Investigating local (photo-)current and structure of ZnPc:C₆₀ bulk-heterojunctions

Journal article

The performance of organic solar cells strongly depends on the nanoscale structure of the used mixed absorber layer. Utilizing photoconductive and conductive atomic force microscopy (pcAFM and cAFM), as well as transmission X-ray microscopy (TXM), we investigate the influence of different substrate temperatures T_sub on the thin-film structure and local photocurrent in bulk-heterojunctions (BHJs) of vacuum deposited zinc phthalocyanine (ZnPc) and Buckminsterfullerene (C₆₀) mixed absorber layers. In this paper, we present topography maps, photocurrent maps under short-circuit current conditions, dark-current maps, and TXM images with high lateral resolution down to 25nm. We observe a strong influence of the substrate temperatures during deposition T_sub on the nanoscopical segregation of the two components in the BHJ. This segregation leads to a spatial extension of the dark-current and a reduced short-circuit current at higher substrate deposition temperatures T_sub. © 2013 Elsevier B.V.

Authors: Mönch, T; Murawski, J; Elschner, C; Riede, M; Müller-Meskamp, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Organic Electronics: physics, materials, applications
• Volume: 14
• Issue: 11
• Pages: 2777-2788
• Publication date: 2013-11-01
• DOI: 10.1016/j.orgel.2013.07.031
• ISSN: 1566-1199
• Language: English
• Keywords: X-ray; Bulk-heterojunction; Photocurrent; pcAFM; Atomic force microscopy; OPV