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. (C) 2014 Elsevier Ltd. All rights reserved.