High on/off ratio photosensitive field effect transistors based on few layer SnS2

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) layered tin disulfide (SnS2) nanosheets exhibit unique anisotropic properties.
• Research interest in 2D SnS2 is growing due to its potential in electronic and optoelectronic applications.

Purpose of the Study:

• To fabricate few-layer SnS2 nanosheets via mechanical exfoliation.
• To investigate the structural, electronic, and optical properties of these 2D SnS2 materials.
• To fabricate and characterize a photosensitive field-effect transistor (FET) based on SnS2 nanosheets.

Main Methods:

• Mechanical exfoliation of bulk SnS2 to obtain few-layer nanosheets.
• Micro-characterization techniques (e.g., microscopy) and Raman spectroscopy to analyze structure.
• Fabrication of a field-effect transistor (FET) device.
• Electrical and photoresponse measurements of the FET.

Main Results:

• Few-layer SnS2 nanosheets with hexagonal symmetry were successfully fabricated.
• Comparative investigation of energy band structures for bulk and monolayer SnS2.
• Fabricated SnS2 FET exhibited high photosensitivity with an on/off ratio of 10^3.
• Achieved responsivity of 8.5 A/W and external quantum efficiency (EQE) of 1.2 × 10^3%.

Conclusions:

• The study successfully demonstrates the fabrication of high-quality 2D SnS2 nanosheets.
• The developed SnS2-based photosensitive FET shows promising performance for optoelectronic applications.
• These 2D SnS2 materials hold potential for future functional electronic and optoelectronic devices.