Electroluminescence from novel porous silicon p-n junction devices

The electroluminescent properties of various porous silicon pn junction devices have been investigated. Devices were fabricated by constant current anodization method as well as a novel method developed for anodizing heavily doped pn junctions. The constant current anodized devices show electroluminescence only under reverse bias condition. The light emission mechanism in these devices is believed to be similar to the hot electron relaxation mechanism observed in a surface-treated crystalline silicon pn junction diode at breakdown. The pn junctions fabricated by the novel anodization technique show electroluminescence under forward bias condition. The light emission mechanism in these devices is believed to be due to electron-hole injection in the silicon quantum wires.