Comparison of the Electrical Response of Cu and Ag Ion-Conducting SDC Memristors Over the Temperature Range 6 K to 300 K.

Kolton Drake,Md Kamrul H Majumdar,Tonglin Lu,Kristy A Campbell

doi:10.3390/mi10100663

Abstract

Electrical performance of self-directed channel (SDC) ion-conducting memristors which use Ag and Cu as the mobile ion source are compared over the temperature range of 6 K to 300 K. The Cu-based SDC memristors operate at temperatures as low as 6 K, whereas Ag-based SDC memristors are damaged if operated below 125 K. It is also observed that Cu reversibly diffuses into the active Ge2Se3 layer during normal device shelf-life, thus changing the state of a Cu-based memristor over time. This was not observed for the Ag-based SDC devices. The response of each device type to sinusoidal excitation is provided and shows that the Cu-based devices exhibit hysteresis lobe collapse at lower frequencies than the Ag-based devices. In addition, the pulsed response of the device types is presented.

Highlights

Self-directed channel (SDC) memristors are a type of chalcogenide-based electrochemical metallization (ECM) device [1,2,3,4,5,6,7] in which it is posited that re-usable and irreversible ion-transport channels are formed within the active chalcogenide layer during the first write operation [6,7]
There has been a trend in the literature to classify all ECM device types as conductively bridged random access memory (CBRAM) devices [4,21]
This generalization is in conflict with the earlier literature where CBRAM was used to describe a specific device type in which a conductive filament is formed through a solid solution, e.g., GexSe1-x where x < 0.33 [10,11,12,13,22,23,24,25,26,27,28,29,30,31]

Summary

Introduction

Self-directed channel (SDC) memristors are a type of chalcogenide-based electrochemical metallization (ECM) device [1,2,3,4,5,6,7] in which it is posited that re-usable and irreversible ion-transport channels are formed within the active chalcogenide layer during the first write operation [6,7]. There has been a trend in the literature to classify all ECM device types as conductively bridged random access memory (CBRAM) devices [4,21] This generalization is in conflict with the earlier literature where CBRAM was used to describe a specific device type in which a conductive filament is formed through a solid solution, e.g., GexSe1-x (or GexS1-x) where x < 0.33 [10,11,12,13,22,23,24,25,26,27,28,29,30,31]. Unlike the GeSe-Ag CBRAM device, the SDC device structure contains material layers meant to store metal ions (the SnSe layer or other metal-chalcogenide layer—see [7] for experimental data and a discussion of the effects of the metal on SDC operation) and to facilitate fast switching; these are not present in the GeSe-Ag solid solution-based device

Methods

Results

Discussion

Conclusion