ROLE OF HYDROGEN-TERMINATED AND OXYGEN-TERMINATED SURFACES IN THE LUMINESCENCE OF POROUS SILICON

Room-temperature luminescence observed in porous silicon has been attr ibuted either to direct radiative recombination in nanometer-size sili con in the porous silicon network, or to chemical complexes of silicon , hydrogen, and/or oxygen. In this paper, we attempt to correlate resu lts of infrared and photoluminescence spectroscopy of freshly prepared and chemically treated porous silicon layers such that hydrogen or ox ygen related species can be selectively enhanced on the surface of the porous silicon network. Our results indicate that it is difficult to establish a direct correlation between the visible luminescence in por ous silicon and any particular chemical specie(s) such as silicon hydr ide(s), oxide, or siloxene.