The electrochemical oxidation of p-type porous silicon prepared under different conditions is investigated. During the oxidation process, bright visible light is emitted from the surface. The time evolution of integrated electroluminescence signals obtained from a silicon photodiode are shown. The signal duration and relative intensity as a function of process parameters during the formation of the porous silicon and during the anodic oxidation are discussed with a view to establish the origin of the luminescence. The experimental results seem to give more evidence for the quantum confinement model. It does, however, not exclude other theories.
Beatrys M. Lacquet,
D. Francois Malan,
"Emission of visible light from porous silicon during anodic oxidation," Optical Engineering 33(9), (1 September 1994). https://doi.org/10.1117/12.175696