International audienceWe present a short review of some optical devices based on multilayered porous silicon, which can be easily obtained by varying the formation current during the etching process. These include Bragg reflectors and Fabry–Pérot microcavities, which can be adjusted from the visible to the near infrared. The interface roughness, tragic in the case of multilayers, is studied. It can be drastically reduced when changing the electrolyte viscosity. The high reflectivities obtained in this way are measured by Cavity Ring–Down Spectroscopy. Problems occurring when realising thin layers and an efficient way to adjust precisely the optical thicknesses of the thin layers constituting the multilayered structure are also presented. Finally we present a method of calculation of the emission which takes absorption into account and is able to explain the angular dependence of the luminescence

Amorphization of silicon induced by nanodroplet impact: A molecular dynamics study J. Appl. Phys. 112, 054302 (2012) How to fabricate a semihydrogenated graphene sheet? A promising strategy explored Appl. Phys. Lett. 101, 073114 (2012) Influence of indium cluster on the high and constant background electron density in ternary InxGa1−xN alloys Appl. Phys. Lett. 101, 062102 (2012) A rapid, inexpensive surface treatment for enhanced functionality of polydimethylsiloxane microfluidic channels Biomicrofluidics 6, 036503 (2012) Additional information on J. Appl. Phys.We have studied the influence of the anodization temperature on the formation of porous Si for different current intensities. We have monitored the porosity, growth rate, luminescence, refractive index, and porous Si/bulk Si interface roughness. A strong decrease of the roughness was obtained for low temperature anodization. These results were used to fabricate distributed Bragg reflectors with a remarkable optical quality (R max ϭ99.5%) for low doped p-type silicon.

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A bulk heterojunction of porous silicon and eumelanin, where the columnar pores of porous silicon are filled with eumelanin, is proposed as a new organic-inorganic hybrid material for photovoltaic applications. The addition of eumelanin, whose absorption in the near infrared region is significantly higher than porous silicon, should greatly enhance the light absorption capabilities of the empty porous silicon matrix, which are very low in the low energy side of the visible spectral range (from about 600 nm downwards). The experimental results show that indeed the photocarrier collection efficiency at longer wavelengths in eumelanin-impregnated samples is clearly higher with respect to empty porous silicon matrices.

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We present here a study of Er doping of n+-type porous silicon. The samples were characterized in situ by their electrochemical behavior and ex situ by optical reflectivity and scanning electron microscopy (SEM). A clear correlation between the optical properties and the Er content of the samples is demonstrated. Refractive index dependence on Er content has also been obtained through simulations of reflectivity spectra in the 350–2500 nm range

In this paper we report on the fabrication and characterization of a potentiometric biosensor for the detec- tion of triglycerides. This is constituted by a lipase immobilized on a mesoporous Si matrix. Prototypes, realized on 1 × 1 cm n+ -type silicon wafers, show a very high enzymatic activity. Moreover the properties of these biosensors have been shown to be stable in a several months time interval, clearly showing their advantages with respect to traditional triglycerides detection systems. The Michaelis Menten curve is ob- tained to demonstrate the absence of diffusion problems. Potentiometric measurements are also shown

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