Near-IR dye sensitization of polymer blend solar cells

Abstract We have fabricated ternary blend solar cells based on poly(3-hexylthiophene) (P3HT) as a donor material, poly{[ N , N ′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]- alt -5,5′-(2,2′-bithiophene)} (N2200) as an acceptor material, and a silicon naphthalocyanine derivative (SiNc) as a near-IR sensitizer. In order to discuss how molecular structures impact the dye sensitization in P3HT/N2200 solar cells, we studied two SiNc molecules with different axial groups: SiNc10 with decyldimethylsilyl oxide and SiNc6 with trihexylsilyl oxide. As a result, P3HT/N2200/SiNc10 ternary solar cells exhibited a power conversion efficiency of 1.4%, which is improved by 73% compared to P3HT/N2200 binary solar cells and also by 17% compared to P3HT/N2200/SiNc6 ternary solar cells. We discuss the origin of the improvement in the device performance in terms of dye location in ternary blend films.