title: Enhanced mobility and effective control of threshold voltage in P3HT-based field-effect transistors via inclusion of oligothiophenes.
abstract: Improved organic field-effect transistor (OFET) performance through a polymer-oligomer semiconductor blend approach is demonstrated. Incorporation of 2,5-bis(3-dodecylthiophen-2-yl)thieno[3,2-b]thiophene (BTTT) into poly(3-hexylthiophene) (P3HT) thin films leads to approximately a 5-fold increase in charge carrier mobility, a 10-fold increase in current on-off ratio, and concomitantly, a decreased threshold voltage to as low as 1.7 V in comparison to single component thin films. The blend approach required no pre- and/or post treatments, and processing was conducted under ambient conditions. The correlation of crystallinity, surface morphology and photophysical properties of the blend thin films was systematically investigated via X-ray diffraction, atomic force microscopy and optical absorption measurements respectively, as a function of blend composition. The dependence of thin-film morphology on the blend composition is illustrated for the P3HT:BTTT system. The blend approach provides an alternative avenue to combine the advantageous properties of conjugated polymers and oligomers for optimized semiconductor performance.
authors.affiliation: †School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332-0100, United States.
authors.forename: Ping-Hsun
authors.initials: PH
authors.lastname: Chu
authors.affiliation: ‡Department of Polymer Science and Engineering, Conte Research Center, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01002, United States.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: ‡Department of Polymer Science and Engineering, Conte Research Center, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01002, United States.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Colella
authors.affiliation: †School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332-0100, United States.
authors.forename: Boyi
authors.initials: B
authors.lastname: Fu
authors.affiliation: §School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States.
authors.forename: Jung Ok
authors.initials: JO
authors.lastname: Park
authors.affiliation: §School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States.|∥School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332-0400, United States.
authors.forename: Mohan
authors.initials: M
authors.lastname: Srinivasarao
authors.affiliation: ‡Department of Polymer Science and Engineering, Conte Research Center, University of Massachusetts, 120 Governors Drive, Amherst, Massachusetts 01002, United States.
authors.forename: Alejandro L
authors.initials: AL
authors.lastname: Briseño
authors.affiliation: †School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332-0100, United States.|§School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States.|∥School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332-0400, United States.
authors.forename: Elsa
authors.initials: E
authors.lastname: Reichmanis
keywords: charge transport; organic field effect transistors; poly(3-hexylthiophene); polymer-oligomer blend; threshold voltage