Carbon: The Ultimate Electrode Choice for Widely Distributed Polymer Solar Cells

As mass-produced, low-cost organic electronics enter our everyday lives, so does the waste from them. The challenges associated with end-of-life management must be addressed by careful design and carbon-based electrodes are central to these developments. Here, the reproducible production of vacuum-, indium tin oxide (ITO)-, and silver-free solar cells in a fully packaged form using only roll-to-roll processing is reported. Replacing silver with carbon as electrode material significantly lowers the manufacturing cost and makes the organic photovoltaic (OPV) modules environmentally safe while retaining their flexibility, active area efficiency, and stability. The substitution of silver with carbon does not affect the roll-to-roll manufacturing of the modules and allows for the same fast printing and coating. The use of carbon as electrode material is one step closer to the wide release of low-cost plastic solar cells and opens the door to new possible applications where silver recycling is not manageable.