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Showing 1 to 20 of 48 for “"Porous silicon"”.
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Porous Silicon applications in biotechnology
… Nanostructured materials, and among them porous silicon (PS), appear to be good candidates for coupling with biological molecules because of their peculiar characteristics. In the case of porous silicon, the most noticeable are the very large specific area, which allows the loading of …
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Porous silicon surface passivation and optical properties
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1996.
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A nanostructured porous silicon based drug delivery device
… of a novel, electrically-addressable, porous structure-based drug delivery device for the controlled release of therapeutic proteins and peptides, are described in this thesis. <br/><br/>The initial prototype microdevice design incorporates a porous polysilicon (PPSi) structure as a …
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Porous Silicon as Broadband Antireflector for Photovoltaic Application.
<p>In order to minimize the reflection losses, silicon surfaces are textured or antireflection coatings (ARC) are applied on the surface of silicon solar cells. Porous silicon can be achieved by electrochemical anodization of silicon in hydrofluoric acid, but the main disadvantage is that HF is …
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Chemical and biological modification of porous silicon photonic crystals.
Porous silicon (PSi) photonic crystals have aroused research interest as label-free chemical and biological sensing transducers owing to the ease of fabrication, high quality optics and a sensitive optical response to changes in efractive index. A major impediment to using PSi materials as sensors …
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Fabrication and Characterization of a Palladium/Porous Silicon Layer
<p>When porous silicon is plated with a catalytic metal, the two materials can act together as a single entity whose electrical properties are sensitive to its environment – the sensing component of an electrochemical gas sensor. Etching pores into silicon is an electrochemical process; and which …
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Optical properties of size selected nanocrystallites in porous silicon
… thesis concentrated on processing and diagnosing porous silicon nanocrystallites that have novel chemical, structural and photoluminescent properties. FTIR and Auger electron spectroscopy showed that while conventional porous films have incomplete hydrogen passivation and tend to be plagued with …
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Investigating Energetic Porous Silicon as a Solid Propellant Micro-Thruster
Energetic porous silicon has emerged as a novel on-chip energetic material capable of generating thrust that can be harnessed for positioning of millimeter and micron-scale mobile platforms such as microrobots and nano-satellites. Porous silicon becomes reactive when nano-scale pores are infused …
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Porous silicon as a platform for gradient refractive index photonics
Porous silicon (PSi) is a versatile optical material that is formed by electrochemically etching bulk Silicon (Si). The refractive index of PSi is readily modulated by the electrochemical current density, making PSi inherently applicable to gradient refractive index (GRIN) applications. A GRIN …
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Experimental determination of the thermoelectric properties of porous silicon nanowires
"The thermoelectric properties of nanostructured silicon have attracted significant attention in recent work. The objective is to reduce thermal conductivity through the introduction of phonon scattering mechanisms while preserving charge transport. Initial reports on electrolessly etched silicon …
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Quenching of porous silicon photoluminescence by deposition of metal adsorbates
Luminescent porous silicon is formed by anodization of silicon in HF acid in the dark and then under UV illumination. When illuminated with UV, samples exhibit a bright orange photoluminescence with a quantum efficiency of order a few percent. Porous silicon is characterized as a very complex …
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Realization of a 3D gradient index medium in porous silicon
Porous silicon (PSi) and derivative materials like thermally oxidized porous silicon dioxide (PSiO2) are effective medium composites composed of anisotropic columns of solid material (Si or SiO2) and void. During its electrochemical porosification, the material’s refractive index is defined by …
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The fabrication of TiO2 nanostructures on porous silicon for thermoelectric application
… for the growth of TiO2 nanostructures on porous silicon by using Titanium (IV) Butoxide (TBOT) and Hydrochloric acid (HCL) electrolytes. As a substrate, porous silicon samples were fabricated by electrochemical-etching (ECE) process which helps in providing large internal surface that can …
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Effect of Topological Morphology on Optical Filtering Properties of Porous Silicon
Macroporous silicon samples of differing topological porous properties were manufactured by way of electrochemical etching. Different etching parameters (etching current, time, electrolyte concentration) were used on four different (in terms of crystal orientation and resistivity) types of samples …
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Porous Silicon as a Proton Exchange Membrane for Direct Methanol Fuel Cells
… lower voltage generation or ?mixed potential.? Porous Silicon (P-Si) is traditionally used in photovoltaic and photoluminescence applications. Rarely is it used to function as a mechanical filter or membrane. The research deals with investigations into using P-Si as a functioning electrolyte to …
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Porous Silicon Membrane Based Formic Acid Fuel Cells for Micro Power Generation
Most importantly in this work, porous silicon is demonstrated to be a novel proton conducting membrane material for implementation of micro silicon fuel cells. With 5 M formic acid plus 0.5 M sulfuric acid as the fuel, the micro fuel cell based on a p-type porous silicon membrane produces peak …
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Development of enzymatic biofuel cell based on carbon nanotube electrodes on porous silicon
… and characterizing biofuel cell electrodes using porous silicon (p-Si) as the substrate or current collecting platform on which carbon nanotubes (CNTs), both single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MiWNTs), were synthesized directly, followed by enzyme catalyst …
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Effect of controlled oxidation processes on the emission and excitation of porous silicon
The strong luminescence activity of porous silicon prepared by anodization of silicon in HF is a remarkable phenomenon, considering the fact that ordinary crystalline silicon is not at all an efficient light emitter due to the indirect character of its bandgap. In spite of the intense theoretical …
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