High performance in the DC sputtering-fabricated Au/WS₂ optoelectronic device

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Tungsten disulfide (WS2) is a transition metal dichalcogenide (TMDC) with excellent optoelectronic properties.
• WS2 shows promise for developing high-sensitivity photodetectors.

Purpose of the Study:

• To investigate the performance enhancement of WS2-based photodetectors by incorporating a gold (Au) layer.
• To explore the potential of Au/WS2 hybrid nanosheets for optical device applications.

Main Methods:

• Chemical vapor deposition (CVD) was used to grow WS2 nanoflakes on a SiO2/Si substrate.
• A thin gold layer was deposited onto the WS2 nanoflakes to create Au/WS2 nanosheets.
• Raman, UV-visible, X-ray diffraction, and current-voltage measurements were employed for characterization.

Main Results:

• The Au/WS2 nanosheets exhibited improved crystalline structure and optical properties.
• Photodetectors fabricated with Au/WS2 demonstrated significantly enhanced responsivity, detectivity, and external quantum efficiency (EQE).
• Specifically, a 138.91 EQE, 11 × 10^10 Jones detectivity, and 71.09 mA/W responsivity were achieved under 635 nm laser illumination.

Conclusions:

• The integration of gold with tungsten disulfide nanoflakes effectively boosts photodetector performance.
• The Au/WS2 hybrid material shows great potential for next-generation optical sensing and device applications.
• The enhanced response speed and sensitivity make this material suitable for advanced optical applications.