High-performance nanocomposite polyvinylpyrrolidone (PVP)-Co@C fibers based heterojunction photodetector

We design and demonstrate a self-powered broadband photodetector based on PVP-Co@C nanofibers/n-Si heterojunction via electrospun of the nanofibers onto n-Si. The composite fiber was characterized in terms of its structural, morphological and chemical, properties by a wide range of analytical techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FTIR), respectively. Electrooptical measurements of the heterojunction device were analyzed in UV, Vis and IR region using current-voltage characteristics. Experimental results showed that the PVP-Co@C nanofibers/ n-Si heterojunction detector can operate in the UV-Vis-IR region with low power consumption even without the need for an external voltage. The device exhibited outstanding performance at zero bias such that the high on/off ratio of 1.35 & times; 105 and detectivity of 2.87 & times; 1011 Jones, respectively for 590 nm illumination. Besides, its UV detectivity and EQE reached as high as 2.72 & times; 1011 Jones (zero bias) and 516 (%) (at -2.0 V), respectively.