Copper substrate electrode for efficient top-illuminated organic photovoltaics

It is now recognized that for solution processed organic photovoltaics (OPVs) to be manufactured on a large scale the thickness of the photoactive layer must be substantially increased beyond the currently used ≤150 nm. We show that copper can replace silver as the reflective substrate electrode in high performance top-illuminated OPVs without compromising device power conversion efficiency when the photoactive layer is thick enough to absorb the majority of incident photons on first pass through the photo-active layer. Copper is one hundredth of the cost of Ag, enabling a significant reduction in the bill of materials for OPV manufacture