Combined effect of strontium content and electrode type on electrical properties of BaxSr1-xTiO3 thin-films

Official URL: http://risc01.sabanciuniv.edu/record=b1649235 (Table of Contents)

Ferroelectric thin films have been on agenda of many research groups and the semiconductor industry for applications ranging from non‐volatile data storage to tunable capacitors and antennas. In much of these works, the fact that ferroelectrics can be sensitive to the electrical boundary conditions, namely the type of the electrodes employed, is often taken for granted without an in‐depth analysis. In this thesis work, we focus on BaxSr1‐xTiO3 compositions, a well‐known system, grown via a sol‐gel method on conducting Nb:SrTiO3 bottom electrodes to explore the effect of the Sr content and the top/bottom electrode asymmetry on the electrical characteristics of these systems. Following structural and morhphological characterization for quality check of the films, we extensively focus on a process called “resistive switching”, which we repeatedly observed in our samples. Resistive switching phenomena is a topic of interest as the direction of the ferroelectric polarization determines whether there will be carrier depletion or accumulation in the semiconducting electrode (the conducting oxide bottom electrode in this thesis), upon which various novel device and transistor designs have been recently proposed by a number of groups. In this work, we focus on the experimental evidence for resistive switching in the light of thermodynamic theory of these systems and discuss the effect of Sr content on current‐voltage characteristics of our samples.