The Frequency Dependent of Main Electrical Parameters, Conductivity and Surface States in the Al/ (%0.5 Bi:ZnO)/p-Si/Au (MIS) Structures

The capacitance/conductance-voltage-frequency (C/G-V-f) features of the Au/p-Si structures with (%0.5 Bi-doped ZnO) interlayer grown by spin-coating technique was investigated between 100 kHz and 1 MHz. The C⁻²-V curves that depend on frequency were used to determine the electrical-parameters like diffusion-potential (V_D), Fermi-energy level (E_F), barrier-height (Φ_B), and depletion-layer (W_D) thickness. The value of Φ_B was found to increase with increasing frequency due to the decrease in surface-states (N_ss) effects on the C-V characteristics. Voltage dependent series-resistance (R_s) was obtained by using Nicollian-Brews method for each frequency and it decreased with increasing frequency. Both the low-high frequency capacitance (C_LF-C_HF) and Hill-Coleman techniques were used to determine the voltage-dependent profile of N_ss. While N_ss decreases with increasing frequency, voltage-dependent on them give two distinctive peaks due to a special distribution of them at interlayer/semiconductor interface in the bandgap depending on their relaxation time. All these experimental results indicate that the existence of R_s, N_ss, and interlayers considerably influence the impedance measurements.