Porous silicon microstructure as studied by transmission electron microscopy

Abstract

Cross-sectional and plan-view transmission electron micrograph analysis of the structure of porous silicon reveals that the pore walls are also porous, yielding a large distribution of pore sizes for a given porous silicon sample. This infrastructure appears to be a universal morphological feature of porous silicon, independent of formation conditions and doping. It is proposed that the observed microstructure explains the recently reported results of adsorption isotherm experiments.