Light induced luminescence centers in porous SiC prepared from nano-crystalline SiC grown on Si by hot filament chemical vapor deposition

Intense photoluminescence (PL) was observed at room temperature from porous SiC samples prepared in electrochemical anodization from nano-crystalline SiC thin films grown on Si (100) substrates by hot filament chemical vapor deposition. Raman scattering spectroscopy and high-resolution transmission electron microscopy confirmed the nano-crystalline structure of the host films. For the porous samples formed under weaker anodization conditions, it was found that prolonged irradiation with ultraviolet (UV) light from a He–Cd laser (325 nm, 10 mW) can induce an enhanced new PL band and change the peak energy from 1.9 eV to 2.1 eV at room temperature. A defect model is suggested to explain the UV light induced PL change in porous SiC.