Effect of heterojunction order between CaTiO₃ and Mn doped SrTiO₃ on memristive performance and its mechanism analysis

It is well-known that memristive devices can be applied to brain-like parallel computing, but the interface effects have an indelible impact on memristive performance. In this work, two memristive devices with Ag/CTO/SMTO/Ti and Ag/SMTO/CTO/Ti structures were fabricated based on the heterojunctions between CaTiO₃ (CTO) and Mn-doped SrTiO₃ (SMTO). By comparison, the Ag/CTO/SMTO/Ti device shows relatively improved memristive characteristics with the optimum sweeping voltage of 1.2 V and the switching ratio of ∼12. That is to say, changing the heterojunction order between CTO and SMTO can regulate the memristive behaviors of the device because the interface effect caused by heterojunction contact has influence on the particle migration, resulting in different rates of conductive filaments formation, so that the memristive characteristics of the device can be regulated. Finally, the resistive switching (RS) characteristics of the device are explained by in-depth mechanism analysis based on fitting experimental data. Therefore, this work not only provides a feasible method for improving the memristive characteristics of the device, but also helps to understand the influence of the interface effect on the particles motion, thereby laying the foundation for the preparation of high-capacity and efficient memristive device in artificial intelligence (AI) applications.