Regensburg 2010 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 62: Poster II: Photovoltaics and Organic Semiconductors

HL 62.6: Poster

Donnerstag, 25. März 2010, 18:00–20:00, Poster D2

Transport and recombination in the low band gap polymer APFO-Green 9 — •David Vocke¹, Jens Lorrmann¹, Alexander Foertig¹, Carsten Deibel¹, L. Matthias Andersson², Olle Inganäs², and Vladimir Dyakonov^1,3 — ¹Experimental Physics VI, Physical Institute, Julius-Maximilians University of Würzburg, Am Hubland, D-97074 Würzburg — ²Biomolecular and Organic Electronics, IFM, Linköping University, S-5813 Linköping, Sweden — ³ZAE Bayern, Div. Functional Materials for Energy Technology, Am Hubland, D-97074 Würzburg

Increasing the short-circuit current is one way of improving power conversion efficiencies (PCE) of organic solar cells. This could be achieved by using a polymer with a low band gap like the novel copolymer APFO-Green 9. Organic solar cells based on APFO-Green 9 and [6,6]-phenyl-C71-butyric acid methyl ester (PCBM₇₀) show a high photo current of 6.5 mA/cm² and a PCE of 2.3%. We investigated how charge carrier transport and recombination contribute to the performance. Photo-CELIV (charge extraction by linearly increasing voltage), transient photo voltage- and transient photo current-methods are used to measure pure APFO-Green 9 and solar cells blended with PCBM₇₀ in different stoichiometries at various temperatures. Fitting the recombination dynamics with a continuity equation shows a strong charge carrier density dependent Langevin prefactor. Furthermore, we do not observe a relaxation-time dependent mobility, which is sometimes observed in poly(3-hexyl thiophene):[6,6]-phenyl-C₆₁ butyric acid methyl ester.