High performance and gate-controlled GeSe/HfS₂ negative differential resistance device

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Transition metal dichalcogenides (TMDs) exhibit thickness-dependent current-voltage characteristics, enabling tunable threshold voltages.
• TMDs are crucial for developing negative differential resistance (NDR) devices essential for multi-valued logic.
• Van der Waals heterostructures (vdWHs) offer unique electronic properties due to controlled interfaces.

Purpose of the Study:

• To design and investigate a novel p-GeSe/n-HfS2 TMD vdWH NDR device.
• To analyze the NDR characteristics and understand the underlying current transport mechanisms.
• To demonstrate the potential of this vdWH diode in multi-valued logic applications, specifically as a ternary inverter.

Main Methods:

• Fabrication of a p-GeSe/n-HfS2 van der Waals heterostructure.
• Characterization of current-voltage (I-V) properties at room temperature.
• Analysis of tunneling and diffusion currents using a tunneling mechanism model.

Main Results:

• The designed p-GeSe/n-HfS2 vdWH device exhibited significant negative differential resistance (NDR).
• An extraordinary peak-to-valley current ratio (PVCR) of approximately 5.8 was achieved at room temperature.
• The device successfully functioned as a ternary inverter, demonstrating its multi-valued logic capability.

Conclusions:

• The p-GeSe/n-HfS2 vdWH NDR device represents a significant advancement in TMD-based electronics.
• The observed NDR characteristics are well-explained by tunneling mechanisms.
• This heterostructure holds potential for high-performance, multifunctional electronic devices, particularly for multi-valued logic.