Light stability of ITO-free semi-transparent and opaque organic photovoltaic devices

Intrinsic light stability of transparent MoO₃/Ag/TiO₂ electrode is studied in four different polymer:fullerene solar cell configurations. We demonstrate that this stack can successfully replace ITO both in superstrate and substrate configurations required for non-transparent carriers. Although we observe that exposure of thin Ag layer directly to UV light reduces its conductivity, integration of a UV filter in the device package mitigates entirely this failure route. This enables us to show efficient and stable ITO-free cells both in superstrate and substrate configurations can reach identical stability as the ITO reference.