s(-1), on/off ratio = 1.13 x 107) and PTTBTz-OR (mu(h) = 8.39 x 10(-3) cm(2) V-1 s(-1), on/off ratio = 2.98 x 104) showed nearly 3 and 2 orders of magnitude higher hole mobility upon annealing at 305 and 260 degrees C, with compared to the unsubstituted PTTBTz.X1165Ysciescopu

Boronic acids for sensing and other applications - a mini-review of papers published in 2013

Boronic acids are increasingly utilised in diverse areas of research. Including the interactions of boronic acids with diols and strong Lewis bases as fluoride or cyanide anions, which leads to their utility in various sensing applications. The sensing applications can be homogeneous assays or heterogeneous detection. Detection can be at the interface of the sensing material or within the bulk sample. Furthermore, the key interaction of boronic acids with diols allows utilisation in various areas ranging from biological labelling, protein manipulation and modification, separation and the development of therapeutics. All the above uses and applications are covered by this mini-review of papers published during 2013

Benzotriazole-Containing Planar Conjugated Polymers with Noncovalent Conformational Locks for Thermally Stable and Efficient Polymer Field-Effect Transistors

We report a series of benzotriazole-based semicrystalline pi-conjugated polymers with noncovalent conformational locks for applications in polymer field-effect transistors. The benzotriazole moiety is a versatile electron-deficient building block that offers two chemically functionalizable sites, 2(N) and 5, 6(C) positions,. allowing easy modulation of the solution processability and electronic structures of the resulting polymers. Fluorine or alkoxy substituents were introduced to the benzotriazole unit to enhance the molecular ordering through intra- and intermolecular F center dot center dot center dot S, F center dot center dot center dot H-C, C-F center dot center dot center dot pi(F), or S center dot center dot center dot O attractive interactions. The fluorinated polymer (PTBTz-F) showed remarkably enhanced hole mobility (mu(h) = 1.9 cm(2)/(V.S), on/off ratio = 8 x 10(7)) upon thermal annealing at 305 degrees C, compared to the unsubstituted one (PTBTz) (mu(h) = 7.0 x 10(-3) cm(2)/(V.s), on/off ratio = 3 x 10(6)). Alkoxy unit substitution (PTBTz-OR) also improved the carrier mobility up to 0.019 cm(2)/(V.s) with an on/off ratio of 4 x 10(5). Fluorine or alkoxy substitution induced tight interchain ordering with edge-on orientation, as confirmed by X-ray diffraction measurements. In particular, fluorinated PTBTz-F showed high thermal stability (T-d 453 degrees C) and the remarkable device characteristics with deep frontier orbital levels.X1110083sciescopu

Life test sampling plans for Weibull distributed lifetimes under accelerated hybrid censoring

Life test sampling plan, Hybrid censoring, Producer risk, Consumer risk, Acceleration factor, 62N05,