X-RAY PHOTOELECTRON-SPECTROSCOPY OF LUMINESCENT POROUS SILICON

X-ray photoelectron spectroscopy has been performed in photoluminescen t porous Si layers after different treatments, namely, anodisation onl y in a HF-ethanol solution, rinsing in deionised water ethanol immersi on, and exposure to ambient conditions. The spectra recorded just afte r formation in the HF solution are the most representative of real por ous Si layer structures. However, the pretreatment in water, exposure to ambient conditions for a long period and immersion in ethanol degra des the porous Si layer surface to a greater or lesser extent. The gro wth of different oxide phases and the amorphisation of the structures after the pretreatments are also discussed.