title: Anomalous pressure effect in heteroacene organic field-effect transistors.
abstract: Anomalous pressure dependent conductivity is revealed for heteroacene organic field-effect transistors of dinaphtho[2, 3-b:2', 3'-f]thieno[3, 2-b]thiophene single crystals in the direction of a and b crystallographic axes. In contrast to the normal characteristics of a monotonic increase in mobility μ with the application of external hydrostatic pressure P in conductors, we found that the present organic semiconductor devices exhibit nonmonotonic and gigantic pressure dependence including an even negative pressure coefficient dμ/dP. In combination with a structural analysis based on x-ray diffraction experiments under pressure, it is suggested that on-site molecular orientation and displacement peculiar in heteroacene molecules are responsible for the anomalous pressure effect.
authors.affiliation: ISIR, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan. ksakai@sanken.osaka-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Sakai
authors.forename: Y
authors.initials: Y
authors.lastname: Okada
authors.forename: S
authors.initials: S
authors.lastname: Kitaoka
authors.forename: J
authors.initials: J
authors.lastname: Tsurumi
authors.forename: Y
authors.initials: Y
authors.lastname: Ohishi
authors.forename: A
authors.initials: A
authors.lastname: Fujiwara
authors.forename: K
authors.initials: K
authors.lastname: Takimiya
authors.forename: J
authors.initials: J
authors.lastname: Takeya