Enhanced photoresponse in BiFeO3/SrRuO3 heterostructure

We report photovoltaic effect and photo response in multiferroic BiFeO3 (BFO) thin films. Pure phase of polycrystalline BFO thin films have been deposited on SRO/Pt/TiO2/SiO2/Si substrates by RF sputtering. The as grown BFO thin films showed good ferroelectric properties and antiferromagnetic characteristics at room temperature. The diode like characteristics at the interface of BFO/SRO thin films were observed through current-voltage measurements. The open circuit voltage (Voc) and short circuit current density (Jsc) were measured as ∼0.08 V and ∼ −63 μA/cm2 respectively with illumination of white light density ∼1 kW/m2. The photo response at zero bias voltage of BFO capacitor showed a rapid increase of the photocurrent which saturated at a value ∼ −63 μA/cm2 followed by a rapid decrease with negligible delay to reach its original state during periodic on and off state of the light source. This high sensitivity makes it possible for the BFO films to be applied in a photosensitive capacitor.