Effects of H and O passivation on photoluminescence from anodically oxidized porous Si

Abstract

We have studied the mechanism of photoluminescence (PL) change in porous Si layers (PSLs) by gradually replacing the hydrogen-terminated surface with an oxygen-terminated surface by anodic oxidation at room temperature. The observed PL change did not follow the change in the silicon hydrides detected by transmission Fourier transform spectroscopy (FTIR). FTIR spectra show that the silicon hydrides decreased while the PL increased. The results of this study show that the polysilane species is not solely responsible for efficient luminescence from PSLs. In addition, an enhancement of PL intensities after laser exposure was observed from anodically oxidized PSLs.