The diffusion of evaporated Cu in porous material, and the deposition of metal ions in aqueous solution through the porous network, was measured by monitoring the metal concentration depth profile as a function of time by using Auger electron spectroscopy. It was observed that increasing the metal penetration from Cu evaporated samples was related to a quenching of the photoluminescence; in agreement with previous ion quenching results. The diffusion coefficient was deduced from Auger concentration depth profiles and was found to be 7 orders of magnitude lower than that expected for the diffusion of Cu in bulk crystalline Si at room temperature. It was concluded that the deposition of ionic species could not be characterized as being a simple diffusion process. The observed deposition rates depended strongly upon the solute concentration.

D.Andsager, J.M.Hetrick, J.Hilliard, M.H.Nayfeh: Journal of Applied Physics, 1995, 77[9], 4399-402