We present a study of the electrical transport in porous Si layers prepared by anodic etching of two different kinds of (100) p-type Si substrates. It is shown that by choosing a sufficiently thick layer, the problem of injection from the contacts can be eliminated. In this way we measure the intrinsic transport properties. The results suggest that a Poole-Frenkel type of mechanism accounts for the observed electric-field-enhanced conduction.

• Received 16 August 1993

DOI:https://doi.org/10.1103/PhysRevB.49.2981