Transport of carriers in metal/porous silicon/c-Si device structures basedon oxidized porous silicon

Current-voltage (I-V) and impedance measurements of oxidized metal/porous s ilicon (PS)/c-Si sandwich structures were performed at various temperatures . The I-V dependence at relatively small bias was found to be determined by the resistance of the PS layer. When the reverse bias is increased the inj ection of carriers commences. A power-law space charge limited current in t he I-V dependence was observed at high forward bias. An exponential energy distribution of localized states with a characteristic energy of 60 meV was calculated from these. The existence of an inversion (n-type) layer with h igh conductivity was established in the p-type c-Si substrate adjacent to t he PS layer. The presence of this inversion layer leads to an increase of t he active device area, capacitance, and reverse current. (C) 2001 American Institute of Physics.