Unipolar resistive switching in planar Pt/BiFeO3/Pt structure

Rajesh K Katiyar,Ram S Katiyar,Brad R Weiner,Shojan P Pavunny,Pankaj Misra,Sudheendran Kooriyattil,Yogesh Sharma,Danilo G Barrionuevo Diestra,Gerardo Morell,J F Scott

doi:10.1063/1.4914475

Rajesh K Katiyar, Ram S Katiyar + Show 8 more

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https://doi.org/10.1063/1.4914475

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Abstract

We report unipolar resistive switching suitable for nonvolatile memory applications in polycrystalline BiFeO3 thin films in planar electrode configuration with non-overlapping Set and Reset voltages, On/Off resistance ratio of ∼104 and good data retention (verified for up to 3,000 s). We have also observed photovoltaic response in both high and low resistance states, where the photocurrent density was about three orders of magnitude higher in the low resistance state as compared to the high resistance state at an illumination power density of ∼100 mW/cm2. Resistive switching mechanisms in both resistance states of the planar device can be explained by using the conduction filament (thermo-chemical) model.

Highlights

The resistive random access memory (ReRAM) with its simple design, excellent scalability, high speed storage capacity, low power consumption, and semiconductor process flow compatibility has been identified by ITRS1 as a potential memory technology
We report unipolar resistive switching suitable for nonvolatile memory applications in polycrystalline BiFeO3 thin films in planar electrode configuration with nonoverlapping Set and Reset voltages, On/Off resistance ratio of ∼104 and good data retention
In this work we report the unipolar resistance switching in polycrystalline BFO thin films configured in planar electrode geometry and the photovoltaic response associated with the two resistance states

Summary

INTRODUCTION

The resistive random access memory (ReRAM) with its simple design, excellent scalability, high speed storage capacity, low power consumption, and semiconductor process flow compatibility has been identified by ITRS1 as a potential memory technology. Wang et al.[13] and Qu et al.[14] have observed bipolar resistance switching in BiFeO3/Nb-SrTiO3 heterojunctions with a contrast of ∼100 between the two resistance states and found substantial photovoltaic effect when the device was illuminated with white light. In most of these studies on resistive switching in BFO thin films, a metal-insulator-metal (MIM) type of structure with the insulating thin film sandwiched between two metallic electrodes was used and current-voltage measurements were done in top-bottom configuration. Our studies show that BFO thin films can simultaneously act as memory devices (resistive memory effect) as well as an efficient energy harvester (ferroelectric photovoltaic effect) when configured in planar geometry

EXPERIMENTAL

RESULTS AND DISCUSSION

CONCLUSIONS