Nanocrystalline tio2 solar cells based on variable band gap poly(arylene ethynylene) conjugated polyelectrolytes

AEI 94

Hui Jiang, huijiang@chem.ufl.edu, Xiaoyong Zhao, xyzhao@chem.ufl.edu, and Kirk S. Schanze, kschanze@chem.ufl.edu. Department of Chemistry, University of Florida, PO Box 117200, Gainesville, FL 32611
A series of poly(arylene ethynylene) conjugated polyelectrolytes (CPEs) have been prepared, featuring a backbone consisting of a carboxylated bis(alkoxy)phenylene-1,4-ethynylene unit alternating with a second arylene ethynylene moiety (1,4-phenyl, 2,5-thienyl (Th), 2,5-(3,4-ethylenedioxy)thienyl (EDOT), and 1,4-benzo[2,1,3]-thiodiazole (BDT)). These different moieties were found to induce variation in the HOMO-LUMO band gap across the series. Using these CPEs as sensitizer, nanocrystalline TiO2 solar cells were fabricated and characterized. The IPCE and power conversion efficiency indicate close correlation with the band gap energy. The charge recombination process on the CPE sensitized TiO2 films were studied by nanosecond laser flash photolysis, and two lifetimes of tens and hundreds of ns were obtained.