Parts | Days | Selection | Search | Updates | Downloads | Help
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 12: Organic Semiconductors II: Solar Cells B (jointly with HL, DS)
CPP 12.3: Talk
Tuesday, March 15, 2011, 11:15–11:30, ZEU 222
Sub-Bandgap Absorption in Polymer-Fullerene Solar Cells — •Martin Presselt1, Felix Herrmann1, Marco Seeland1, Maik Bärenklau1, Roland Rösch1, Wichard J. D. Beenken2, Erich Runge2, Sviatoslav Shokhovets1, Harald Hopp1, and Gerhard Gobsch1 — 1Experimental Physics I, Institute of Physics & Institute of Micro- und Nanotechnologies, Ilmenau University of Technology, Weimarer Str. 32, 98693 Ilmenau, Germany — 2Theoretical Physics I, Institute of Physics, Ilmenau University of Technology, Weimarer Str. 25, 98693 Ilmenau, Germany
We present external quantum efficiency (EQE) studies of P3HT:PCBM based bulk heterojunction polymer solar cells with improved intensity resolution in the sub-bandgap (SBG) region, i.e. the energy range below the optical bandgaps of the pristine materials. Varying the P3HT:PCBM blending ratio, we find that in addition to a Gaussian profile an exponential tail is needed for a quantitative description of the SBG EQE spectra. To gain insights into the origin of the single contributions, absorption and emission spectra covering several decades of intensity and SBG EQE signals are discussed in detail.