Influence of Polymer Matrix Polarity on Dielectric Relaxation and AC Conduction in Silicon–Polymer Thin Composites

ABSTRACT

This study examines the influence of polymer matrix polarity on dielectric relaxation and alternating‐current conduction in thin silicon–polymer composite films. Two systems containing equal volume fractions of p‐type monocrystalline silicon and polymer were compared: silicon–polyvinylidene fluoride and silicon–polypropylene. Dielectric permittivity, dielectric loss, relaxation behavior, and electrical conductivity were analyzed over broad frequency and temperature ranges. Both composites exhibited relaxation‐type dielectric dispersion and frequency‐dependent conductivity consistent with Jonscher's universal power law. The silicon–polyvinylidene fluoride composite showed higher dielectric permittivity, stronger dielectric loss, and a pronounced relaxation maximum, reflecting enhanced dipolar response and Maxwell–Wagner–Sillars interfacial polarization. In contrast, the silicon–polypropylene composite displayed lower dielectric response, higher activation energies, and stronger temperature dependence of the frequency exponent. These differences indicate that the polar matrix promotes interfacial charge accumulation and localized charge displacement, whereas the non‐polar matrix favors barrier‐controlled hopping transport. Arrhenius analysis confirmed thermally activated conductivity and relaxation processes in both systems. The results demonstrate that polymer polarity governs the balance between polarization and conduction mechanisms in silicon–polymer thin composites and may guide the design of functional dielectric layers, sensor‐related components, and insulation materials. The comparison provides a basis for selecting polymer matrices according to required dielectric performance and charge‐transport characteristics in devices.