Donor–Acceptor Conjugated Polymers Based on Dithieno[3,2-b:3′,2′-b′]naphtho[1,2-b:5,6-b′]dithiophene: Synthesis and Semiconducting Properties

π-Conjugation expanded isoindigo derivatives and the donor-acceptor conjugated polymers: synthesis and characterization

Two π-conjugation expanded isoindigo derivatives (DIID-PhCO and TIID-PhCO) composed of up to 18 rings and two donor-acceptor conjugated polymers based on DIID-PhCO were synthesized. Both polymers are ambipolar semiconductors with balanced hole and electron mobilities up to 0.10 and 0.14 cm² V^-1 s^-1, respectively, under ambient conditions.

Cyano-substituted benzochalcogenadiazole-based polymer semiconductors for balanced ambipolar organic thin-film transistors

Two new cyano-substituted benzochalcogenadiazoles were copolymerized with bithiophene, and the polymers show well balanced ambipolarity in transistors.

Alkylated Selenophene-Based Ladder-Type Monomers via a Facile Route for High-Performance Thin-Film Transistor Applications

We report the synthesis of two new selenophene-containing ladder-type monomers, cyclopentadiselenophene (CPDS) and indacenodiselenophene (IDSe), via a 2-fold and 4-fold Pd-catalyzed coupling with a 1,1-diborylmethane derivative. Copolymers with benzothiadiazole were prepared in high yield by Suzuki polymerization to afford materials which exhibited excellent solubility in a range of nonchlorinated solvents. The CPDS copolymer exhibited a band gap of just 1.18 eV, which is among the lowest reported for donor-acceptor polymers. Thin-film transistors were fabricated using environmentally benign, nonchlorinated solvents, with the CPDS and IDSe copolymers exhibiting hole mobility up to 0.15 and 6.4 cm² V^-1 s^-1, respectively. This high performance was achieved without the undesirable peak in mobility often observed at low gate voltages due to parasitic contact resistance.

Hole Mobility and Electron Injection Properties of D-A Conjugated Copolymers with Fluorinated Phenylene Acceptor Units

A novel wide-gap conjugated polymer PhF2,5 (E_g = 1.9 eV) is designed to contain alternating cyclopentadithiophene and difluorophenylene unit with the goal of favoring unipolar organic field effect transistor characteristics. The higher lowest unoccupied molecular orbital energy of PhF2,5 increases the barrier to electron injection, leading to unipolar transport and higher on/off ratios, without sacrificing desirable high hole mobilities.

Synthesis and characterization of acceptor–donor–acceptor-based low band gap small molecules containing benzoselenadiazole

Acceptor–donor–acceptor-type compounds 5′,5″-(benzo[c][1,2,5]selenadiazole-4,7-diyl)bis(3′-dodecyl-2,2′-bithiophene-5-carbonitrile) (9) and 4,4′-(5,5′-(benzo[c][1,2,5]selenadiazole-4,7-diyl)bis(3-dodecylthiophene-5,2-diyl))dibenzonitrile (10) were designed and synthesized. These compounds differ in terminal positions, compound 9 with a thiophene-containing nitrile group and compound 10 with a phenyl-containing nitrile group. Both compounds have shown good thermal stability and low band gap. The band gaps of compounds 9 and 10 were 1.74 and 1.83 eV, respectively. These results indicate that they are promising materials for use in optoelectronics.