Porous silicon pn junction light emitting diodes

This paper presents the results of a systematic study of porous silicon light emitting diodes (LEDs). Porous silicon pn junction LEDs, both patterned and unpatterned, were fabricated using the standard anodization method as well as a novel technique developed for the anodization of heavily doped pn junction structures. The current-voltage, photoluminescence and electroluminescence properties of the various porous silicon pn junction LEDs were investigated. The devices fabricated by the standard method show electroluminescence only under reverse bias conditions. The pn junctions fabricated by the novel anodization technique show electroluminescence under forward bias conditions. The light emission mechanism in these devices is believed to be due to electron-hole injection in the silicon nanostructures forming the porous silicon material.