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 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−1 (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 d without any encapsulation.