title: Near-IR light-sensitized voltaic conversion system using nanocrystalline TiO2 film by Zn chlorophyll derivative aggregate.
abstract: A Zn chlorophyll-a derivative, Zn chlorin-e6 (ZnChl-e6), adsorbed onto a nanocrystalline TiO2 film (ZnChl-e6/TiO2) electrode was prepared, and the photovoltaic properties of the ZnChl-e6/TiO2 electrode were studied. The absorption peaks of ZnChl-e6/TiO2 observed at 420, 654, and 795 nm were attributed to the ZnChl-e6 molecules aggregating onto TiO2 film. The fluorescence attributed to the ZnChl-e6 monomer and aggregate was observed at 710 and 820 nm, respectively, and the fluorescence in both cases was quenched by TiO2 particles. The maximum of the incident photon-to-current conversion efficiency (IPCE) value in the photocurrent action spectrum was 800 nm, and the IPCE value was 7.0%. ZnChl-e6 molecules formed aggregates on a nanocrystalline TiO2 film electrode. From the photocurrent-photovoltage characteristics of the ZnChl-e6/TiO2 electrode irradiated with 100 mW cm(-2), the short-circuit photocurrent (I(SC)) was found to be 0.19 mA cm(-2) and the open-circuit photovoltage (V(OC)) was found to be 375 mV. The maximum power was estimated to be 28.7 microW cm(-2), and the fill factor (FF) was estimated to be 40.1%. A near-IR light induced photovoltaic conversion system using a ZnChl-e6 aggregate formed onto a nanocrystalline TiO2 film electrode was achieved.
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 / Q000737:chemistry*; D003460:Crystallization; D004566:Electrodes; D008027:Light; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D010777:Photochemistry; D013057:Spectrum Analysis; D014025:Titanium / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D002734:Chlorophyll; C009495:titanium dioxide; D014025:Titanium; D015032:Zinc