Structured Photoluminescence Spectrum in Laterally Anodized Porous Silicon

Abstract
Visible photoluminescence (PL) has been systematically investigated in laterally anodized porous silicon. The PL peak position was dependent on the distance from the meniscus and shifted towards a shorter wavelength with increasing anodization current density. A PL spectrum exhibiting several structures was observed inside the mirrorlike region on the sample surface, which was interpreted by multiple reflection of the luminescence, not by the quantum size effects. Through the analysis of the PL spectrum, the Si density of the porous layer was roughly estimated to be 37% by means of the effective-medium model.