Abstract
A microstructural investigation of porous silicon films, related with a study of carriers transport, is presented. Scanning electron microscopy and conventional transmission electron microscopy with selected area electron diffraction were performed. The films show a double scale porosity: the macroporosity forms an alveolar structure at a micrometric scale and the nanoporosity forms a silicon nanowires network in the alveolar walls and at their surface. Current‐voltage characteristics in the −5 to +5 V range and the temperature dependence of dark current in the 150‐330 K interval at low voltage were measured. The transport properties are explained by means of a simplified quantum confinement model. Two symmetries of the nanowires, cylindrical and square, are investigated and the differences between them are shown to be insignificant. © 1999 The Electrochemical Society. All rights reserved.