Porous Structures and Short-Wavelength Photoluminescence of C⁺-Implanted SiO₂ Films

C ions of three different energies were sequentially implanted into SiO₂ films grown by plasma enhanced chemical vapor deposition. Microstructures of the samples were studied with transmission electron microscopy (TEM) and secondary ion mass spectroscopy As revealed by cross-sectional TEM, porous structures had been created in the implanted region during ion implantation. No photoluminescence (PL) was detected from the as-implanted samples. However, intense short-wavelength PL peaking at 360-370nm and ~ 450nm was observed from the annealed samples. The blue light from samples excited by an Xe lamp can be observed by naked eyes at room temperature. The light emission mechanisms are briefly discussed.