Coupled polarization dynamics and charge tunneling enable reconfigurable heterojunctions

Area of Science:

• Materials Science
• Condensed Matter Physics
• Device Engineering

Background:

• Layered CuInP₂S₆ offers ferroelectric properties for neuromorphic devices but has limitations in tunability.
• Single-mechanism control in CuInP₂S₆ hinders large-scale complementary logic and heterogeneous integration.

Purpose of the Study:

• To create a ferroelectric heterostructure that combines ferroelectric polarization and charge tunneling for enhanced device performance.
• To enable nonvolatile memory operation with improved on/off ratios, endurance, and multilevel state retention.

Main Methods:

• Fabrication of a novel ferroelectric heterostructure.
• Characterization of device performance including on/off ratio, endurance, and retention.
• Exploitation of the interplay between polarization and tunneling for device control.

Main Results:

• Achieved nonvolatile memory with an on/off ratio > 10⁶, endurance up to 10⁵ cycles, and 16 distinct memory states retained for > 10³ s.
• Demonstrated controllably reconfigurable adjustment and a high diode rectification ratio.
• Realized multimode regulation of junction configurations (nn, np, pp, pn) and logic-in-memory functionality within a single cell.

Conclusions:

• The coupled polarization dynamics and tunneling effect in the heterostructure lead to high integration, energy efficiency, and multifunctionality.
• This approach effectively reduces circuit complexity for next-generation intelligent computing, sensing, and edge applications.
• The developed device shows promise for advanced neuromorphic and edge computing systems.