Dresden 2017 – wissenschaftliches Programm
CPP 9.6: Vortrag
Montag, 20. März 2017, 16:45–17:00, ZEU 260
UV-Vis-NIR spectroscopy studies on molecularly doped semiconducting polymers — •Malavika Arvind1, Patrick Pingel2, Silvia Janietz2, and Dieter Neher1 — 1University of Potsdam, Soft Matter Physics, Germany — 2Fraunhofer Institute for Applied Polymer Research, Potsdam, Germany
In recent years, significant efforts have been devoted towards understanding the fundamental processes involved in the doping of organic semiconductors with small molecules. Nevertheless, there is still a large degree of ambiguity in the field, which has prevented us from being able to truly exploit this method to better our organic devices. In this work, we utilize UV-Vis-NIR spectroscopy to study the sub-band gap optical transitions that occur in the well known semiconducting polymer poly(3-hexylthiophene) (P3HT) when doped with tris(pentafluorophenyl)borane (BCF), a strong Lewis acid, and compare it to the more commonly studied p-dopant, tetrafluorotetracyanoquinodimethane (F4TCNQ). In spite of the dissimilarity in their structures, both dopants are found to efficiently create positive polarons in P3HT, in solutions as well as in films. Here we investigate the influence of various parameters such as polymer/dopant concentration, solvent, temperature on the nature and efficiency of molecular doping, and also address the question of whether pre-aggregation of the polymer in solution assists or suppresses polaron-formation in P3HT.