Porous silicon(PS)was treated in boiling sulphuric acid

and its infrared spectra

photoluminescence(PL)and PL decay in the time range of nanosecond scale have been measured at room temgerature.It was demonstrated that both hydrogen and oxygen atoms could terminate silicon atoms as SI-H and Si-O bonds at the surface and make PS lumlnescence.Moreover

the incorporation of oxygyen atoms into silicon network made the PL intensity increase by two orders of magnitude

and the PL decay faster.he results are interpreted.bymeans ofthree-layer model for PL ofporous silicon.