Selective growth of zinc blende, wurtzite and hybrid SiC nanowires via a simple chemical vapor deposition route

Abstract

Although more than 250 polytypes of silicon carbide (SiC) crystals have been discovered, only very limited types of nanowires can be synthesized in a controllable manner. Both experimental and theoretical investigation reveal that 3C-SiC is the most stable form, which is the primary product of nanowires synthesized via various methods in thousands of reports. Although hexagonal phases, particularly the wurtzite structure with a bandgap of 3.33 eV is promising in optoelectronic applications, the fabrication of nanowires with theses phases is still rare. Herein, in this study, by precisely regulating the atmospheric conditions, we revealed that the CH₄ supply resulted in the phase-selective growth between 3C- and 2H-SiC nanowires. As the CH₄ flow rate increased, it was possible to fabricate 3C-SiC, hybrid 3C-/2H-SiC and 2H-SiC nanowires in a controllable manner. The possible mechanism is demonstrated accordingly. We believe this progress benefits the structural design and optoelectronic application of SiC nanowires.