# Structure and Electrical Properties of Carbon-Rich Polymer Derived Silicon Carbonitride (SiCN)
###### Abstract  
This article reports on the structure and electronic properties of carbon-rich polysilazane polymer-derived silicon carbonitride (C/SiCN) corresponding to pyrolysis temperatures between 1100 and 1600 \({}^{\circ}\)C in an argon atmosphere. Raman spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Hall measurements were used to support the structural and electronic properties characterization of the prepared C/SiCN nanocomposites. A structural analysis using Raman spectroscopy showed the evolution of sp\({}^{2}\) hybridized carbon phase that resulted from the growth in the lateral crystallite size (L\({}_{\text{a}}\)), average continuous graphene length including tortuosity (L\({}_{\text{eq}}\)) and inter-defects distance (L\({}_{\text{D}}\)) with an increase in pyrolysis temperature. The prepared C/SiCN monoliths showed a record high room temperature (RT) electrical conductivity of 9.6 S/cm for the sample prepared at 1600 \({}^{\circ}\)C. The electronic properties of the nanocomposites determined using Hall measurement revealed an anomalous change in the predominant charge carriers from n-type in the samples pyrolyzed at 1100 \({}^{\circ}\)C to predominantly p-type in the samples prepared at 1400 and 1600 \({}^{\circ}\)C. According to this outcome, tailor-made carbon-rich SiCN polymer-derived ceramics could be developed to produce n-type and p-type semiconductors for development of the next generation of electronic systems for applications in extreme temperature environments. P claimClaim: Adding a carbonitride (SiCN), carbonitride (SiCN), semiconductor; free/sp\({}^{2}\)-hybridized carbon; nanocomposite  
Received: 25 August 2022  
Accepted: 27 September 2022  
carbon) [10; 11; 12]. The amorphous phase is associated with very low electrical conductivity (\(\sigma_{\rm dc}\)), in the range of 10\({}^{-9}\) to 10\({}^{-2}\) S/cm, but a vast increase of several orders of magnitude is observed as the material transforms to crystalline state via increase in pyrolysis temperature [13; 14]. Over the years, the strong increase in room temperature (RT) conductivity has been attributed to increase in pyrolysis temperature during thermal treatment of the material, which in turn leads to the following: (i) structural transformation of the carbon phase from amorphous carbon to ordered sp\({}^{2}\)-hybridized carbon (Note that the RT conductivity of sp\({}^{2}\) hybridized carbon is 10\({}^{\circ}\) to 10\({}^{5}\) S/cm); (ii) crystallization of \(\beta\)-SiC (Note that only SiC and sp\({}^{2}\)-hybridized carbon are semiconductors in the composition, Si\({}_{3}\)N\({}_{4}\) is an insulator and does not contribute to conductivity); and (iii) Nitrogen (N) doping of the \(\beta\)-SiC as Si\({}_{3}\)N\({}_{4}\) (in the SiC,/Si\({}_{3}\)N\({}_{4}\)/C nanocomposite) decomposes gradually to give off N\({}_{2}\) gas at higher temperatures when T \(>\) -1400 \({}^{\circ}\)C [9; 15]. While these assertions have been proven and corroborated by various characterization techniques such as XANES spectroscopy, XRD, TEM and Raman Spectroscopy, a profound understanding of the electrical conductivity of SiCN PDCs, particularly the charge carrier transport mechanisms, remain incomplete. Seeing the emerging potential of SiCN as semiconductor materials for the next generation of electronics for applications in extreme temperature environments, developing an understanding of the carrier transport mechanism is important in order to study the principle leading to its electrical conductivity as this could aid in their fabrication for various useful electronic purposes. Evaluation of the electrical conductivity of polysilazane-derived SiCN began in the early 90s with the work of [PERSON] but studies on their charge carrier transport are still very rare to come by in the literature [16; 17].