We report a remarkable photovoltaic effect in pulsed laser deposited multiferroic aurivillius phase Bi₅FeTi₃O₁₅ (BFTO) thin films sandwiched between ZnO:Al transparent conductive oxide top electrode and SrRuO₃ bottom electrode fabricated on amorphous fused silica substrates. The structural and micro structural properties of these films were analysed by X-ray diffraction and atomic force microscopy techniques. The films were showing a photo sensitive ferroelectric behaviour with a notable apparent polarization in the range of 10–15 μC/cm². These films also exhibited a switchable photo-response and this parameter was observed to be sensitive to polarisation field and the polarization direction. The device shows a large ON/OFF photo current ratio with an open circuit voltage of 0.14 V. The photo response at zero bias of this BFTO based heterostructures showed rapid increase to a saturation value of 6 μA at zero bias.

Forming-free resistive random access memory (ReRAM) devices having low switching voltages are a prerequisite for their commercial applications. In this study, the forming-free resistive switching characteristics of graphene oxide (GO) films embedded with gold nanoparticles (Au Nps), having an enhanced on/off ratio at very low switching voltages, were investigated for non-volatile memories. The GOAu films were deposited by the electrophoresis method and as-grown films were found to be in the low resistance state; therefore no forming voltage was required to activate the devices for switching. The devices having an enlarged on/off ratio window of ∼10 ⁶ between two resistance states at low voltages (<1 V) for repetitive dc voltage sweeps showed excellent properties of endurance and retention. In these films Au Nps were uniformly dispersed over a large area that provided charge traps, which resulted in improved switching characteristics. Capacitance was also found to increase by a factor of ∼10, when comparing high and low resistance states in GOAu and pristine GO devices. Charge trapping and de-trapping by Au Nps was the mechanism responsible for the improved switching characteristics in the films.

Doubly substituted [Bi_0.9La_0.1][Fe_0.97Ta_0.03]O₃ (BLFTO) films were fabricated on Pt/TiO₂/SiO₂/Si substrates by pulsed laser deposition. The ferroelectric photovoltaic properties of ZnO:Al/BLFTO/Pt thin film capacitor structures were evaluated under white light illumination. The open circuit voltage and short circuit current density were observed to be ∼0.20 V and ∼1.35 mA/cm², respectively. The band gap of the films was determined to be ∼2.66 eV, slightly less than that of pure BiFeO₃ (2.67 eV). The PV properties of BLFTO thin films were also studied for various pairs of planar electrodes in different directions in polycrystalline thin films.