A comparison of cathodoluminescence and photoluminescence of porous silicon and the influence of aging and electron irradiation of these properties

In this paper, Cathodoluminescence and Photoluminescence in porous silicon prepared by different etching times were reported. The Cathodoluminescence emission may originate from the presence of hydrogen atoms in oxide phase, which is reduced by electron beam irradiation, but the Photoluminescence emission may be associated with the defects in dioxide in porous silicon surface, which can be proved by scanning electron microscopy images, Fourier transform infrared spectra and Raman spectra. Under electron beam irradiation, the degradation of Cathodoluminescence intensity from as-prepared sample is attributed to hydrogen-atom desorption from porous silicon surface or destruction of irradiative center on porous silicon surface. During electron-beam radiation, the stabilization of Cathodoluminescence emission of the samples, which are post treated by electron beam exposure for 60 s and then aged for 2 min, is due to the protection of surface oxidized layer generated from electron beam heating. (c) 2007 Elsevier Ltd. All rights reserved.