Photodegradation of Si-PCPDTBT:PCBM active layer for organic solar cells applications: a surface and bulk investigation.

Aurélien Tournebize (1, 2) , Mamadou Seck (3, 4) , Andrej Vincze (3, 4) , Andreas Distler (5) , Hans-Joachim Egelhaaf (6) , Christoph J. Brabec (6) , 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 International Laser Centre, Bratislava
4 Institute of Electronics and Photonics, Slovak University of Technology
5 Belectric OPV GmbH, Nürnberg
6 ZAE Bayern

The photooxidation of a polymer blend film used in efficient solar cells based on poly[(4,40-bis(2-ethylhexyl)dithieno[3,2-b:20,30- d]silole)-2,6-diylalt-(2,1,3-benzothiadiazole)-4,7-diyl], (Si-PCPDTBT) and [6,6]-phenyl-C71-butyric acid methyl (PC70BM) has been investigated. A set of experiments from complementary techniques was developed to monitor the modifications during ageing that occur not only in the bulk but also at the surface. The surface analyses were performed by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), and the bulk analyses by UV–visible spectroscopy and infrared (IR) spectroscopy. The results reveal that the silicon bridge atom is the first target of degradation. We have identified the existence of a photooxidation profile within the 300 nm thick film. Such a heterogeneous degradation was confirmed by time-of-flight secondary ion mass spectrometry (TOF-SIMS) depth profiling.

Mots clés: Organic solar cell; Active layer; Degradation; Photooxidation profile

Domaines: Chimie

Aurélien Tournebize, Mamadou Seck, Andrej Vincze, Andreas Distler, Hans-Joachim Egelhaaf, et al.. Photodegradation of Si-PCPDTBT:PCBM active layer for organic solar cells applications: a surface and bulk investigation. . Solar Energy Materials and Solar Cells, 2016, 155, pp.323-330. ⟨10.1016/j.solmat.2016.06.026⟩. ⟨hal-01477668⟩