Electrical characterizations of resistive random access memory devices based on GaV4S8 thin layers

The Mott insulator compound GaV4S8 exhibits resistive switching (RS) properties under electric pulses which could be used in the domain of data storage for future replacement of Flash technology. In this work, we present the characterization and the resistive switching performances of three devices containing GaV4S8 thin films with various electrode sizes and geometries, i.e. planar interdigit electrodes and Metal/Insulator/Metal Au/GaV4S8/Au structures. First, we evidence the good quality of the interfaces between GaV4S8 layers and gold electrodes through transmission electron microscopy observations which allows reliable electrical characterizations. Then, we demonstrate a downscaling effect as the resistive switching amplitude ΔR/R = (Rhigh − Rlow) / Rlow increases from a few percents to more than 600% as the electrode size decreases from 50 × 50 μm2 to 2 × 2 μm2. Finally we show that other performances such as cycling endurance, reaching more than 65,000 RS cycles, data retention time till 10 years or writing speed below 100 ns confirm the high potential of GaV4S8 as active material in future resistive random access memories or Mott memories.

► GaV4S8 performance towards memory application is studied on various electrode sizes.
► Endurance in GaV4S8 thin films reaches more than 65,000 cycles.
► We evidence writing/erasing times below 100 ns.
► Downscaling increases the resistance ratio of GaV4S8 Mott memories up to 600%.
► Retention time at room temperature is extrapolated to 10 years.