Effect of pyrolysis temperature on the structure and conduction of polymer-derived SiC

We studied the electric conductivity and structure of polymer-derived carbon-rich amorphous SiC pyrolyzed at different temperatures. The conductivity of the material increased drastically with pyrolysis temperature followed an Arrhenius relationship with the activation energy of ~3.4 eV. Raman and X-ray photoelectron spectroscopy analysis revealed that the order of free carbon phase increased with pyrolysis temperature, accompanied by sp³→ sp² transition. The activation energy for such a structure change was 3.1-3.8 eV, which is close to that for the conductivity change. We thus believe that the increase in the conductivity was mainly due to the increase in conductivity of the free carbon phase.