The quenching and recovery of photoluminescence in porous silicon

We have investigated the photoluminescence quenching of porous silicon in different atmospheres and in vacuum. We observe a much faster quenching in vacuum than reported before, which we propose is caused by the difference of structure in p- and n-type porous silicon, or a re-reaction with an electrolyte vapor. We have also investigated the recovery of the photoluminescence. We observe the luminescence intensity to partially recover under the influence of a hydrogen atmosphere, up to 0.1 of its initial value. We propose that this is associated with the stabilization of surface dangling bonds. When the hydrogen atmosphere was changed to the normal atmosphere of air, the photoluminescence intensity started to decrease again due to oxidation. (C) 1996 American Institute of Physics.