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

Abstract

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 ZnTiO 3 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-ZnTiO 3 /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:ZnTiO 3 /p-Si (MPS3) SDs, respectively. Therefore, doping Gr into the PVP interlayer increases the electrical conduction in the SDs although PVP:Gr-ZnTiO 3 polymer layer improves the RR of SDs.