Fabrication of electrical semi-conductive SiCN ceramics by vat photopolymerization

Abstract

The emergence of additive manufacturing (AM) enables ceramics to be fabricated with customized geometry, and polymer-derived ceramics (PDCs) has attracted growing attention owing to their irreplaceable advantages. The combination of 3D printing and PDCs endows the resultant ceramics with both precision and performance. However, AM of ceramics from preceramic polymers is still challenging, and insufficient investigation of functionality also limits the versatility of precursor and its derived ceramics. Herein, we propose a novel paradigm for 3D printing dense silicon carbonitride ceramic and study its electrical semi-conducting properties. The formulated photosensitive precursor inks could achieve self-polymerization and cross-linking under the radiation of UV light (405 nm). The green body with intricate structures is fabricated by digital light processing (DLP). Lightweight (1.79–2.08 g cm–3) and low porosity (< 5%) amorphous ceramics were obtained after thermal treatments. Processes of cross-linking, decomposition, and ceramization are monitored and analyzed. Furthermore, the semi-conducting behaviors of resultant ceramics are identified where the conductivity (10–5–10–1 S m–1) has a monotonic correspondence with the testing temperatures (25–1000 °C). The numerical relationship is fitted by exponential functions, and its conducting mechanism could be interpreted by the band tail hopping (BTH) model. This work could provide alternative solutions for the fabrication of PDCs and potentials for sensing applications.