CuO NPs Blended WS2-QDs/Si (0D/3D) Vertical Heterojunction for Uniform and Spectrally Enhanced Broadband Photodetection

Abstract

Broadband photodetectors (i.e., sensing units) within the sensor node are a crucial component that plays a critical role in efficiently embedding cutting-edge technologies like the Internet of Things. Compared to other fabrication techniques, 2D layered material’s hybrid structure-based broadband photodetectors (PDs) may be more helpful in effectively deploying these technologies, as they can eliminate fabrication challenges such as complex device fabrication, low operating temperature requirements, and the toxic fabrication environment. Despite the above fabrication eases, the issue of nonuniform spectral response across the operating wavelength, adversely impacting PD efficacy, still needs to be addressed. The present work demonstrates a cost-effective and facile approach for achieving a substantially uniform spectral response across the broadband. The comparative investigation of WS₂-QDs-based PD fabricated with and without CuO NPs blending revealed that by blending WS₂-QDs with CuO NPs, the spectral response’s uniformity has been improved in addition to the quantitative improvement in the responsivity. The blended heterojunction PD structure demonstrated a broadband response between 365 and 950 nm at a low operating voltage of −1.5 V, with a peak responsivity of 111.84 A/W, EQE of 37993.74%, and detectivity of 2.13 × 10¹⁴ Jones. The PD’s temporal response was similarly found to be sufficiently fast, with rise and fall times of 40.83 and 39.76 ms, respectively.