A Low-Band-Gap Polyfluorene Derivative for Use in Polymer Solar Cells

Abstract

The novel soluble conjugated copolymer (PFTBzTT) derived from 4,7-dithienyl-2,1,3-benzothiadiazole, 9,9’-dioctylfluorene and 2,2’-bisthiophene was polymerized by a palladium catalyzed Suzuki type cross-coupling reaction. The copolymer obtained showed light absorption from 300 to 600 nm and photoluminescence from about 600 to 850 nm. The polymer-based solar cells could be prepared via solution deposition techniques (spin coating). The cells showed power conversion efficiency of 0.78 % when using PFTBzTT as donor and PCBM as acceptor with a ratio of 1 to 3 (w/w)