title: Understanding the Crystal Packing and Organic Thin-Film Transistor Performance in Isomeric Guest-Host Systems.
abstract: In order to understand how additives influence the structure and electrical properties of active layers in thin-film devices, a compositionally identical but structurally different guest-host system based on the syn and anti isomers of triethylsilylethynyl anthradithiophene (TES ADT) is systematically explored. The mobility of organic thin-film transistors (OTFTs) comprising anti TES ADT drops with the addition of only 0.01% of the syn isomer and is pinned at the mobility of OTFTs having pure syn isomer after the addition of only 10% of the isomer. As the syn isomer fraction increases, intermolecular repulsion increases, resulting in a decrease in the unit-cell density and concomitant disordering of the charge-transport pathway. This molecular disorder leads to an increase in charge trapping, causing the mobility of OTFTs to drop with increasing syn-isomer concentration. Since charge transport is sensitive to even minute fractions of molecular disorder, this work emphasizes the importance of prioritizing structural compatibility when choosing material pairs for guest-host systems.
authors.affiliation: Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Hailey
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Petty
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Washbourne
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
authors.forename: Karl J
authors.initials: KJ
authors.lastname: Thorley
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
authors.forename: Sean R
authors.initials: SR
authors.lastname: Parkin
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Anthony
authors.affiliation: Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.|Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ, 08544, USA.
authors.forename: Yueh-Lin
authors.identifier: http://orcid.org/0000-0002-4284-0847
authors.initials: YL
authors.lastname: Loo
keywords: disorder; guest-host systems; isomers; organic semiconductors; organic thin-film transistors