Berlin 2012 – wissenschaftliches Programm
DS 44: Poster IV: Thin film photovoltaics; Organic electronics and photovoltaics (jointly with CPP, HL, O); Organic thin films; Trends in atomic layer deposition (Focused session)
DS 44.31: Poster
Freitag, 30. März 2012, 09:30–12:00, Poster E
Study of excited states and a model for exciton-polaron interaction in P3HT — •Shine Philip1, Klaus Müller1, Matthias Richter1, Marinus Kunst2, and Dieter Schmeißer1 — 1Brandenburgische Technische Universität Cottbus, Angewandte Physik-Sensorik, 03046 Cottbus, Germany — 2Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe (E-I6), Hahn-Meitner-Platz 1, 14109 Berlin, Germany
Organic semiconductors efficiently harvest light in the region of the solar spectrum due to a high absorption/extinction coefficient.In our work we study the electronic structure and the charge carrier dynamics of polymeric organic semiconductor regioregular poly(3-hexylthiophen-2,5-diyl) (P3HT), an ideal p-type semiconductor and a widely used conjugated polymer, and blends with the fullerene derivative phenyl-C61-butyric acid methyl ester (PCBM), an electron acceptor material. The study was done with the help of time resolved microwave conductivity (TRMC) for contactless investigation of bulk carrier dynamics, optical spectroscopy, ultraviolet photoelectron spectroscopy(UPS) and high resolution X-ray absorption spectroscopy(XAS) which investigates excited states of rr-P3HT. From the data obtained we could infer the positions of the valence and conduction band, the existence of two excitons as well as the co-existence of one dimensional and two dimensional polarons. Based on our spectroscopic data we propose a model in which the scattering of virtual polarons and excitons are shown to create mobile polaronic charge carriers.