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

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 SiOx 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 SiOx 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.