The voltage and frequency dependence of dielectric constant , dielectric loss , electrical modulus M , M , loss tangent tanδ and AC electrical conductivity σ AC of p-Si/ZnO/PMMA/Al, p-Si/ZnO/Al and p-Si/PMMA/Al structures have been investigated by means of experimental G-V and C-V measurements at 30 kHz, 100 kHz, 500 kHz and 1 MHz in this work. While the values of , , tanδ and σ AC decreased, the values of M and M increased for these structures when frequency was increased and those of p-Si/ZnO/Al and p-Si/PMMA/Al were comparable with those of p-Si/ZnO/PMMA/Al. The obtained results showed that the values of p-Si/ZnO/PMMA/Al structure were lower than the values of p