Porous silicon multilayers and microcavities, prepared by the pulsed electrochemical etching method, exhibit a variety of reflectivity and photoluminescence spectra. A comparison of the measured results with those calculated based on the transfer matrix method and quantum-box model reveals that the variation of the spectra can be attributed to the change in wavelength position of the stop-band ...

A method for fabrication of three-dimensional (3D) silicon nanostructures based on selective formation of porous silicon using ion beam irradiation of bulk p-type silicon followed by electrochemical etching is shown. It opens a route towards the fabrication of two-dimensional (2D) and 3D silicon-based photonic crystals with high flexibility and industrial compatibility. In this work, we present...

Films of nanocrystalline silicon (nc-Si) were prepared from hydrogenated amorphous silicon (a-Si:H) by using rapid thermal annealing. The formed nc-Si films were subjected to stain etching in hydrofluoric acid solutions in order to passivate surfaces of nc-Si. The optical reflectance spectroscopy revealed the nc-Si formation as well as the high optical quality of the formed films. The Raman sca...

We present a fast, novel method for building porous silicon-based silicon-on-insulator photonic crystals in which a periodic modulation of the refractive index is built by alternating different electrochemical etching currents. The morphology and reflectance spectra of the photonic crystals, prepared by the proposed method, are investigated. The scanning electron micrograph and atomic force mic...

A straightforward metal-particle-induced, highly localized site-specific corrosion-like mechanism was proposed for the formation of aligned silicon-nanowire arrays on silicon in aqueous HF/AgNO3 solution on the basis of convincing experimental results. The etching process features weak dependence on the doping of the silicon wafers and, thus, provides an efficient method to prepare silicon nano...

We propose a dual scale drift-diffusion model for interfacial growth and etching processes. The two scales are: (i) a depletion layer width ∆W surrounding the aggregate and (ii) a drift length l. The interplay between these two antithetical scales yields a variety of distinct morphologies reported in electrochemical deposition of metals, viscous fingering in fluids and in porous silicon formati...