High-Performance and Polarization-Sensitive Imaging Photodetector Based on WS₂ /Te Tunneling Heterostructure

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Next-generation imaging demands photodetectors with enhanced sensitivity, polarization sensitivity, miniaturization, and integration.
• Emerging 2D materials offer potential solutions, but current devices suffer from interfacial recombination, limited photoconductive gain, and poor photocarrier collection.

Purpose of the Study:

• To develop a high-performance imaging photodetector based on a 2D material heterostructure.
• To address the limitations of existing 2D photodetectors for practical imaging applications.

Main Methods:

• Fabrication of a tunneling-dominant imaging photodetector utilizing a WS2/Te heterostructure.
• Characterization of the photodetector's responsivity, detectivity, response time, and photocurrent anisotropy.
• Integration of the photodetector into polarized and ultra-weak light imaging systems.

Main Results:

• Achieved remarkable responsivity (402 A W⁻¹) and detectivity (9.28 × 10¹³ Jones).
• Demonstrated fast rise/decay times (1.7/3.2 ms) and a high photocurrent anisotropic ratio (2.5).
• Successfully showcased imaging capabilities in polarized and ultra-weak light systems.

Conclusions:

• The WS2/Te heterostructure photodetector exhibits excellent performance due to type-I band alignment and photoinduced tunneling.
• The device overcomes interfacial trapping, provides photoconductive gain, and enables anisotropic photocarrier collection.
• The demonstrated imaging capabilities highlight the promising application of this photodetector in future imaging systems.