# Structure and Electrical Properties of Carbon-Rich Polymer Derived Silicon Carbonitride (SiCN)
## 4 Conclusions  
The structure and electronic properties of carbon-rich polymer-derived SiCN (up to ca. 72 at. % carbon) heat-treated in an argon atmosphere at 1100-1600 \({}^{\circ}\)C are herein investigated and reported. The electrical properties of the C/SiCN nanocomposites examined using Hall measurement demonstrated an anomalous change in the majority charge carriers from n-type in the samples pyrolyzed at 1100 \({}^{\circ}\)C to p-type in the samples prepared at T \(\geq\) 1400 \({}^{\circ}\)C. Moreover, it was found that RT conductivity of the materials produced at 1000-1600 \({}^{\circ}\)C increased from 0.148 S/cm to 9.26 S/cm which are much higher than the previously reported values for monolith samples produced using similar pyrolysis and annealing temperature. Both the anomalous shift in predominant carriers and high electrical conductivities are attributed to the preliminary quantity of carbon content and evolution of the sp\({}^{3}\) to sp\({}^{2}\) hybridized carbon transformation as the processing temperature increases. Furthermore, parameters associated with the sp\({}^{3}\) to sp\({}^{2}\) transition in the carbon-rich SiCN structure investigated using Raman spectroscopy such as:the crystallite size (L\({}_{\mathrm{a}}\)), average continuous graphene length including tortuosity (L\({}_{\mathrm{eq}}\)), and inter-defect distance (L\({}_{\mathrm{D}}\)) all increased with an increase in processing temperatures. Interestingly, the stacking  
Figure 5: Hall measurement performed in 10 repetitions on the C/SiCN nanocomposites showing the shift in predominant charge carriers from n-type at 1100 \({}^{\circ}\)C to p-type at higher temperatures \(\geq\) 1400 \({}^{\circ}\)C: (**a**) Hall coefficients at 1100 \({}^{\circ}\)C showing n-type carriers; (**b**) Hall coefficients of the sample prepared at 1400 \({}^{\circ}\)C showing p-type carriers; (**c**) Hall coefficients of the carbon rich SiCN prepared at 1600 \({}^{\circ}\)C showing p-type carriers.  
number of graphene layers (L\({}_{\rm c}\)) of the graphitic carbon phase was found to contain mono to three layers of graphene across all adopted processing temperatures. Depending on the phase composition and processing conditions, custom-made carbon-rich SiCN polymer-derived ceramics could be developed to produce n-type and p-type semiconductors for the development of the future generation of micro-electromechanical systems (MEMS), heterojunction diodes and other electronic devices for applications in extremely high temperature environments.  
Conceptualization, O.D.A. and E.I.; Formal analysis, O.D.A.; Investigation, O.D.A.; Methodology, O.D.A., E.R.III and E.I.; Resources, E.I.; Supervision, A.A.D., L.E.U. and E.I.; Writing--original draft, O.D.A.; Writing--review & editing, O.D.A., E.R.III, A.A.D., L.E.U. and E.I. All authors have read and agreed to the published version of the manuscript.  
Financial support from the Tertiary Education Trust Fund, TETFUND towards the success of the experiment is acknowledged and duly appreciated.  
Not applicable.  
The authors declare no conflict of interest.