Mass-printed polymer/fullerene solar cells on paper

A simple approach to print polymer/fullerene solar cells on paper substrates has been developed by Prof. Arved Hübler and his group, Institute for Print and Media Technology, Chemnitz University of Technology, Germany. The solar cell is free from expensive indium-tin-oxide and does not employ any vacuum process. Polymer/fullerene solar cells are printed on paper substrate by the combination of gravure and flexographic printing techniques in ambient conditions. The process does not require any vacuum steps. A Paper-roll of printed solar cells is shown. Solar modules can be made by any unskilled person just by cutting the rolls into desired sizes and connecting them with the help of commercial snap fasteners. The vision is to produce cheap, disposable and use-and-throw solar cells anywhere in the world, which can be printed by nearby printers or copy-shops and do not require any technical skill.

Only three roll-to-roll printing steps were used, under normal room conditions, to print the complete solar cells. Naturally oxidized zinc film, printed by transfer printing on paper, acts as cathode. Photoactive layer is a bulk hetrojunction of polymer/fullerene, printed by gravure printing. Poly (3, 4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT: PSS), printed by flexographic printing, acts as transparent anode. Gravure and flexographic printing processes are well-established techniques in conventional printing with a resolution of down to 10 µm, high printing speeds (up to 15 m/s) and low wastage of ink.