Frequency and voltage-dependent dielectric, electric modulus, and AC conductivity analysis of Au/NAMA/n-Si MIS diode structures

The dielectric response and electrical transport characteristics of an Au/NAMA/n-Si/In MIS-type diode structure were investigated in the frequency range of 10 kHz–1 MHz and voltage range of − 2 V to + 2 V. The NAMA organic interlayer was deposited onto the n-Si substrate by the spin-coating technique. Frequency-dependent capacitance and conductance measurements were used to determine the dielectric permittivity ( ε ′, ε ″), loss tangent (tan δ ), electric modulus ( M′ , M ″), and AC conductivity ( σ ac ) parameters of the fabricated structure. The obtained results reveal a strong frequency dispersion behavior associated with interfacial polarization and interface-related charge effects. The ε ′ values decrease with increasing frequency, while ε ″ and tanδ exhibit relatively high values in the low-frequency region due to dielectric loss mechanisms. Electric modulus analysis indicates the presence of relaxation processes and non-Debye type behavior within the structure. In addition, AC conductivity increases with frequency and reaches approximately 6⋅10 − 5 S/cm at 1 MHz. The results demonstrate that the NAMA interlayer significantly modifies the dielectric and electrical characteristics of the MIS structure and may provide potential advantages for frequency-dependent semiconductor device applications.