Tetrahedral amorphous carbon resistive memories with graphene-based electrodes

TL;DR

This paper introduces graphene-electrode-based tetrahedral amorphous carbon resistive memories with high ON/OFF ratios, low power consumption, multiple resistive states, and potential applications in advanced computing architectures.

Contribution

It demonstrates polarity-independent ta-C resistive memory devices with graphene electrodes, achieving significantly higher resistance ratios and multi-bit storage capabilities compared to metal electrodes.

Findings

ON/OFF resistance ratio of ~4x10^5

Low power density of ~14μW/μm^2

Multiple resistive states enabling multi-bit storage

Abstract

Resistive-switching memories are alternative to Si-based ones, which face scaling and high power consumption issues. Tetrahedral amorphous carbon (ta-C) shows reversible, non-volatile resistive switching. Here we report polarity independent ta-C resistive memory devices with graphene-based electrodes. Our devices show ON/OFF resistance ratios$\sim$4x$10^5$, ten times higher than with metal electrodes, with no increase in switching power, and low power density$\sim$14$\mu$W/$\mu$m$^2$. We attribute this to a suppressed tunneling current due to the low density of states of graphene near the Dirac point, consistent with the current-voltage characteristics derived from a quantum point contact model. Our devices also have multiple resistive states. This allows storing more than one bit per cell. This can be exploited in a range of signal processing/computing-type operations, such as implementing logic, providing synaptic and neuron-like mimics, and performing analogue signal processing in non-von-Neumann architectures