Two-Dimensional Material Applications in Memory Devices

In recent years, two-dimensional materials such as graphene, transition metal dichalcogenides (for example MoS₂ and WSe₂) and emerging layered compounds have become central to next-generation memory technologies. The atomically thin nature of these materials, combined with tunable electronic and optical properties, enables ultra-low-power operation, high integration density and mechanical flexibility beyond conventional silicon-based memories. By exploiting van der Waals heterostructures, designers can engineer pristine interfaces free of dangling bonds, yielding robust charge storage and high on/off ratios. Several device architectures have been demonstrated, including floating-gate memories, charge-trapping memories, resistive-switching memories and optoelectronic memories. In floating-gate configurations, monolayer semiconductors atop insulating layers such as hexagonal boron nitride store charges in adjacent two-dimensional layers, achieving retention times extending to years and multilevel storage states. Resistive-switching memories harness ion migration or phase transitions in 2D crystals to create low-voltage, ultrafast non-volatile cells. Meanwhile, optoelectronic memory devices integrate light-sensitive layers with charge-trapping functionalities to realise in-memory sensing and neuromorphic visual processing. Collectively, these approaches address the speed–retention–endurance trade-off of flash memory, offering nanosecond switching, high cycle counts and enhanced data throughput. The global significance of these advances spans data-centre storage, wearable electronics and edge-computing, where the synergy of storage and logic at the material level promises reduced energy consumption and novel computational paradigms.

Research from Nature Portfolio

Recent studies have achieved ultrafast and robust two-dimensional flash memory devices by engineering edge contacts in van der Waals heterostructures. By replacing conventional top contacts with metallic phase-engineered edge contacts on MoS₂ channels, programme and erase operations reach tens of nanoseconds while maintaining retention beyond ten years and endurance over one million cycles. This demonstrates that contact geometry and phase selection can overcome the speed–retention–endurance dilemma in non-volatile memory. Another development has introduced a threshold-switching layer of graphdiyne oxide within a MoS₂/hBN/MoS₂/graphdiyne oxide/WSe₂ stack to enable direct charge injection at low voltage. Nanosecond voltage pulses as low as 2 V inject charges directly into the floating gate, yielding ultralow energy consumption (~10 fJ) and decade-long retention. This approach replaces high-voltage tunnelling mechanisms with a volatile switching layer, unlocking high-speed, low-power non-volatile storage.

Two-Dimensional Material Applications in Memory Devices publication trend

The graph below shows the total number of articles in two-dimensional material applications in memory devices across all publications each year (not limited to Nature Index journals).

Technical terms

Van der Waals heterostructure: A stack of two-dimensional materials held together by weak interlayer forces, enabling clean interfaces and novel device functionalities.

Floating gate memory: A non-volatile architecture in which a conductive layer traps and holds charge to represent stored data.

Charge trapping: The process by which injected carriers are captured in localized states within a dielectric or semiconductor layer.

Schottky barrier: The energy barrier for carrier injection at a metal–semiconductor interface, influencing device speed and retention.

Retention: The ability of a memory cell to maintain stored information over time without power.

References

1. Simultaneously ultrafast and robust two-dimensional flash memory devices based on phase-engineered edge contacts. Nature Communications (2023).
2. Low-voltage ultrafast nonvolatile memory via direct charge injection through a threshold resistive-switching layer. Nature Communications (2022).
3. Artificial visual perception neural system using a solution-processable MoS2-based in-memory light sensor. Light: Science & Applications (2023).
4. Direct Charge Trapping Multilevel Memory with Graphdiyne/MoS2 Van der Waals Heterostructure. Advanced Science (2021).