On the frequency and (ZnCdNiTiO2) nanocomposite interlayer effects on electrical parameters and conduction mechanism in Al/(ZnCdNiTiO2)/p–Si (MIS) structures

In this study, Al/p–Si Schottky-based diodes with a (ZnCdNiTiO₂) nanocomposite-interlayer were constructed to investigate the effects of frequency, voltage, and interlayer on the electrical characteristics and conduction mechanisms (CMs). For this purpose, impedance– voltage–frequency (Z–V–f) measurements of the Al/(ZnCdNiTiO₂)/p–Si (MIS) structures were performed over a wide frequency range (1 kHz–1 MHz) and voltage range (± 2.5 V). The experimental findings show that both the fundamental electrical parameters and the conduction mechanism exhibit pronounced frequency and voltage dependent behavior, especially at low and moderate frequencies in the depletion region, attributed to interface-states (N_ss). In the accumulation regime, the response is dominated by series resistance (R_s) and the interlayer effects. These observations are consistent with the expected frequency response of the barrier and depletion characteristics, and the possible origins of N_ss and R_s were discussed. The parallel conductance and high-low frequency capacitance methods were applied to compute the voltage-dependent profile of N_ss, and their lifetimes (τ), while the Nicollian & Brews method was employed in the computation of R_s. The N_ss–V plot exhibits a distinct peak near 0.55 V, while τ decreases with increasing bias voltage. This behavior is attributed to a nonuniform distribution of N_ss within the semiconductor bandgap at the junction, with N_ss values on the order of ~ 10¹² eV⁻¹ cm⁻², as well as their restructuring-reordering under an electric field. These findings suggest that the ZnCdNiTiO₂ interlayer significantly influences the interfacial properties of Al/p–Si Schottky diodes and may offer useful insights for further optimization of Schottky-based MIS devices operating at different frequencies.