High-performance and highly stable self-powered photodetector based on electrospun RGO/MXene/PVA nanofiber/n-Si heterojunction

In this study, electrospun RGO/MXene/PVA hybrid nanofibers were developed using the electrospinning technique. The characteristics study of the prepared nanocomposite fibers was investigated using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared (FT-IR) spectroscopy, respectively. The hybrid nanofibrous network exhibited a continuous morphology and strong interfacial interactions between the polymer matrix and the 2D nanomaterials. A broadband self-powered photodetector based on an RGO/MXene/PVA nanofiber (NFs)/Si heterojunction was successfully fabricated and its optoelectronic performance was systematically investigated under white-light illumination and monochromatic irradiation at 365, 395, 590, and 850 nm. The device exhibited excellent photoresponse from the ultraviolet to the near-infrared region. Under white-light illumination, it achieved an ON/OFF ratio of 2.05 × 10⁵ at zero bias, demonstrating outstanding self-powered operation. Among the investigated wavelengths, the best performance was obtained at 590 nm, with a responsivity of 430 mA/W at −2.0 V, an ON/OFF ratio of 2.50 × 10⁵, and a detectivity of 1.54 × 1012 Jones at zero bias. Furthermore, the heterojunction exhibited an NPDR approaching 1010 W⁻¹ and a minimum NEP of ~10−14 W Hz⁻0.5 near zero bias. Moreover, the photodetector retained its excellent performance after 400 days, demonstrating outstanding long-term stability. These results demonstrate the strong potential of the proposed heterojunction for high-performance, low-noise, and self-powered broadband photodetection.