Preparation and characterization of cross-linked poly (vinylalcohol)-graphene oxide nanocomposites as an interlayer forSchotty barrier diodes

Cross-linked polyvinyl alcohol (PVA) graphene oxide (GO) nanocomposites were prepared by simple solution-mixing route and characterized by Raman, UV visible and fourier transform infrared (FT-IR) spectroscopy analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The XRD pattern and SEM analysis showed significant changes in the nanocomposite structures, and the FT-IR spectroscopy results confirmed the chemical interaction between the GO filler and the PVA matrix. After these morphological characterizations, PVA-GO-based diodes were fabricated and their electrical properties were characterized using current voltage (I-V) and impedance-voltage-frequency (Z-V-f) measurements at room temperature. Semilogarithmic I-V characteristics of diode showed a good rectifier behavior. The values of C and G/w increased with decreasing frequency due to the surface/interface states (N-ss) which depend on the relaxation time and the frequency of the signal. The voltage, dependent profiles of N-ss and series resistance (Re) were obtained from the methods of high-low frequency capacitance and Nicollian and Brews, respectively. The obtained values of N-ss and R-s were attributed to the use of cross-linked PVA-GO interlayer at the Au/n-Si interface.