Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
CPP 56.3: Vortrag
Mittwoch, 18. März 2020, 10:15–10:30, ZEU 222
Favored face-on crystal orientation in poly(3-(6-bromohexyl)-thiophene) on graphene as a result of modified interfacial interactions — •Oleksandr Dolynchuk1, Philip Schmode2, Matthias Fischer1, Mukundan Thelakkat2, and Thomas Thurn-Albrecht1 — 1Experimental Polymer Physics, Martin Luther University Halle-Wittenberg, Germany — 2Applied Functional Polymers, University of Bayreuth, Germany
Directed crystallization on a substrate could be advantageous for inducing molecular orientation in semicrystalline conjugated polymers whose charge transport properties are anisotropic. Although a preferred face-one molecular orientation was shown in monolayers of poly(3-hexylthiophene) (P3HT) on graphite, a full face-one orientation in thicker P3HT films has not been realized so far. We assume that it is a result of two competing interfacial orientations initiated at the interfaces to vacuum and graphite. Here it is shown that modification of the chemical structure of P3HT side chains can alter the surface interactions and result in fully face-on oriented crystals. Specifically, we present a comparative study of the substrate induced orientation in thin films of poly(3-(6-bromohexyl)-thiophene) (P3BrHT) and P3HT on graphene. The crystal orientation in films of both polymers was explored by surface-sensitive grazing incidence XRD. The results indicated that P3BrHT on graphene had solely face-on oriented crystals in films up to 26 nm, whereas P3HT showed the mixed face-on and edge-on crystal orientation with edge-on crystals formed at the top surface that supports our assumption about competing interfacial orientations.