Journal of Materials Science: Materials in Electronics, cilt.36, sa.29, 2025 (SCI-Expanded)
In the present study, Au/(Fe2O3)/n-Si SDs were created. Then, the frequency and voltage dependence of electrical parameters, surface states (Nss), and series resistance (Rs) were extracted from the impedance spectroscopy method (ISM) in a wide range of frequency (20 kHz–1 MHz) and voltage(± 3 V) to supply more accuracy and reliable results. The values of diffusion potential (VD), density of donor atoms (ND), barrier height (ΦB), depletion layer width and maximum electric field (WD, Em) were extracted from the linear part of the reverse-bias 1/C2 -V plot for each frequency, and they were found to be a strong function of frequency. These changes are more pronounced, especially at low–medium frequencies, and can be attributed to the Nss ability to easily follow the AC signal and polarization. Because in these frequencies, the lifetime (t) of Nss is higher than the measurement frequency (T = (2pf)−1), thus, it provides an excess contribution to both the measured C and G values. Additionally, both the voltage-dependent Nss and Rs profiles were extracted by using the admittance (Y = 1/Z) method developed by Nicollian-Brews and high-low frequency capacitance methods, respectively. The Nss vs. V plot shows a peak at around 0.60 V due to a specific distribution of Nss, their t, and the restructure/reordering of them under an electric field.