OPTICAL INVESTIGATION OF POROUS SILICON MEMBRANES

We present a systematic investigation of the optical properties of two different series of p(+)- and n(+)-porous silicon membranes. Collecti ng first PL on both sides of the membranes, we discuss the samples hom ogeneity. Next, we collect transmission spectra and, on 70 mu m thick samples, resolve small absorption features at about 2.3 eV. This indic ates, for these series of samples, a Stokes-shift of the PL spectra of about 0.6 eV and corresponds with about 30% dispersion in the width o f the corresponding confining systems.