Intramolecular Locked Dithioalkylbithiophene‐Based Semiconductors for High‐Performance Organic Field‐Effect Transistors

Abstract

New 3,3'-dithioalkyl-2,2'-bithiophene (SBT)-based small molecular and polymeric semiconductors are synthesized by end-capping or copolymerization with dithienothiophen-2-yl units. Single-crystal, molecular orbital computations, and optical/electrochemical data indicate that the SBT core is completely planar, likely via S(alkyl)⋯S(thiophene) intramolecular locks. Therefore, compared to semiconductors based on the conventional 3,3'-dialkyl-2,2'-bithiophene, the resulting SBT systems are planar (torsional angle <1°) and highly π-conjugated. Charge transport is investigated for solution-sheared films in field-effect transistors demonstrating that SBT can enable good semiconducting materials with hole mobilities ranging from ≈0.03 to 1.7 cm V s . Transport difference within this family is rationalized by film morphology, as accessed by grazing incidence X-ray diffraction experiments.

A Simple Phenyl Group Introduced at the Tail of Alkyl Side Chains of Small Molecular Acceptors: New Strategy to Balance the Crystallinity of Acceptors and Miscibility of Bulk Heterojunction Enabling Highly Efficient Organic Solar Cells

“…However, as pointed out above, the research of side chains of SMAs is monotonous and heavily dragged behind. Despite there have been tremendous and effective reports about the side chain modification of donor semiconductors, these results could be invalid even false in SMAs for their inherent distinction of molecular construction. For most of the donor materials, the main backbones were built by π–σ–π type with the electron‐rich, π‐spacers and electron‐deficient moieties connected by rotatable single bands.…”

“…The π–σ–π‐type backbones usually promise with good flexibility and weaker crystallinity of materials. Thus, the side chain engineering of donor materials mainly focuses on the enhancement of crystallinity and intermolecular interactions . While for SMAs, the plane of the molecular backbone is locked by the sp 3 carbon of the core and vinyl attached to the end caps.…”

Overcoming intra-molecular repulsions in PEDTT by sulphate counter-ion

“…Albeit attractive S-S interactions are known in literature, these are known in aliphatic, non-cyclic systems, where for steric reasons S-S non-covalent attractions are possible. (38)(39)(40) Therefore, we needed an external influence, such as the addition of an adequate counter-ion.…”

Ultraviolet Photodetecting and Plasmon-to-Electric Conversion of Controlled Inkjet-Printing Thin-Film Transistors

“…Over the past decade, field-effect transistors (FETs) and thin-film transistors (TFTs) based on organic and inorganic materials have been widely developed for advanced applications, such as flat-panel displays for realizing high-resolution displays. The advantages of TFTs based on metal-oxide-based materials include high electron mobility, thermal stability and stable electrical characteristics [1][2][3][4][5][6]. Recently, solution processing methods under low temperatures of 200-300 • C have attracted much interest for fabricating metal-oxide-based TFTs.…”