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

A key component of the transition metal dichalcogenides (TMDCs) family, tungsten disulfide (WS₂) offers exceptional optoelectronic characteristics and significant promise for high-sensitivity photodetection. This study utilized chemical vapor deposition (CVD) to grow WS₂ nanoflakes on a SiO₂/Si substrate. The WS₂/SiO₂/Si substrate was then coated with a thin layer of gold (Au) to create Au/WS₂ nanosheets. The resultant samples' crystalline structure and optical properties were investigated using Raman, UV-visible, and X-ray diffraction spectroscopies. Finally, we characterized the photodetectors' current and voltage under various power and wavelength settings. Following the deposition of the Au layer, the photodetector's responsivity, detectivity, and external quantum efficiency (EQE) all improved. Under a 635 nm laser with a power density of 10 mW/cm², the Au/WS₂ photodetector exhibited a high EQE of 138.91, a specific detectivity of 11 × 10¹⁰ Jones, and a responsivity of 71.09 mA/W. The current-time (It) measurement evaluates that Au/WS₂/SiO₂/Si photodetector responds better and at a faster response speed. Consequently, this hybrid material shows great potential for future optical device applications.