Self-excited oscillation processes in porous-silicon-based structures

It was found that the dynamic current-voltage (I-U) characteristics of the n-type porous-silicon-based structures upon prolonged room-temperature stor age exhibit negative differential conductivity. Exposure of the samples to a vapor of polar molecules led to the development of self-excited oscillati ons both during the I-U measurements and in the course of reverse current r elaxation in the structure studied. The observed effects are explained by t he formation of deep surface energy levels and their charging by an electri c current passing upon exposure to the atmosphere containing polar molecule s. (C) 2000 MAIK "Nauka/Interperiodica".