title: The origin of photovoltaic responses in BiFeO3 multiferroic ceramics.
abstract: Multiferroic BiFeO(3) (BFO) ceramics with electrodes of indium tin oxide (ITO) and Au thin films exhibit significant photovoltaic effects under near-ultraviolet illumination (λ = 405 nm) and show strong dependences on light wavelength, illumination intensity, and sample thickness. The correlation between photovoltaic responses and illumination intensity can be attributed to photo-excited and thermally generated charge carriers in the interface depletion region between BFO ceramic and ITO thin film. A theoretical model is developed to describe the open-circuit photovoltage and short-circuit photocurrent density as a function of illumination intensity. This model can be applied to the photovoltaic effects in p-n junction type BFO thin films and other systems. The BFO ceramic exhibits stronger photovoltaic responses than the ferroelectric Pb(1-x)La(x)(Zr(y)Ti(1-y))(1-x/4)O(3) (PLZT) ceramics under near-ultraviolet illumination. Comparisons are made with other systems and models for the photovoltaic effect.
authors.affiliation: Graduate Institute of Applied Science and Engineering, Fu Jen Catholic University, Taipei 24205, Taiwan. 039611@mail.fju.edu.tw
authors.forename: C-S
authors.initials: CS
authors.lastname: Tu
authors.forename: C-M
authors.initials: CM
authors.lastname: Hung
authors.forename: V H
authors.initials: VH
authors.lastname: Schmidt
authors.forename: R R
authors.initials: RR
authors.lastname: Chien
authors.forename: M-D
authors.initials: MD
authors.lastname: Jiang
authors.forename: J
authors.initials: J
authors.lastname: Anthoninappen