Tunable and nonvolatile multibit data storage memory based on MoTe₂/boron nitride/graphene heterostructures through...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Atomically thin two-dimensional (2D) materials enable advanced heterostructures for high-performance flash memory.
• Effective carrier modulation and unique interface charge trapping are key to 2D material memory devices.

Purpose of the Study:

• To report a nonvolatile floating-gate flash memory based on a MoTe2/h-BN/graphene van der Waals heterostructure.
• To demonstrate increased data storage capacity and versatile tunability in 2D material-based memory.

Main Methods:

• Fabrication of a van der Waals heterostructure device using Molybdenum Telluride (MoTe2), hexagonal Boron Nitride (h-BN), and graphene.
• Utilizing carrier tunneling through the h-BN dielectric layer for charge storage in the graphene floating gate.
• Applying varied gate bias to achieve multi-distinctive current levels for data storage.

Main Results:

• The MoTe2/h-BN/graphene heterostructure demonstrated nonvolatile flash memory behavior.
• The device achieved 2 bits per cell storage capacity by implementing multi-distinctive current levels.
• Observed a high erase/program current ratio of ~10^5 with a 1 µs switch speed and stable retention (~30% charge loss after 10 years).

Conclusions:

• The developed 2D heterostructure flash memory offers enhanced data storage capacity and tunable performance.
• The device's ability to operate in both p- and n-type modes through contact engineering broadens its applicability.
• This technology is suitable for emerging electronic applications, including neuromorphic computing and energy-efficient memory.