The Effect of Diiodooctane on the Charge Carrier Generation in Organic Solar Cells Based on the Copolymer PBDTTT-C

Please always quote using this URN: urn:nbn:de:bvb:20-opus-125022
  • Microstructural changes and the understanding of their effect on photocurrent generation are key aspects for improving the efficiency of organic photovoltaic devices. We analyze the impact of a systematically increased amount of the solvent additive diiodooctane (DIO) on the morphology of PBDTTT-C:PC71BM blends and related changes in free carrier formation and recombination by combining surface imaging, photophysical and charge extraction techniques. We identify agglomerates visible in AFM images of the 0% DIO blend as PC71BM domains embeddedMicrostructural changes and the understanding of their effect on photocurrent generation are key aspects for improving the efficiency of organic photovoltaic devices. We analyze the impact of a systematically increased amount of the solvent additive diiodooctane (DIO) on the morphology of PBDTTT-C:PC71BM blends and related changes in free carrier formation and recombination by combining surface imaging, photophysical and charge extraction techniques. We identify agglomerates visible in AFM images of the 0% DIO blend as PC71BM domains embedded in an intermixed matrix phase. With the addition of DIO, a decrease in the size of fullerene domains along with a demixing of the matrix phase appears for 0.6% and 1% DIO. Surprisingly, transient absorption spectroscopy reveals an efficient photogeneration already for the smallest amount of DIO, although the largest efficiency is found for 3% DIO. It is ascribed to a fine-tuning of the blend morphology in terms of the formation of interpenetrating donor and acceptor phases minimizing geminate and nongeminate recombination as indicated by charge extraction experiments. An increase in the DIO content to 10% adversely affects the photovoltaic performance, most probably due to an inefficient free carrier formation and trapping in a less interconnected donor-acceptor network.show moreshow less

Download full text files

Export metadata

Additional Services

Share in Twitter Search Google Scholar Statistics
Metadaten
Author: Andreas Zusan, Björn Gieseking, Mario Zerson, Vladimir Dyakonov, Robert Magerle, Carsten Deibel
URN:urn:nbn:de:bvb:20-opus-125022
Document Type:Journal article
Faculties:Fakultät für Physik und Astronomie / Physikalisches Institut
Language:English
Parent Title (English):Scientific Reports
Year of Completion:2015
Volume:5
Pagenumber:8286
Source:SCIENTIFIC REPORTS 5 : 8286. DOI: 10.1038/srep08286 (2015)
DOI:https://doi.org/10.1038/srep08286
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 62 Ingenieurwissenschaften / 621 Angewandte Physik
Tag:electronic properties and materials; photonic devices
Release Date:2016/02/02
Collections:Open-Access-Publikationsfonds / Förderzeitraum 2015
Licence (German):License LogoCC BY: Creative-Commons-Lizenz: Namensnennung