Bright Future; December 1993; Scientific American Magazine; by Paul Wallich; 2 Page(s)
Leigh T. Canham knows of 14 different theories that explain why an etched silicon wafer that is 80 percent air glows orange under ultraviolet light. The same material can also emit red, orange, yellow or green under the influence of an electric field. Depending on which explanation turns out to be right, porous silicon could be the next electronic material for a myriad of applications or a quaint dead end.
Today designers who want to build circuits that meld electrons and light--such as optical computers or lasers for fiber-optic communications systems--must use exotic, fragile materials such as gallium arsenide. But if silicon can be made to emit light on a commercial scale, they will have a cheap, durable alternative backed by three decades of manufacturing experience.