Patternable conjugated polymers for organic solar cells

Abstract

Photocrosslinking is known as a suitable method for patterning organic semiconductors in organic light emitting diodes. We extend this concept to the field of organic solar cells using conjugated polymers bearing sidechains with photocrosslinkable oxetane units. By UV irradiation in the presence of a photo acid generator the oxetane groups polymerize, leading to the formation of a densely crosslinked, and thus insoluble, network of a low-bandgap polymer. In this paper we present the synthesis of two novel photocrosslinkable low-bandgap polymers PFDTBTOx and PCDTBTOx and discuss several strategies for the fabrication of organic solar cells taking advantage of the novel crosslinkable materials.