Abstract

In 1865, James Clark Maxwell presented his work entitled A Dynamical Theory of the Electromagnetic Field which showed the connection between electricity, magnetism, and light (Maxwell 1865). Maxwell’s equations for handling periodic systems, with the help of Bloch’s theorem, led Yablonovitch to predict the existence of periodic materials in which photonic states are not allowed in the photonic structure (Yablonovitch 1987). The region in which the photonic state is forbidden is the photonic band gap (PBG) where the structures are photonic crystals (PCs). However, because of technological difficulties, the first PC fabrication was only reported 4 years after the first theoretical work and was named Yablonovite (Yablonovitch 1991). To fabricate these structures, different materials and techniques were employed (Lopez 2003; Rodriguez et al. 2005); however, from the universe of materials, crystalline silicon (c-Si) is the most important material because the complementary metal–oxide–semiconductor (CMOS) technology opens up the possibility of engineering optical circuits to manipulate photons in an analogous form to electrons in semiconductors (Yablonovitch 2001). For introducing photonic states within the PBG, a defect structure, microcavity (material with different optical and structural properties), is placed within the periodic structure (Joannopoulos 2008; John 1987; Lopez 2003; Yablonovitch 1987). Its presence produces the confinement of photons with a wavelength proportional to the microcavity optical thickness (John 1987), which are subsequently emitted by spontaneous emission. This can be used to fabricate excellent light-emitting devices (Birner et al. 2001; Pavesi et al. 1996). In particular, in silicon-based PCs, this aim is achieved by inclusion of rare earths (Lopez and Fauchet 2001; Zhou et al. 2000b) or another photoluminescent material, as well as by employing the photoluminescent properties of porous silicon (PS) itself as active material (Kim et al. 2003; Xu et al. 2002). Thus, silicon-based PCs can enable the fabrication of photonic circuits that could be integrated with light-emitting devices using CMOS technology (Gaburro et al. 2000) and thereby enable the fabrication of high-performance computers with high information transfer speed and lossless by heat dissipation.