title: A metallocene molecular complex as visible-light absorber for high-voltage organic-inorganic hybrid photovoltaic cells.
abstract: A thin solid-state dye-sensitized photovoltaic cell is fabricated by composing organic and inorganic heterojunctions in which the visible-light sensitizers are cyclopentadiene derivatives (Cp*) coordinated to a metal oxide, typically TiO2. The coordination bonds of the metallocene molecular complex (Ti-Cp*) create a new LMCT (ligand-to-metal charge transfer) absorption band and induce a rectified charge transfer from the organic ligands to TiO2, leading to photocurrent generation. Photovoltaic junctions are completed by coating crystalline organic molecules (perylene) as a hole-transport layer on the Cp*-coordinated TiO2 surface by using the vapor deposition method. The molecular plane of Cp* on the TiO2 surfaces seems to help the hole-transport layer to form ordered structures, which effectively improve carrier conductivities and minimize interfacial resistance. The organic-inorganic hybrid thin-film photocell with metallocene molecular complexes is capable of generating high open-circuit voltages exceeding 1.2 V.
authors.affiliation: Dr. Ayumi Ishii, Prof. Tsutomu Miyasaka, Graduate School of Engineering, Toin University of Yokohama, 1614 Kurogane-cho, Aoba, Yokohama, Kanagawa 225-8503 (Japan).
authors.forename: Ayumi
authors.initials: A
authors.lastname: Ishii
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Miyasaka
keywords: absorber; dye-sensitized solar cells; electrochemistry; hybrid photovoltaics; metallocene