title: Study of hybrid solar cells made of multilayer nanocrystalline titania and poly(3-octylthiophene) or poly-(3-(2-methylhex-2-yl)-oxy-carbonyldithiophene).
abstract: Hybrid solar cells have been constructed by using nanocrystalline titania and hole-transporting polymers. Titania was deposited on fluorine-doped tin-oxide transparent electrodes in three layers: a blocking layer and two nanostructured layers, giving densely packed or open structures. Open structures produced higher currents due to better polymer penetration and larger oxide-polymer interface. Cells based on the dithiophene-unit-containing polymer gave higher open-circuit voltage. Efficient cells could be made only in the presence of a dye sensitizer and a lithium salt. Cells were neither sealed nor encapsulated and their components were deposited under ambient conditions except for the metal back electrode, which was deposited under vacuum. Cells demonstrated a transient behavior in two stages: initially an increase of both current and voltage followed by an increase in voltage and a drop in current. Both quantities were stabilized at values approximately established within a few days. These values remained stable for several months when the cells were stored in the dark.
authors.affiliation: Engineering Science Department, University of Patras, GR-26500 Patras, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Antoniadou
authors.forename: Elias
authors.initials: E
authors.lastname: Stathatos
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Boukos
authors.forename: Andreas
authors.initials: A
authors.lastname: Stefopoulos
authors.forename: Joannis
authors.initials: J
authors.lastname: Kallitsis
authors.forename: Frederik C
authors.initials: FC
authors.lastname: Krebs
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Lianos