Design strategy for air-stable organic semiconductors applicable to high-performance field-effect transistors
Kazuo Takimiya et al
- Publisher: Taylor & Francis Group
Science and Technology of Advanced Materials
(issn: 1468-6996, eissn: 1878-5514)
Materials of engineering and construction. Mechanics of materials | TA401-492 | Biotechnology | TP248.13-248.65
Electronic structure of air-stable, high-performance organic field-effect transistor (OFET) material, 2,7-dipheneylbenzothieno[3,2-b]benzothiophene (DPh-BTBT), was discussed based on the molecular orbital calculations. It was suggested that the stability is originated from relatively low-lying HOMO level, despite the fact that the molecule contains highly π-extended aromatic core (benzothieno[3,2-b]benzothiophene, BTBT) with four fused aromatic rings like naphthacene. This is rationalized by the consideration that the BTBT core is not isoelectronic with naphthacene but with chrysene, a cata-condensed phene with four benzene rings. It is well known that the acene-type compound is unstable among its structural isomers with the same number of benzene rings. Therefore, polycyclic aromatic compounds possessing the phene-substructure will be good candidates for stable organic semiconductors. Considering synthetic easiness, we suggest that the BTBT-substructure is the molecular structure of choice for developing air-stable organic semiconductors.