Improved leakage property and reduced crystallization temperature by V ₂O₅ seed layer in K_0.4Na_0.6NbO ₃ thin films derived from chemical solution deposition

K_0.4Na_0.6NbO₃ (KNN) thin films were prepared by chemical solution deposition. The V₂O₅ seed layer was introduced to modify the quality and electric properties of the thin films. The results show that the V₂O₅ seed layer can reduce the crystallization temperature to 425 °C and largely improve the leakage property of the KNN thin films. The KNN thin film with 5 nm thickness V₂O₅ seed layer exhibits high ferroelectric and dielectric properties (2Pr_max = 26 μC/cm², ε = 796, tanδ = 0.04) and low leakage current density (4.0 × 10⁵ A/cm²) at the electric field of 350 kV/cm at room temperature. By adding the V₂O₅ seed layer, the conduction mechanism changes from SCLC mechanism to Ohmic mechanism in the lower electric field (<200 kV/cm), and the Schottky emission mechanism is replaced by the Poole-Frenkel emission mechanism in the higher electric field (>200 kV/cm).