Forming-Free Unipolar Resistive Switching in BiFe0.95Co0.05O3 Films

We report the forming-free unipolar resistive switching effects in polycrystalline BiFe0.95Co0.05O3 films which were spin-coated on ITO/glass substrates by a chemical solution deposition method. The resistive ratio of the high resistive state (HRS) to the low resistive state (LRS) is more than 2 orders of magnitude. The conduction of the HRS is dominated by the space-charge-limited conduction mechanism, while Ohmic behavior dominates the LRS, which suggests a filamentary conduction mechanism. The oxygen vacancies are considered to play an important role in forming the conducting filaments.