Pentacene (1) is a polyaromatic hydrocarbon consisting of five linearly condensed benzene rings. 1 has attracted much attention as an electronic devices materials in recent years, especially, in the field of p-type semiconductor research. Correspondingly, C₆₀ is known as an n-type semiconductor, and both of it and 1 have been actively studied as a transistor consisting only of organic and molecular substance. 1 for use in such applications must be of extremely high purity. TCI offers 1 purified to a suitable standard by recrystallization and sublimation.

Additionally, Takimiya et al. have developed 2,7-diphenyl[1]benzothieno[3,2-b][1]benzothiophene (2) which includes chalcogen atoms in a molecule. They prepared thin film devices using 2 on silicon substrates by vacuum deposition, and measured their semiconducting properties (Fig.1). According to their results, the field-effect mobility of the device is very high (0.19-2.0cm²/Vs), and indicates a high value comparable as pentacene (0.5-3.0cm²/Vs). Moreover, the on-off current ratios were as high as 10⁷, and the semiconducting properties were maintained for over 100 days.

It is expected that these types of organic semiconducting materials will significantly advance the field of electronic devices applied research.

C₆₀ & C₇₀