Improved leakage property and reduced crystallization temperature by V2O5 seed layer in K0.4Na0.6NbO3 thin films derived from chemical solution deposition

K0.4Na0.6NbO3 (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 (2Prmax = 26 μC/cm2, ε = 796, tan δ = 0.04) and low leakage current density (4.0 × 10−5 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).

► V2O5 as the seed layer.
► The seed layer for modifying the quality and the properties of the KNN-based films.
► The crystallization temperature was reduced to 425 °C by seed layer adding.
► The leakage current density was greatly reduced by seed layer adding.