On the route towards efficient light emitting diodes based on porous silicon

In this paper we present our recent progresses towards efficient light emitting diodes based on porous silicon. We will touch the two following topics: 1) All porous silicon microcavities. Through the formation of a planar optical cavity it is possible to vary the spontaneous emission rate of porous silicon films. We demonstrate this by showing luminescence, and time resolved luminescence measurements performed on all porous silicon periodic and random microcavities. 2) Light emitting diodes based on n-type doped silicon/porous silicon heterojunctions. Exploiting the selectivity of the porous silicon formation process we formed light emitting diodes with superior performance with respect to metal/porous silicon devices. The use of these diodes as gas sensors is also investigated.