Multidirectional Sliding Ferroelectricity of Rhombohedral-Stacked InSe for Reconfigurable Photovoltaics and Imaging...

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Sliding ferroelectricity in 2D materials offers advantages like ultra-thin thickness and high switching speeds.
• Understanding the link between sliding paths and polarization states in rhombohedral materials is crucial for 2D sliding ferroelectricity.
• Rhombohedral-stacked indium selenide (γ-InSe) is a promising material for exploring sliding ferroelectricity.

Purpose of the Study:

• To investigate layer-dependent multidirectional sliding ferroelectricity in rhombohedral-stacked InSe.
• To explore the relationship between sliding paths and polarization states in γ-InSe.
• To demonstrate the potential of γ-InSe for tunable photovoltaic and imaging applications.

Main Methods:

• Utilized dual-frequency resonance tracking piezoresponse force microscopy to study ferroelectric properties.
• Employed conductive atomic force microscopy to analyze electrical characteristics.
• Performed theoretical calculations to support experimental observations.

Main Results:

• Demonstrated layer-dependent multidirectional sliding ferroelectricity in rhombohedral-stacked InSe.
• Observed a tunable bulk photovoltaic effect in graphene/γ-InSe/graphene devices with a photovoltaic current density of ≈15 mA cm⁻².
• Experimentally observed dome-like domain walls attributed to multidirectional sliding-induced domains.
• Achieved high photoresponsivity (≈255 A W⁻¹) and fast response times for imaging.

Conclusions:

• Provides fundamental insights into the multidirectional sliding ferroelectricity of rhombohedral-stacked 2D materials.
• Highlights the potential of γ-InSe for advanced tunable photovoltaic devices.
• Confirms the suitability of γ-InSe for high-performance real-time imaging applications.