Effect of surface bond and quantum confinement effect on photoluminescence properties of SiC nanowires in different solvents.

Two kinds of SiC nanowires exhibiting different structures were fabricated by carbothermal reduction method and subsequent wet chemical etching. Strong and tunable ultraviolet to green emission peaks emerged in the photoluminescence spectra of both kinds of SiC nanowires in water and ethanol suspensions with the increase of excitation wavelength from 260 nm to 480 nm. The strong and distinctive ultraviolet emission originates from the quantum confinement effect of the nanoplatelets with a thickness less than 3 nm and the effects of Si–OH and Si–OR (R: ethoxy group) on the SiC nanowire surface. The blue emission derived from the SiC nanowires in different solvents is due to the combined effect of the nanoplatelet thickness, which meets the theoretical prediction value (3–5.4 nm), and surface bonds. The weaker green emission can be attributed to the large SiC nanowires and surface bonds caused by Si–OR and Si–OH. [ABSTRACT FROM AUTHOR]