Fully Slot-Die-Coated All-Organic Solar Cells

Solar cells are perhaps the most environmentally friendly way to generate electricity available. The main drawback is the relatively large investments required by conventional technologies. Organic photovoltaics could be much cheaper. Here, we produce and characterize fully slot-die-coated, all-organic devices in a roll-to-roll process using only cheap components, benign solvents, and materials with a low environmental impact. One of the main problems with this type of device is a predisposition for short circuits. The reason for this is here identified to be mechanical failures in the active layer due to swelling of the bottom electrode material during processing. A solution to the swelling problem is provided and fully functional devices are demonstrated. On an industrial scale, this process requires only very simple slot-die coating equipment and can offer very cheap solar cells that have a very low environmental impact over their life cycle.