Admittance behavior and dielectric loss mechanisms in Al/PANI–Silicene/n‑Si heterojunctions

Abstract Hybrid metal–polymer–two-dimensional (2D) semiconductor heterojunctions offer an effective platform for tailoring interface-controlled electrical and dielectric properties. In this study, Al/PANI–Silicene/n-Si Schottky diodes were fabricated and investigated using current–voltage, capacitance–voltage, admittance, and impedance spectroscopy over a wide frequency range. The devices exhibit clear rectifying behavior with an enhanced effective barrier height and reduced reverse leakage current, indicating relatively improved interface quality. Frequency-dependent measurements reveal strong dispersion in capacitance and dielectric loss at low frequencies, which gradually diminish at higher frequencies. Impedance and Nyquist analyses show a single dominant interfacial response, while modulus and dielectric representations indicate non-ideal relaxation behavior associated with a distributed spectrum of interface states. The extracted electrical parameters demonstrate that the incorporation of a Silicene interlayer significantly modifies the interfacial response of PANI-based Schottky junctions. These results provide a measurement-driven understanding of charge transport and dielectric behavior in polymer–2D–Si heterostructures and highlight their potential for advanced electronic device applications.