Dipole-Driven Charge Trapping in Monolayer Janus MoSSe for Ultrathin Nonvolatile Memory Devices

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Electronics

Background:

• Conventional flash memory scaling faces limitations in speed, data retention, and defects.
• Two-dimensional (2D) materials offer potential solutions due to their unique properties like van der Waals interfaces and atomic thickness.

Purpose of the Study:

• To develop a nonvolatile 2D flash memory device utilizing Janus MoSSe and hexagonal boron nitride (h-BN).
• To investigate the impact of Janus MoSSe's intrinsic asymmetry on charge trapping and device performance.

Main Methods:

• Fabrication of a 2D flash memory device with monolayer Janus MoSSe as the charge-trapping layer.
• Integration of hexagonal boron nitride (h-BN) as an ultrathin tunneling barrier.
• Characterization of device performance, including retention, endurance, memory window, and charge-trapping rates.

Main Results:

• Janus MoSSe exhibits enhanced charge trapping and deeper energy barriers due to its vertical dipole moment.
• Devices demonstrated excellent retention (>10^4 s) and endurance (>10^4 cycles).
• Achieved large memory window ratios (50%-70%) and high charge-trapping rates (up to 8.96 × 10^14 cm^-2 s^-1).
• Demonstrated synaptic characteristics and successful recognition simulations in artificial neural networks.

Conclusions:

• Janus MoSSe is a promising material for high-performance 2D nonvolatile memory.
• The device design enables ultrathin, flexible, and energy-efficient memory applications.
• Establishes a new design paradigm for advanced 2D memory devices.