SiOx luminescence from light-emitting porous silicon: Support for the quantum confinement/luminescence center model

Abstract

Measurements of hydrogen loss and luminescence as a function of annealing temperature in porous silicon suggest that luminescence is attributable to electron‐hole recombination in SiO_x surface layers with an intensity that is dependent upon the surface hydrogen content. The luminescence is composed of three Gaussian bands similar to those found in amorphous SiO₂. X‐ray photoelectron spectroscopy and scanning electron microscopy show porous silicon has SiO_x on the surface, which is comprised of many particles of about 10 nm size. Collectively, the data strongly support the previously proposed quantum confinement/luminescence center model.