Tunable Gain SnS₂/InSe Van der Waals Heterostructure Photodetector

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional materials like SnS₂ and InSe offer unique electronic and optical properties.
• Combining SnS₂ (visible light spectrum energy gap) and InSe (high electron mobility) creates potential for advanced devices.

Purpose of the Study:

• To investigate a tunable gain SnS₂/InSe Van der Waals heterostructure photodetector.
• To characterize its performance under gate modulation for optoelectronic applications.

Main Methods:

• Synthesis of SnS₂ crystals using chemical vapor transport.
• Characterization via X-ray diffraction and Raman spectroscopy.
• Fabrication of the heterostructure photodetector and performance testing under gate modulation (0 V to +70 V).
• Simulation of light absorption and charge carrier generation using Silvaco TCAD software.

Main Results:

• Achieved photoresponsivity ranging from 14 mA/W to 740 mA/W.
• Achieved detectivity ranging from 2.2 × 10⁸ Jones to 3.35 × 10⁹ Jones.
• Experimental results were consistent with TCAD simulations of device physics.

Conclusions:

• The SnS₂/InSe heterostructure photodetector exhibits tunable gain and high performance in the visible spectrum.
• The demonstrated high responsivity and visible spectrum response suggest potential for commercial visible image sensors.