Effects of Oxidation on Electronic States and Photoluminescence Properties of Porous Si

Abstract

Oxidation states of porous Si, oxidized by oxygen excited by electron impact, have been analyzed using synchrotron radiation photoemission spectroscopy (SR-PES), Auger electron spectroscopy (AES), and Fourier transform infrared (FTIR) techniques, and the relationship between the oxidation states and PL properties has been investigated. The energy band gap, peak energy and full width at half-maximum (FWHM) of the PL spectrum are almost unchanged throughout the oxidation process. These results suggest that oxygen bonding itself basically does not affect the transition levels and that its levels are less sensitive to the surface states. The results of these analyses also imply that the skeletal structure of PS crystallites is important in PL mechanisms.