Photoluminescence of chemically vapor deposited Si on silica aerogels

Abstract

We have prepared in situ porous Si by the decomposition of SiH4 at 500 °C on an aerogel substrate. Electron microscopy studies indicate that the as-deposited Si is primarily amorphous while the sample annealed in Ar at 800 °C has various nanometer-sized crystalline Si particles. Visible photoluminescence (PL) can be observed only from the annealed sample and the PL peak red shifts with the annealing temperature from 800° to 1000 °C. The results support the quantum confinement theory as the luminescence mechanism in porous Si.