Robust trap effect in transition metal dichalcogenides for advanced multifunctional devices

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Defects significantly influence the electrical transport properties of 2D transition metal dichalcogenides.
• Defect-induced deep traps can capture charge carriers, but their instability and lack of control have limited applications.
• Previous research often focused on mitigating trap effects rather than utilizing them.

Purpose of the Study:

• To realize a stable and controllable trap effect in 2D materials for electronic applications.
• To explore the potential of defect engineering in MoS_2xSe_2(1-x) for infrared detection and memory.
• To leverage the synergistic effects of defects for enhanced device performance.

Main Methods:

• Fabrication of two-dimensional MoS_2xSe_2(1-x) alloys.
• Introduction of sulphur vacancies and incorporation of selenium atoms to create synergistic defect sites.
• Characterization of carrier trapping and storage capabilities.
• Fabrication and testing of infrared photodetectors and nonvolatile memory devices based on the engineered material.

Main Results:

• Achieved a robust carrier trap effect in 2D MoS_2xSe_2(1-x) through defect engineering.
• Demonstrated high photoresponsivity (2.4 × 10⁵ A/W) and photoswitching ratio (~10⁸) for infrared detection.
• Realized nonvolatile infrared memory with a high program/erase ratio (~10⁸) and fast switching times.
• Utilized an individual flake for both detection and memory functionalities.

Conclusions:

• Synergistic defect engineering in 2D MoS_2xSe_2(1-x) enables stable carrier trapping.
• This approach opens new avenues for developing high-performance infrared detectors and nonvolatile memory devices.
• The ability to harness defect properties offers a promising strategy for future nanoelectronic applications.