Three-Terminal Multifunctional n-MoS₂/p-GaN Heterojunctions.

Area of Science:

• Materials Science and Engineering
• Optoelectronics
• Nanotechnology

Background:

• Developing multifunctional optoelectronic devices is crucial for advanced integrated circuits.
• Monolayer molybdenum disulfide (MoS2) and gallium nitride (GaN) offer unique electronic and optical properties.
• Heterojunctions with van der Waals (vdW) gaps enable novel device architectures.

Purpose of the Study:

• To demonstrate a reconfigurable, multifunctional optoelectronic device using an n-MoS2/p-GaN heterojunction.
• To leverage a third terminal for flexible control over device output characteristics.
• To integrate multiple functionalities, including photodetection and logic operations, into a single device.

Main Methods:

• Fabrication of a three-terminal device based on a monolayer n-MoS2/p-GaN heterojunction with a vdW gap.
• Characterization of the device's performance as a self-powered ultraviolet (UV) photodetector under two-terminal bias.
• Modulation of photocurrent using a third-terminal voltage and incident light for reconfigurable logic operations.

Main Results:

• The device functions as a self-powered UV photodetector with broad spectral response (visible and UV light).
• The third terminal enables flexible control, facilitating tunable photodetectors and optoelectronic logic gates (NAND, NOR).
• Demonstrated reconfigurable ternary and quaternary multivalued logic gates within the single device architecture.

Conclusions:

• The proposed three-terminal device offers a feasible strategy for designing reconfigurable optoelectronic systems.
• Integration of GaN and MoS2 advantages enables versatile functionalities in a single platform.
• Potential applications include artificial vision systems, low-power integrated circuits, and opto-electric interconnections.