Effect of excess Bi content on electrical properties of BiFe0.95Cr0.05O3 thin films

The Bi1 + xFe0.95Cr0.05O3 (BFCO) (x = 0, 5, 10, 15 and 20%) thin films are fabricated on FTO/glass substrate using a chemical solution deposition method and sequential-layer annealing process. The effects of the excess Bi content on crystalline structure, morphology, and electrical performance of BFCO thin films are investigated. All the BFCO thin films are crystallized into polycrystalline perovskite structure and belonging to the space group of R3c. The BFCO thin films with 5 and 10% excess Bi contents possess no impurity phase. Especially, a dense surface morphology and columnar crystal structure can be obtained for the film with 5% excess Bi content. Especially, the one possesses superior ferroelectricity with a relative high remnant polarization (Pr) of 69.8 µC/cm2 and low coercive electric field (Ec) of 291 kV/cm at 1 kHz due to the relatively low leakage current density of 3.04 × 10− 5 A/cm2 at 200 kV/cm.