All 2D WSe₂/MoS₂ heterojunction photodiode and its image sensor application

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) van der Waals atomic crystals possess unique properties.
• Their dangling-bond-free surfaces allow for unrestrained stacking to form heterostructures.

Purpose of the Study:

• To demonstrate a high-performance all 2D WS2/MoS2 heterojunction photodiode.
• To explore its potential in optoelectronic applications.

Main Methods:

• Fabrication of a WS2/MoS2 heterojunction photodiode using 2D materials.
• Integration of a graphene contact as an electrode.
• Characterization of electrical performance and spectral photoresponse.

Main Results:

• Achieved excellent electrical performance with an ideality factor of 1.2 and a rectification ratio of 10^4.
• Demonstrated a broad spectral photoresponse ranging from 450 to 980 nm.
• Exhibited remarkable linearity with a linear dynamic range of 113 dB.

Conclusions:

• The developed WS2/MoS2 heterojunction photodiode offers superior performance.
• A self-powered single pixel imager was successfully demonstrated, showcasing feasible optoelectronic applications.