Synthesis of highly crystalline needle-like silicon nanowires for enhanced field emission applications

Abstract

Needle-like silicon nanowires (SiNWs) were successfully synthesized on gold-coated silicon substrates using a very high frequency plasma enhanced chemical vapor deposition method (VHF-PECVD). The prepared samples were characterized by field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and photoluminescence (PL). XRD analysis confirmed formation of single crystalline SiNWs along (111) crystalline planes and microscopic studies revealed formation of NWs with diameters ranging from 10 to 100 nm and lengths of a few micrometers. Furthermore, the presence of gold nanoparticles on the tip of the NWs verified the vapor–liquid–solid growth mechanism of SiNWs. It was also demonstrated that SiNWs are composed of well-crystallized silicon cores and an amorphous shell. The obtained results verified potential application of such structures in field emission displays.