Thinnest Nonvolatile Memory Based on Monolayer h-BN.

Area of Science:

• Materials Science
• Nanoelectronics
• Solid-State Physics

Background:

• Two-dimensional (2D) materials are crucial for nanoelectronics.
• Previous research suggested atomically thin layered materials couldn't achieve memristive effects in vertical structures.
• Monolayer transition metal dichalcogenide (TMD) atomristors recently overcame sub-nanometer scaling limits.

Purpose of the Study:

• To report the nonvolatile resistance switching (NVRS) phenomenon in monolayer hexagonal boron nitride (h-BN).
• To investigate h-BN atomristors for potential applications in next-generation electronic devices.
• To explore the underlying mechanism of resistance switching in 2D insulators.

Main Methods:

• Fabrication and characterization of monolayer h-BN atomristors with various electrodes.
• Electrical testing of NVRS in unipolar and bipolar operations.
• Ab-initio simulations to elucidate the switching mechanism.

Main Results:

• Monolayer h-BN exhibits forming-free NVRS with a large on/off ratio (up to 10^7).
• Fast switching speeds (<15 ns) were achieved via pulse operation.
• h-BN atomristors achieved a record thickness of ≈0.33 nm, surpassing monolayer TMDs.
• Simulations suggest metal ion substitution into h-BN vacancies drives the switching.

Conclusions:

• Monolayer h-BN is a viable 2D insulator for nonvolatile memory applications.
• The NVRS phenomenon in h-BN arises from defect, metal ion, and interface interactions.
• These findings pave the way for ultrathin flexible memory, printed electronics, neuromorphic computing, and RF switches.