ELECTRICAL CHARACTERIZATION AND MODELING OF WIDE-BAND-GAP POROUS SILICON P-N DIODES

The current through porous silicon p-n junctions is measured as a func tion of bias voltage and temperature. The ideality factor m = 4 value observed under forward bias indicates that channels are present at the unpassivated porous silicon junction surfaces. The generation-recombi nation current stemming from the space-charge regions between the surf ace channels and the bulk silicon regions dominates the measured diode current. From the thermal activation energy of the diode saturation c urrent a value of 2.2 eV is calculated for the band gap of porous sili con, which is in good agreement with the value of 2.0 eV found from th e photo- and electroluminescence spectra emitted by these diodes.