title: Nanomorphology-driven two-stage hole mobility in blend films of regioregular and regiorandom polythiophenes.
abstract: We report the nanomorphology-driven two-stage hole mobility in the blend films of regioregular and regiorandom poly(3-hexylthiophene) (P3HT) polymers of which regioregularity was 92.2% and 33.0%, respectively. The hole mobility of blend films was measured by employing a top-contact type organic field-effect transistor which has an aromatic polyimide gate insulating layer and silver source/drain electrodes. Results showed that the hole mobility of blend films was suddenly reduced as large as two orders of magnitude as the bulk regioregularity of blend films decreased from 89.8% to 86.3%, even though the hole mobility change was far less than one order of magnitude after and before this boundary condition. The discontinuous two-stage hole mobility trend has been attributed to the destruction of P3HT chain ordering/alignment in the blend films at the boundary blend composition, as evidenced from the huge changes in optical absorption coefficient, surface nanomorphology, and in-plane/out-of-plane nanostructures in the blend films.
authors: Organic Nanoelectronics Laboratory, Department of Chemical Engineering, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors: Sungho
authors: S
authors: Nam
authors: Seungsoo
authors: S
authors: Lee
authors: Inhyuk
authors: I
authors: Lee
authors: Minjung
authors: M
authors: Shin
authors: Hwajeong
authors: H
authors: Kim
authors: Youngkyoo
authors: Y
authors: Kim
mesh_terms: D004566:Electrodes; D037741:Fullerenes / Q000737:chemistry; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013237:Stereoisomerism; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D013876:Thiophenes; C507295:poly(3-hexylthiophene); C530172:pristine (C60); D012834:Silver