Fabrication and Characterization of PCBM: P3HT-based Thin-film Organic Solar Cells with Zinc Phthalocyanine and 1,8-Diiodooctane

Abstract

[6,6]–phenyl C 61 –butyric acid methyl ester (PCBM) and poly(3–hexylthiophene) (P3HT) bulk heterojunction solar cells added with zinc–tetra–tertiary–butyl–phthalocyanine (ZnPc) and 1,8–diiodooctane (DIO) were fabricated and characterized. Incident photon-to-current conversion efficiencies in the range of 400–650 nm were increased by the ZnPc addition, and the absorption range of ZnPc overlapped with the photoluminescence range of P3HT. Photovoltaic properties of the solar cells with an inverted structure were improved by the ZnPc and DIO addition. Microstructures of the thin films were analyzed by X-ray diffraction. The improvement would be due to the Förster energy transfer mechanism the direct charge transfer from ZnPc to PCBM, and the phase separation of PCBM and P3HT by the DIO addition would also contribute the improvement.