High-performance screen-printed Au/Ba0.85Sr0.15TiO3/Pt capacitors for tunable devices

Abstract Metal-Ferroelectric-Metal capacitor structure, employing the lead free ferroelectric Ba0.85Sr0.15TiO3 thick films are successfully prepared by screen printing process on silicon platinized Pt/Ti/SiO2/Si substrates. The surface morphology and microstructure are analyzed by scanning electron microscope and X-ray diffraction. The thick film showed a well adhesion to the Pt/Ti/SiO2/Si substrate and uniform thickness of about ~20 µm. The frequency dependence of dielectric characteristics of BST thick films are systematically discussed and compared in a large temperature range. Ferroelectric characterizations, tunability and leakage current in the Au/BST(thick film)/Pt capacitor were also studied at room temperature by polarization cycles (P-V), Capacitance (C-V) and current (I-V) measurements. The high tunability (81%) combined with the low dielectric loss tangent and low leakage current makes Ba0.85Sr0.15TiO3 thick films one of the encouraging candidates for various modern electronic tunable devices.