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 storage exhibit negative differential conductivity. Exposure of the samples to a vapor of polar molecules led to the development of self-excited oscillations both during the I-U measurements and in the course of reverse current relaxation in the structure studied. The observed effects are explained by the formation of deep surface energy levels and their charging by an electric current passing upon exposure to the atmosphere containing polar molecules.