Thickness dependence of ac electrical conductivity and dielectric behavior of plasma polymerized 1, 1, 3, 3–tetramethoxypropane thin films

AC electrical conductivity ( σ ac ), dielectric constant ( ɛ ′), and dielectric loss tangent (tan  δ ) of plasma polymerized 1, 1, 3, 3‐tetramethoxy‐propane (PPTMP) thin films of thicknesses 100, 150, and 200 nm prepared by plasma polymerization technique using a capacitively coupled glow discharge reactor have been investigated in the frequency range of 30–10 6 Hz. It is observed that σ ac increases as frequency increases with a higher slope in the medium frequency (<10 5 Hz) region in the PPTMP thin films of three thicknesses. These observations suggest that the conduction may be dominated by hopping of carriers between the localized states. The general trend of ɛ ′ is to increase with increasing thickness, ɛ ′ remains independent of frequency upto about 10 4 Hz and then falls rapidly. The dependence of tanδ with frequency for PPTMP thin films of different thicknesses showed small relaxation peak at the very low frequencies (<10 2 Hz) and then it decreases slightly with a broad minimum at 10 3 Hz and again increases. Cole–Cole plot reveals that Debye type of mechanism is operative in the experimental frequency range. POLYM. ENG. SCI., 58:1342–1345, 2018. © 2017 Society of Plastics Engineers