Dielectric response of Au/(Co:PVA)/n-Si/Al structures under varying frequencies and bias voltages

This study presents a comprehensive analysis of the frequency and voltage-dependent behavior of key electrical parameters, including the real and imaginary components of complex dielectric permittivity (epsilon ', epsilon ''), electric modulus (M ', M ''), impedance (Z ', Z ''), loss tangent (tan delta), AC conductivity (sigma ac), and phase angle (theta) in Au/(Co: PVA)/n-Si/Al structures. To achieve this, impedance and dielectric measurements were conducted across a frequency range of 1 kHz to 1 MHz and a voltage range of - 3.5 V to 2 V. The results indicate that all examined parameters exhibit significant dependence on frequency and voltage, particularly at low to moderate frequencies within the depletion region. This behavior is primarily attributed to the influence of interface traps (Nit), their relaxation lifetimes (tau), and Maxwell-Wagner polarization effects. These factors contribute to distinct variations and splitting in the epsilon ', epsilon '', M ', M '', Z ', Z '', and sigma ac curves as functions of voltage and frequency. Additionally, observed peaks and shifts in these parameters are linked to the redistribution and reconfiguration of interface traps and polarization mechanisms under applied electric fields. Notably, the high dielectric constant (epsilon ' approximate to 10.5) measured even at 1 kHz suggests that the Co: PVA interfacial layer holds promise as a viable alternative to conventional insulating materials in future electronic and dielectric applications. Furthermore, Nyquist plots revealed a single semicircular arc, indicative of a Debye-type single relaxation process in the structure.