Voltage-frequency dependence of the complex dielectric and electric modulus and the determination of the interface-state density distribution from the capacitance-frequency measurements of Al/p-Si/Al and Al/V${}_2$O${}_5$/p-Si/Al structures

The energy distribution of the interface states (N${}_{ss}$) and relaxation time (τ) are calculated from the capacitance-frequency (C-f) characteristics for Al/p-type Si/Al metal-semiconductor and Al/V${}_2$O${}_5$/p-type Si/Al metal-interfacial layer-semiconductor diodes with and without anodic surface passivation. The experimental results show that the density of the interface states and the relaxation times increase almost exponentially with the bias from the top of the valence band to the center of the gap for each diode produced. At the same time, using the C-f characteristics, the dielectric properties such as the dielectric constant (ε'), dielectric loss (ε"), dielectric loss tangent (tanδ), real and imaginary portions of the electric modulus (M' and M") and ac electrical conductivity (σ${}_{ac}$) are investigated in this study. The analysis was performed at room temperature, in the frequency range from 1 kHz to 10 MHz, and the voltage range from 0 to 0.24 V. The experimental results show that the ε', ε" and tanδ values decrease with increasing frequency while σ${}_{ac}$, M' and M" values increase. This results will show that dielectric parameters are strongly frequency dependent.