[10p-N303-1~19] 13.8 Optical properties and light-emitting devices

▲ [10p-N303-19] Photoconduction, Luminescence and Optical Absorption of Porous Nano-Silicon during Chemical Oxidation in aqueous solutions

〇Bernard Gelloz¹, Souki Sakata², Lianhua Jin² (1.Nagoya Univ., 2.Yamanashi Univ.)

Keywords:porous silicon, luminescence, oxidation

The photocurrent, a signature of light transmission through porous silicon (PSi), was used to study the chemical oxidation of p-type PSi in different aqueous solutions. The photocurrent increases as the oxidation progresses since the formed oxide is transparent at the 405 nm light. A model was developed to explain its progress, based on oxidation rates and silicon oxide dissolution rates. The PL increases during oxidation as a result of increased quantum confinement in the PSi structure. Eventually, the efficiency decreases, most likely due to the inevitable decrease in Si emitting centers after the oxidation has consumed a large amount of silicon. Our results shows that the PL efficiency may increase more when the oxide is grown at a slow rate compared to at a high rate.