Stacking selected polarization switching and phase transition in vdW ferroelectric α-In₂Se₃ junction devices

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Ferroelectric domain walls are crucial for polarization switching in ferroelectric materials.
• Their behavior in two-dimensional (2D) ferroelectrics, like α-In2Se3, is not well understood.
• Engineering interlayer interactions by controlling stacking order can modulate ferroelectric properties.

Purpose of the Study:

• To investigate stacking-dependent ferroelectric domain walls in 2D α-In2Se3.
• To elucidate the resistance switching mechanism in ferroelectric semiconductor-metal junction devices based on α-In2Se3.
• To understand how different stacking orders (2H and 3R) influence domain wall dynamics and phase transitions.

Main Methods:

• Fabrication and characterization of ferroelectric semiconductor-metal junction devices using 2H and 3R stacked α-In2Se3.
• Electrical transport measurements to analyze resistance switching behavior and hysteresis windows.
• Analysis of domain wall dynamics and ferroelectric-paraelectric phase transitions under high electric fields.

Main Results:

• 3R stacked α-In2Se3 exhibits a large hysteresis window due to in-plane movement of out-of-plane domain walls.
• 2H stacked α-In2Se3 shows a small hysteresis window, favoring in-plane domain walls and out-of-plane motion.
• High electric fields induce phase transitions: 3R α-In2Se3 via intralayer gliding, 2H α-In2Se3 via bond dissociation and reconstruction.

Conclusions:

• Stacking configuration is a key factor in tuning ferroelectric domain wall properties in 2D α-In2Se3.
• This provides a new avenue for material engineering in ferroelectric devices.
• Understanding stacking-dependent domain wall dynamics is essential for designing high-performance ferroelectric devices.