Abstract

Porous silicon was first discovered by Uhlir in 1956 [1] and 2 years later by Turner [2] during electropolishing experiments but without any further note. Nearly four decades later, porous silicon became very important after the discovery of its possibility to emit light in the visible in 1990 [3, 4]. Besides photoluminescence, also electroluminescence has been investigated intensely [5], especially with respect to optoelectronic applications.