Role of graphene nanoparticles on the electrophysical processes in PVP and PVP:ZnTiO3 polymer layers at Schottky diode (SD)

Abstract

In this paper, a polyvinyl pyrrolidine (PVP) polymer layer is inserted between the metal–semiconductor (MS) structure to manufacture a metal–polymer–semiconductor (MPS) structure or Schottky diode (SD). The zinc titanate and graphene nanostructures were doped into the PVP layer individually and together to improve the electrical performance of the MPS-type SD. The crystalline size, surface morphology, and band gap energy of the ZnTiO3 nanostructures are examined by the x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and ultraviolet–visible (UV–Vis) spectroscopy, respectively. It is common to measure the current–voltage (I–V) features (at ±3 V) of these five structures for calculating the reverse saturation current (I 0), barrier height, ideality factor (n), series (R s), and shunt (R sh) resistances as the main electrical parameters utilizing the thermionic emission, Norde, and Cheung models. Also, the forwarded-bias energy-dependent surface states density (N ss) and the forward/reverse biased current conduction mechanisms are studied and discussed. The rectifying ratio (RR) of Al/PVP:Gr-ZnTiO3/p-Si SD has the highest increase among these five SDs while the lowest I 0 and highest R sh are related to the Al/PVP:Gr/p-Si (MPS2) and Al/PVP:ZnTiO3/p-Si (MPS3) SDs, respectively. Therefore, doping Gr into the PVP interlayer increases the electrical conduction in the SDs although PVP:Gr-ZnTiO3 polymer layer improves the RR of SDs.