Structure in ternary blend systems for organic photovoltaics

The incorporation of an organic dye in the active layer of a polymer-based solar cell and its structural and spectroscopic influence is investigated. The phthalocyanine derivative, 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (OPc), is incorporated in the blend of poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 (PCBM) forming a ternary blend which expands the absorption range as compared with the binary P3HT:PCBM system. Absorption and structural characterizations of the single components and the ternary blend films reveal structural changes due to blending and annealing of the ternary system. The OPc is found to be homogenously distributed in the polymer-based film rather then aggregating. Photovoltaic performance measurements complement the investigation showing the absence of improvement by addition of OPc.