Defect-free SiC nanowires grown from Si-deposited graphite by thermal annealing: temperature-dependent nucleus formation and nanowire growth behaviors†
Herein, we introduce a facile growth method of catalyst- and defect-free SiC nanowires using a Si thin film as a Si source. Si thin films were deposited on graphite by radio frequency sputtering at room temperature. When they were thermally annealed at 1400 °C, single-crystalline 6H-SiC nanowires of tens of micrometers length were spontaneously grown on the surface of Si-deposited graphite. No catalyst residues and defects, such as metal tips and stacking faults, were observed in the as-grown SiC nanowires. The structural and morphological changes of the films as a function of annealing temperature were investigated to establish the growth mechanism of SiC nanowires. SiC nanowires were grown by the consecutive occurrence of two different mechanisms, the formation of SiC nuclei and the vapor–solid growth of SiC nanowires, which is dependent on the annealing temperature. Our study shows that the Si thin film is an attractive Si source from which to grow defect-free SiC nanowires and helps to develop the crystal growth technique of high-quality SiC for various applications such as in optoelectronics and power electronic devices.