FTIRS study of porous silicon at different oxidation stages

Electroluminiscence (EL) in liquid of porous silicon (PS) has been attribut ed to radiative recombination of electrochemically generated holes from the bulk of the semiconductor and electrons injected into the conduction band of PS by species adsorbed on the surface. An examination of the surface of PS submitted to oxidation by means of Fourier Transform Infrared Spectrosco py indicates that the concentration of Sx-H-x bonds does not significantly vary during the time interval in which EL is recorded, and therefore that t he electrons belonging to the Si-H bonds do not intervene in the generation of EL. (C) 1999 Kluwer Academic Publishers.