Multilayer Graphene-Coated Silicon Carbide Nanowire Formation Under Defocused Laser Irradiation

• Published in: Nanomanufacturing and metrology 2023-12, Vol.6 (1), Article 21
• Main Authors: Minami, Kanon, Kobinata, Kyosuke, Yan, Jiwang
• Format: Article
• Language: English
• Subjects: Engineering; Machines; Manufacturing; Nanotechnology; Nanotechnology and Microengineering; Original Article; Processes
• ISSN: 2520-811X; 2520-8128
• DOI: 10.1007/s41871-023-00203-8

Graphene-coated silicon carbide (SiC@C) core–shell nanostructures have attracted attention in the fields of energy storage and nanoelectronics. In this study, multilayer graphene-coated silicon carbide (SiC) nanowires were obtained through the laser irradiation of a mixture target of graphite powder and silicon (Si) grinding sludge discharged from Si wafer manufacturing. Laser irradiation was performed using an ytterbium (Yb) fiber pulsed laser with a pulse width of 10 ms and a wavelength of 1070 nm with various defocus distances. The effect of laser defocusing on the morphology of the generated nanostructures was investigated. Results showed that nanowires were produced under the defocused conditions, and nanoparticles were observed at the on-focus position. The products obtained under all defocused conditions showed a core–shell structure, and the SiC nanowires were covered by graphene layers. The aspect ratio of the nanowires increased with the defocus distance. Observation of the laser-induced plume using a high-speed camera showed that when the laser was defocused, the plume propagation speed slowed down, and the shape of the plume changed to a swirling vortex. The nanowire formation was closely related to the propagation speed and shape variation of the plume. This successful production of SiC@C core–shell nanowires from Si waste opens up the possibility of the sustainable development of new materials for energy storage and nanoelectronics. Highlights The shape of the produced nanostructures is changed from nanoparticles to nanowires by defocusing the laser beam. The SiC nanowires have core-shell structures and are covered by multilayer graphene. Under defocused conditions, the plume swirls as a vortex moving at a low speed, thus promoting nanowire growth.