Photovoltaic phenomena in BiFeO3 multiferroic ceramics

Abstract

Open-circuit photovoltage and short-circuit photocurrent were investigated in BiFeO3 (BFO) ceramics as functions of laser wavelength (λ = 373 and 532 nm), illumination intensity, and sample thickness. BFO ceramics exhibit significant photovoltaic responses under near-ultraviolet illumination of λ = 373 nm. The photovoltaic responses strongly depend on wavelength, light intensity, and sample thickness. The relation between photovoltaic responses and light intensity can be described by exponential equations, E OC = E S[1 – exp(–I/α)] and J SC = J S[1 – exp(−I/β)]. E OC, J SC, E S, and J S are open-circuit photovoltage (V/cm), short-circuit photocurrent density (A/cm2), saturated photovoltage (V/cm), and saturated photocurrent density, respectively. This work suggests that BFO ceramic exhibits stronger photovoltaic responses than the ferroelectric WO3-doped Pb1-x La x (Zr y Ti z )1-x/4O3ceramics and Pb(Mg1/3Nb2/3)1-x Ti x O3 crystals.