Research Information System
International Journal of Modern Physics B, vol.39, no.28, 2025 (SCI-Expanded, Scopus)
The electrical and dielectric properties of an Au/MEH-PPV/p-Si/Al heterojunction were investigated using impedance spectroscopy. The impedance spectra revealed Cole–Cole-type relaxation with a fractal exponent (α) of 0.85, indicating nonideal charge dynamics modeled with a constant phase element. A remarkably high dielectric constant (ε′) of 45 was measured at 1kHz, highlighting the device’s potential for charge storage applications. At frequencies above 1MHz, the device exhibited negative capacitance (NC), a signature of dynamic inductive effects arising from charge carrier trapping and relaxation at the organic–inorganic interface. This behavior corresponds to an L–C resonance near 1MHz, which is also marked by a minimum in the dielectric loss (tan δ). These findings demonstrate that the device’s frequency response is governed by a complex interplay of interface states, dipole polarization and series resistance.