Self-powered stable high-performance UV-Vis-NIR broadband photodetector based on PVP-Cobalt@Carbon nanofibers/n-GaAs heterojunction

Abstract The self-powered PVP-Co@C nanofibers/n-GaAs heterojunction photodetector (HJPD) was fabricated by electrospinning of the PVP-Co@C nanofibers onto GaAs. An excellent rectification ratio of 6.60×106 was obtained from I-V measurements of the device in the dark. The I-V measurements of the fabricated device under 365 nm, 395 nm and 850 nm lights, as well as I-V measurements in visible light depending on the light intensity, were performed. The HJPD demonstrated excellent photodetection performance in terms of a good responsivity of ∼ 225 mA/W (at -1.72 V) and at zero bias, an impressive detectivity of 6.28×1012 Jones, and a high on/off ratio of 8.38×105, all at 365 nm wavelength. In addition, the maximum external quantum efficiency and NPDR values were 3495% (V=-1.72 V) and 2.60×1010 W-1 (V=0.0 V), respectively, while the minimum NEP value was ∼10-14 W.Hz-1/2 for 365 nm at V=0.V volts. The HJPD also exhibited good long-term stability in air after 30 days without any encapsulation.