Influence of material migration on the mechanical integrity of inverted organic solar cells

Aurélien Tournebize (1, 2) , Dargie Deribew (3) , Alberto Gregori (4) , Roger C. Hiorns (4) , Andreas Distler (3) , Hans-Joachim Egelhaaf (3) , Christine Lartigau-Dagron (4) , Ahmed Allal (4) , Agnès Rivaton (2) , Heiko Peisert (1) , Thomas Chassé (1)

1 Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen
2 ICCF - Institut de Chimie de Clermont-Ferrand
3 Belectric OPV GmbH, Nürnberg
4 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

We have identified modifications of material distributions in inverted organic solar cell structures during accelerated aging processes that are potentially linked to the loss of the mechanical integrity of the devices. Non-encapsulated devices were treated with ISOS-D-3 ageing (the so called damp heat exposure at 85 °C/85% room humidity in the dark). After performing pull-off tests, the exposed surfaces were analyzed by X-ray photoemission spectroscopy and atomic force microscopy. For fresh devices, the results revealed that mechanical failure occurs close to the PEDOT:PSS/P3HT:PCBM interface, in agreement with the literature. However, after a short exposure to damp heat, XPS investigations indicate an enrichment of PCBM at the PEDOT:PSS/P3HT:PCBM interface and a change in the 2 PEDOT:PSS surface composition. Both phenomena may explain the rapid drop in device performances and the increased tendency towards delamination.

Keywords: delamination; PCBM diffusion; ISOS-D3; Stability

Domains: Chemical Sciences

Aurélien Tournebize, Dargie Deribew, Alberto Gregori, Roger C. Hiorns, Andreas Distler, et al.. Influence of material migration on the mechanical integrity of inverted organic solar cells. Solar Energy Materials and Solar Cells, 2019, 200, pp.110008. ⟨10.1016/j.solmat.2019.110008⟩. ⟨hal-03085962⟩