Transport mechanisms in porous silicon

The current transport mechanism through porous silicon (PS) films fabricated from 8 to 12 Omega cm p-type silicon (p-Si) substrates has been investigated using current-voltage I(V) measurements on metal/PS/p-Si/metal devices in the temperature range of 77-300 K. The characteristics for all devices show a rectifying behavior with ideality factor very close to unity. A value of 0.7 eV is obtained for the barrier height at the interface between PS and bulk p-Si at room temperature and the barrier height is found to increase with rising temperature. A band model is proposed in order to explain the observed characteristics. (C) 1998 American Institute of Physics.