Interfacial Sb Sequestration-Expulsion Enabled by Homojunction-like Layered Structures for Multifunctional Memory

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Physics

Background:

• Elemental antimony (Sb) is crucial for ultrafast crystallization in phase-change materials.
• However, its poor amorphous stability limits device performance and data retention.

Purpose of the Study:

• To engineer a Sb/GaSb4 homojunction-like architecture for enhanced phase-change material stability.
• To investigate the role of interfacial engineering in regulating phase-change behavior and device performance.

Main Methods:

• Fabrication of Sb/GaSb4 homojunction-like structures with varying interfacial densities.
• Characterization of phase-change behavior, crystallization temperature, and data retention.
• Analysis of the interfacial sequestration-expulsion mechanism using advanced material analysis techniques.

Main Results:

• Increased interfacial density significantly elevated crystallization temperature and improved data retention.
• Preservation of layered structures and delayed crystallization were observed with higher interfacial density.
• An interfacial sequestration-expulsion mechanism was identified, stabilizing Sb-rich local environments.
• Devices demonstrated 5 ns switching, >10^5 endurance cycles, and low resistance drift.

Conclusions:

• Interface-engineered homojunction-like structures effectively mitigate phase-change trade-offs.
• The Sb/GaSb4 architecture enables high-speed switching, excellent endurance, and low resistance drift.
• Scalable interfacial density allows for linear conductance modulation, supporting both memory and neuromorphic applications.