Chemical nature of the luminescent centre in fresh and aged porous silicon layers

In this study we have used high resolution parallel electron energy loss spectroscopy (PEELS) and X-ray excited optical luminescence (XEOL) to investigate the chemical nature of the luminescence centre in fresh and aged porous silicon. We find that regardless of the non-stoichiometric oxides which were observed by PEELS in our fresh porous silicon layers, SiSi bonded material is involved in the luminescence process. However, in the case of aged porous silicon both SiSi and SiO bonded material are involved.