Screen-Printed Polymer:Fullerene Bulk-Heterojunction Solar Cells

Abstract

We demonstrate bulk heterojunction polymer solar cells fabricated by screen-printing, employing a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM). The devices with the structure of indium–tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) (PEDOT):poly(styrene sulfonate) (PSS)/P3HT:PCBM/Al was prepared in ambient condition with four different organic solvents. The screen-printed active layer using chloroform solvent exhibits improved surface morphology comparable to that of the spin-coated layer, resulting in the maximum efficiency of 4.23% under AM1.5 illumination at 1,000 W/m2. We also show the advantage of screen-printing for fabricating the polymer solar cells by connecting three sub-cells in series on the same substrate.