The fabrication of Au/(nanographite-PVP)/n-Si (MPS) structures and investigation of their electrical and dielectrical properties in a wide range of frequency and voltage

In this thesis study, the frequency response on profile of C-V-ƒ and G/ω-V-ƒ characteristics of spin-coated nanographite (NG)-doped polyvinylpyrrolidone (PVP)/n-Si structures in a wide frequency (1kHz-5MHz) and voltage (±3V) ranges at room temperature. Hereby, the basic parameters of the structure such as diffusion potential (VD), doping donor density (ND), Fermi energy level (EF), maximum electric field (Em), depletion layer thickness (Wd), and barrier height (ΦB) are derived by using the intercept and slope of C-2-V-ƒ plot for each frequency. Additionally, the energy density distribution of surface states (Nss) and their relaxation time values (τ) are also obtained from the conduction method. The lower Nss values are the consequence of passivation effect of the used nanographite (NG)-PVP polymer interlayer. In the Au/NG-PVP/n-Si MPS structures, which are examined in scope of dielectrical properties, the consequences of applying (NG-PVP) interlayer on surface states (Nss), series resistance (Rs), and polarization effects on the real and imaginary parts of the complex dielectric constant (ε*), loss-tangent tanδ, electrical-conductivity (σ), and complex electric-modulus (M*) have been investigated in -1V and +2V voltages and in the same frequency voltage. Additionally, the frequency-dependent profile of both Rs and complex-impedance (Z*) were extracted by using the ε' and ε″ values. The observed peak characteristics in M″ and tanδ versus V and frequency plots was attributed to relaxation-time and spatial distribution of Nss located at interlayer/n-Si interface, interfacial/dipole polarization. Owing to lowering Nss, surface dislocations and having high dielectric value (6,5), NG-PVP becomes a very proper candidate instead of commonly used oxide/insulator layers for this purpose.