title: Morphology-dependent electronic properties in cross-linked (P3HT-b-P3MT) block copolymer nanostructures.
abstract: Combined Kelvin probe force microscopy and wavelength-resolved photoluminescence measurements on individual pre- and post-cross-linked poly(3-hexylthiophene)-b-poly(3-methyl alcohol thiophene) (P3HT-b-P3MT) nanofibers have revealed striking differences in their optical and electronic properties driven by structural perturbation of the crystalline aggregate nanofiber structures after cross-linking. Chemical cross-linking from diblock copolymer P3HT-b-P3MT using a hexamethylene diisocyanate cross-linker produces a variety of morphologies including very small nanowires, nanofiber bundles, nanoribbons, and sheets, whose relative abundance can be controlled by reaction time and cross-linker concentration. While the different cross-linked morphologies have almost identical photophysical characteristics, KPFM measurements show that the surface potential contrast, related to the work function of the sample, depends sensitively on nanostructure morphology related to chain-packing disorder.
authors.affiliation: Departments of Physics, ‡Polymer Science and Engineering, and §Chemistry, University of Massachusetts , Amherst, Massachusetts 01003, United States.
authors.forename: Mina
authors.initials: M
authors.lastname: Baghgar
authors.forename: Austin M
authors.initials: AM
authors.lastname: Barnes
authors.forename: Emily
authors.initials: E
authors.lastname: Pentzer
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Wise
authors.forename: Brenton A G
authors.initials: BA
authors.lastname: Hammer
authors.forename: Todd
authors.initials: T
authors.lastname: Emrick
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Dinsmore
authors.forename: Michael D
authors.initials: MD
authors.lastname: Barnes