VISIBLE-LIGHT EMISSION FROM SIOX FILMS SYNTHESIZED BY LASER-ABLATION

We have developed a method for synthesizing SiOx films with visible li ght emission, applying a laser ablation technique. The films were form ed by depositing laser-ablated silicon particles in oxygen gas diluted with helium gas. Soft X-ray absorption spectroscopy revealed that the composition of the film is controlled by the total pressure of the ga s. Films with particular composition exhibit intense red photoluminesc ence with a peak below 1.5 eV after annealing in argon gas at 1000 deg rees C. In addition to this, most of the films exhibit 2.2-eV photolum inescence after annealing at 500 degrees C. On the basis of these resu lts, the origin of the photoluminescence is discussed.