Porous silicon-based Bragg reflectors and Fabry-Perot interference filters for photonic applications

Abstract

Visible light emission from the porous silicon (PSi) formed by anodic etching of Si in HF solution has raised great interest in view of possible applications of Si based devices in optoelectronics. In particular, multilayers consisting of periodic repetition of two PSi layers whose refractive indices are different can be exploited to design interference filters for controlling the emission wavelength as well as for the spectral narrowing of the wide emission band of Psi. FabryPerot optical microcavities with an active layer of λ/2 or λ sandwiched between two Bragg reflectors, consisting of alternating layers of high and low refractive indices are fabricated on heavily doped p-type silicon. We have investigated the optical properties of these microstructures using reflectivity and photoluminescence measurements at various temperature.

Silicon Porosification: State of the Art

“…40,41,140,374 In this case, the porous silicon generation processes for p-and n-type silicon can be advantageous, since the etching process depends on the concentration of holes in the substrate material. In p-doped silicon the required holes are available as majority carriers, for n-type silicon, holes must be generated via illumination or electrical breakdown.…”

Porous Silicon Characterization and Application: General View

“…A further approach for porous silicon masking material is the possibility to use locally implanted layers (Smith and Collins 1992;Bell et al 1996;Splinter et al 2001;Pagonis et al 2003;Mangaiyarkarasi et al 2006;Frey et al 2007). In this case, advantage is taken from the general fact that the porous silicon generation processes for p-and n-type silicon can be very different because the etching process depends on the concentration of holes in the substrate material.…”