Photocurrent increment in organic solar cell with mixed solid of merocyanine and zinc porphyrin

• Published in: Thin solid films 1998-11, Vol.333 (1), p.256-263
• Main Authors: Takahashi, Kohshin, Higashi, Masanori, Tsuda, Yoshihiro, Yamaguchi, Takahiro, Komura, Teruhisa, Ito, Shoji, Murata, Kazuhiko
• Format: Article
• Language: English
• Subjects: Applied sciences; Energy; Exact sciences and technology; Merocyanine; Natural energy; Organic mixed film; Organic solar cell; Photovoltaic conversion; Photovoltaic effect; Solar cells. Photoelectrochemical cells; Solar energy; Zinc porphyrin
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(98)00821-9

The short-circuit photocurrent in Al/dye/Au sandwich-type cell with a mixed solid of 3-ethyl-5-[(3-ethyl-2(3H)-benzothiazolylidene)ethylidene]-2-thioxo-4-thiazolidinone (MC) and 5,10,15,20-tetraphenylporphyrinatozinc (Zntpp) was much larger than that in the cell with a pure MC solid or a pure Zntpp solid. The maximum photocurrent quantum yields of 7.4% at 440 nm monochromatic light absorbed mainly by Zntpp and 4.7% at 555 nm monochromatic light absorbed by both MC and Zntpp were obtained for the mixed solid cells of R=0.35 and R=0.23, respectively, where R indicates the molar ratio of Zntpp to total dye. Since the hole density in the organic solid decreased with mixing Zntpp into MC solid, this improvement was not explained by this factor. We believe that a dissociation efficiency of a photoproduced electron-hole pair (exciton) in the mixed solid may have increased because of relatively large intermolecular interaction between MC and Zntpp molecules. This effect is considered to be responsible for this photocurrent increment.