Single-Crystalline Pyramidal TiC_x Particles Grown by Biphase Diffusion Synthesis

In this study, we present single-crystalline pyramid-shaped (SP) TiCx particles synthesized on a stacked melt (copper)-solid (titanium) substrate using a biphase diffusion synthesis (BDS) method, in which different sizes ranging from nano- to micrometer scale were obtained within the copper melt with the {100} planes exposed to air. Direct observation and further plasma treatment of the pyramids at different self-assembly stages facilitated the investigation of their growth mode, especially in the horizontal plane. The dendritic growth mode along with the edge and corner-shared modes of the SP TiCx particles frozen on the copper surface was investigated. With SP TiCx particles stacked on top, MoS2-based phototransistors exhibited an up to 6-fold photocurrent increase under laser illumination at different wavelengths, which was attributed to the localized surface plasmonic resonance (LSPR) effect. The BDS method is applied for the synthesis of SP TiCx particles, with a detailed investigation of the relevant growth mode and related applications, such as decoration for high-performance photodevices.