Tunable violet–blue emission from 3C-SiC nanowires

Bulk quantities of straight and curled cubic silicon carbide nanowires (3C-SiC NWs) are synthesized from the mixture of ZnS, Si, and C powders. The 3C-SiC NWs are wrapped by amorphous SiO2 shells with very thin thicknesses of less than 2.0 nm. The deionized water suspension of the as-made NWs shows a photoluminescence (PL) band centered at 548 nm, and a tunable violet–blue photoluminescence is observed as the excitation wavelength increases from 300 to 375 nm after the SiO2 shell is removed. The PL band at 548 nm relates to the SiO2 shell. Careful microstructural observation suggests that the tunable PL originates from the quantum confinement effect of 3C-SiC nanocrystallites with sizes of several nm at the turning of the curled NWs.