title: Photovoltaic conversion using Zn chlorophyll derivative assembled in hydrophobic domain onto nanocrystalline TiO2 electrode.
abstract: Photovoltaic conversion using zinc chlorin-e6 (ZnChl-e6), which is zinc chlorophyll-a derivative, and fatty acid (myristic acid or cholic acid) co-adsorbed nanocrystalline TiO2 layer onto ITO glass (OTE) electrode is developed. The maximum peaks of photocurrent action spectrum of the ZnChl-e6 adsorbed TiO2 layer onto OTE (ZnChl-e6/TiO2) are 400, 660 and 800 nm, respectively. Especially the IPCE value at 800 nm (7.5%) is larger than that of 660 nm (6.9%). This result indicates that ZnChl-e6 molecules is aggregated or formed dimer on a nanocrystalline TiO2 layer onto OTE and the absorption band is shifted to near IR region. The photocurrent action spectrum of ZnChl-e6 and cholic acid adsorbed TiO2 layer onto OTE (ZnChl-e6-Cho/TiO2 is similar to that of the UV-vis absorption spectrum in methanol solution, and IPCE values at 400 and 660 nm (8.1%) increase and the IPCE value at 800 nm (4.1%) decreases, indicating that the aggregation of ZnChl-e6 molecules on the TiO2 is suppressed by cholic acid. By using ZnChl-e6-Cho/TiO2, the short-circuit photocurrent density and open-circuit photovoltage also increase compared with that of ZnChl-e6 adsorbed nanocrystalline TiO2 electrode.
authors.affiliation: Department of Applied Chemistry, Oita University, Dannoharu 700, Oita 870-1192, Japan. amao@cc.oita-u.ac.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Amao
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D002734:Chlorophyll / Q000031:analogs & derivatives*; D004563:Electrochemistry; D004566:Electrodes; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D053758:Nanoparticles; D014025:Titanium; D015032:Zinc
chemical_list: D002734:Chlorophyll; C009495:titanium dioxide; D014025:Titanium; D015032:Zinc