Significant enhancement of the dc transport for the SiC-polymer nanocomposites

The complex studies of dc-conductivity were done for the 1,4-cis-polibutadien polymer films with embedded SiC nanocrystals (5% in weighting units). The averaged sizes of the SiC nanocrystallites were equal to about 20 nm. The investigations were done versus the film thickness, temperature and electric field strength to study an origin of the mechanisms determining the temperature dc-conductivity dependences. The current was varied between 10−12 and 10−4 A. The films with thickness 1–12 μm were studied both for the pure polymers as well as for those doped by SiC. The applied electric field strengths were varied up to 3×107 V/m in the temperature range 15–325 K. It was established that the principal role for dc transport properties are played by polymer phase states and content of SiC. The dominant mechanism for the observed dc-conductivity was described within a framework of Poole–Frenkel phenomenon and hopping. The activation energies were varied from kBT up to 0.36 eV.