Temperature dependent leakage current behavior of pulsed laser ablated SrBi2Ta2O9 thin films

Abstract

Polycrystalline SrBi2Ta2O9 (SBT) thin films were grown on Pt/Ti/SiO2/Si substrates by pulsed laser ablation technique. Phase analyses of the deposited films were studied by grazing incidence x-ray diffraction. Microstructural and interfaces of the SBT film were investigated using a field emission scanning electron microscope. The dc leakage current behavior was studied at different temperatures, and the current transport mechanism was investigated. The calculated activation energies from the Arrhenius plot were attributed to the shallow traps existing near the conduction band of the SBT thin films. The current-voltage plot could be clearly separated into three regions, i.e., Ohm’s law, trap-filled limited, and Child’s law. At a low electric field, the current density–voltage characteristics showed the Ohmic behavior. Lampert’s theory of space charge limited conduction was found to be suitable to explain the current conduction through SBT films. The trap-filled limited voltage increases with increasing temperature up to 100 °C and then decreases with temperature.