4% Efficient Polymer Solar Cells on Paper Substrates

Lightweight, biodegradable, and inexpensive materials are desirable to enable low-cost photovoltaics. Paper fulfills these requirements and is compatible with standard roll-to-roll printing processes. Here we report 4% efficient organic solar cells fabricated on paper substrates with a zinc-coating acting as the back contact and evaporated MoO3/Ag/MoO3 semitransparent top electrodes. We demonstrate that the rough surface of paper does not preclude its use in high-efficiency organic photovoltaics.