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

Abstract

AC electrical conductivity (σac), 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 30–106 Hz. It is observed that σac increases as frequency increases with a higher slope in the medium frequency (<105Hz) 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 104Hz 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 (<102Hz) and then it decreases slightly with a broad minimum at 103 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