The Electrical and Photodetector Characteristics of the Graphene:PVA/p-Si Schottky Structures Depending on Illumination Intensities

Abstract

Five samples were fabricated to obtain a diode with a PVA interface, both with and without graphene doping at different rates with high rectification in the dark. The electrospinning method was employed to apply the doped and undoped solutions, creating the interlayers. Since the diode with a 1 wt % graphene-doped PVA interlayer outperformed the other samples, the main electrical and photodetector characteristics of this structure were investigated. The electrical parameters of the diode were probed by the TE, Norde, and Cheung methods, and the parameters ( n and ϕ _B) acquired by both approaches were significantly influenced by illumination and voltages. The interface/surface state intensity values ( N _ss) were also calculated in the dark and under each illumination as a function of the band/energy gap depth ( E _ss– E _v). The time-dependent steady-state conditions and rise-decay behavior of the photocurrents during illumination were also investigated. Due to the high photocurrent values, the photosensitivity at zero bias is approximately 1.4 × 10 ⁴ at 100 mW cm ^–2. The responsivity and detectivity values appear to be altered significantly with changes in the illumination and voltage. Additionally, a double logarithmic plot of I _ph vs P reveals good linearity with slope values ranging from 0.5 to 1.