Investigation on optical illumination effect on transport properties and resistive switching of poly crystalline BiFeO3/ITO heterojunction

In the present studies we reported the optical modulation of charge transport and resistive switching behavior in polycrystalline BiFeO₃ thin film deposited ITO coated glass substrate via the chemical solution deposition technique. Structural analysis using grazing angle incidence X-ray diffraction (GIXRD) confirms the formation of polycrystalline BiFeO3 phase. The current-voltage characteristics were measured under both dark and illuminated conditions (White light LED 450–470 nm Philips LUXEON 3030 2D) in a current perpendicular to plane (CPP) configuration with Ag as top electrode and ITO as bottom electrode at room temperature .Optical illumination significantly enhanced the current response,notably at +1 V suggesting efficient photoinduced carrier generation and transport .Resistive switching, investigated under cyclic bias of 0 V → +2 V → 0 V → -2 V → 0 V,exhibited notable improvement in switching performance under illumination. Charge transport analysis indicates that the conduction is governed by space charge limited current (SCLC) mechanism under both dark and light conditions. These findings demonstrate a strong correlation between optical excitation and resistive switching in BiFeO3 films, providing insights into the design of photo assisted nonvolatile memory elements and light responsive oxide electronics.