Polarization-Sensitive Detector Based on MoTe₂/WTe₂ Heterojunction for Broadband Optoelectronic Imaging

Area of Science:

• Materials Science
• Optoelectronics
• Condensed Matter Physics

Background:

• Polarization-sensitive detectors are crucial for modern communication and information processing.
• Transition metal dichalcogenide (TMD) heterojunctions offer unique optoelectronic properties.
• Developing efficient and broadband photodetectors remains a key challenge.

Purpose of the Study:

• To present a novel polarization-sensitive detector based on a Molybdenum Ditelluride (MoTe₂)/Tungsten Ditelluride (WTe₂) heterojunction.
• To investigate the performance of this heterojunction for wide spectral detection.
• To evaluate its potential for polarization-sensitive applications.

Main Methods:

• Fabrication of a MoTe₂/WTe₂ heterojunction.
• Characterization of the heterojunction's structural and electronic properties.
• Measurement of photoelectric response, responsivity, detectivity, photoswitching ratio, and polarization sensitivity under varying wavelengths and zero bias.

Main Results:

• The MoTe₂/WTe₂ heterojunction exhibits enhanced carrier separation and photoelectric response.
• Wide spectral detection from visible to near-infrared light was achieved.
• High responsivity (0.6 A/W) and detectivity (3.6 × 10¹³ Jones) were obtained at 635 nm.
• A large photoswitching ratio (6.3 × 10⁵) and significant polarization sensitivity (3.5 at 635 nm, 5.2 at 1310 nm) were demonstrated at zero bias.

Conclusions:

• The MoTe₂/WTe₂ heterojunction is a promising candidate for high-performance polarization-sensitive detectors.
• This work provides valuable insights for designing advanced optoelectronic devices.
• The demonstrated device capabilities highlight potential in optical communication and information processing.