PHOTOINDUCED LUMINESCENCE ENHANCEMENT FROM ANODICALLY OXIDIZED POROUSSI

We have investigated the phenomenon of photoluminescence (PL) increase in anodically oxidized porous Si with increasing laser illumination t ime. by transmission Fourier transform infrared spectroscopy (FTIR), P L spectroscopy, and electron paramagnetic resonance. The adsorption of oxygen without hydrogen loss was observed during laser illumination b y FTIR. The PL intensity increased linearly, while the dangling bond ( DB) density decreased with increasing illumination time. By assuming t hat the decrease of DB density has a linear response to the illuminati on time, we identify that the change in DB density is mainly responsib le for the observed PL increase after laser illumination.