Aging of flat heterojunction zinc phthalocyanine/fullerene C₆₀ organic solar cells

Journal article

This work addresses the long-term aging of organic solar cells based on a flat zinc phthalocyanine (ZnPc)/C₆₀ heterojunction. We investigate both the typical degradation behavior of the short circuit current and of the saturated photocurrent, defined as I(−1V). The latter remains constant after a relatively small initial decay, which is directly related to a substantial reduction of the contribution of excitons generated in C₆₀ to the external quantum efficiency. Mass spectroscopy analysis of the organic material after aging revealed oxidized C₆₀ and sub-products thereof. The reduction of I(−1V) is thus attributed to the reaction of C₆₀ molecules with oxygen impurities. The results strongly suggest that ZnPc/C₆₀ photovoltaic cells are intrinsically very stable on a time scale of thousand of hours if such reactions are prevented. © 2009 Elsevier B.V.

Authors: Lessmann, R; Hong, Z; Scholz, S; Maennig, B; Riede, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Organic Electronics: physics, materials, applications
• Volume: 11
• Issue: 4
• Pages: 539-543
• Publication date: 2010-04-01
• DOI: 10.1016/j.orgel.2009.12.010
• ISSN: 1566-1199
• Language: English
• Keywords: C₆₀; ZnPc; Mass spectrometry; Solar cell; Oxidation; Aging; Stability; External quantum efficiency