Broadband WS2/WO3 Thin-Film Photodetector: A Step toward Next-Generation Optoelectronics

Photodetectors play a crucial role in advancing optoelectronic technologies. This study presents a unique WS₂/WO₃ heterostructure-based broadband photodetector fabricated using sputtering and CVD techniques and optimized through a high-temperature vacuum sulfurization process. Unlike earlier studies that limited WS₂/WO₃ junctions to UV–vis detection, this research is the first to extend their functionality into the NIR region, achieving an impressive responsivity of 1.933 A/W─one of the highest values reported for such heterostructures. The device exhibits outstanding performance from UV to NIR, with a detectivity of 7.3 × 10¹⁰ Jones, an EQE of 221%, NEP of 7.0 × 10^–14 W/Hz^1/2 and ultrafast response times (rise: 66 ms, decay: 73 ms). The superior photodetection capability is attributed to the type-II band alignment, enabling efficient charge separation. This innovative method establishes WS₂/WO₃ as a highly efficient broadband photodetector, making it suitable for applications in optical communication, medical imaging, and low-light vision.