title: Polarity and air-stability transitions in field-effect transistors based on fullerenes with different solubilizing groups.
abstract: A series of o-xylene and indene fullerene derivatives with varying frontier molecular orbital energy levels were utilized for assessing the impact of the number of solubilizing groups on the electrical performance of fullerene-based organic-field-effect transistors (OFETs). The charge-carrier polarity was found to be strongly dependent upon the energy levels of fullerene derivatives. The o-xylene C60 monoadduct (OXCMA) and indene C60 monoadduct (ICMA) exhibited unipolar n-channel behaviors with high electron mobilities, whereas the bis- and trisadducts of indene and o-xylene C60 derivatives showed ambipolar charge transport. The OXCMA OFETs fabricated by solution shearing and molecular n-type doping showed an electron mobility of up to 2.28 cm(2) V(-1) s(-1), which is one of the highest electron mobilities obtained from solution-processed fullerene thin-film devices. Our findings systematically demonstrate the relationship between the energy level and charge-carrier polarity and provide insight into molecular design and processing strategies toward high-performance fullerene-based OFETs.
authors.affiliation: School of Nano-Bioscience & Chemical Engineering, KIER-UNIST Advanced Center for Energy, Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea.
authors.forename: Hojeong
authors.initials: H
authors.lastname: Yu
authors.forename: Han-Hee
authors.initials: HH
authors.lastname: Cho
authors.forename: Chul-Hee
authors.initials: CH
authors.lastname: Cho
authors.forename: Ki-Hyun
authors.initials: KH
authors.lastname: Kim
authors.forename: Dong Yeong
authors.initials: DY
authors.lastname: Kim
authors.forename: Bumjoon J
authors.initials: BJ
authors.lastname: Kim
authors.forename: Joon Hak
authors.initials: JH
authors.lastname: Oh