Effect of pyrolysis temperature on the electric conductivity of polymer-derived silicoboron carbonitride

The electric conductivity of polymer-derived SiBCNs pyrolyzed at different temperatures was studied. We showed that the boron impeded the graphitization of the free-carbon phase in the SiBCN, leading to a higher characteristic temperature and activation energy as compared to the SiCN. Such an impeding effect is due to the interaction between h-BN and graphite phase. We also provided a credible evidence to show that the increase in the electric conductivity of the SiBCN with pyrolysis temperature is likely due to the increase in the conductivity of the free-carbon phase.