Dependence on Material Choice of Degradation of Organic Solar Cells Following Exposure to Humid Air

Electron microscopy has been used to study the degradation of organic solar cells when exposed to humid air. Devices with various different combinations of commonly used organic solar cell hole transport layers and cathode materials have been investigated. In this way the ingress of water and the effect it has on devices can be studied. It was found that calcium and aluminium in the cathode both react with water, causing voids and delamination within the device. The use of PEDOT:PSS was found to increase the degradation by easing water ingress into the device. Replacing these materials removed these degradation features.This work was funded by the EPSRC (grant: EP/I029257/1).This is the final published version of the article. It was originally published in the Journal of Polymer Science Part B: Polymer Physics (Glen, T. S., Scarratt, N. W., Yi, H., Iraqi, A., Wang, T., Kingsley, J., Buckley, A. R., Lidzey, D. G. and Donald, A. M., J. Polym. Sci. B Polym. Phys., 2015, doi: 10.1002/polb.23905). The final version is available at http://dx.doi.org/10.1002/polb.2390