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Philippe M. Fauchet

Other affiliations: Rochester Institute of Technology, AT&T, University of Rochester  ...read more
Bio: Philippe M. Fauchet is an academic researcher from Vanderbilt University. The author has contributed to research in topics: Silicon & Porous silicon. The author has an hindex of 60, co-authored 494 publications receiving 18686 citations. Previous affiliations of Philippe M. Fauchet include Rochester Institute of Technology & AT&T.


Papers
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Journal ArticleDOI
TL;DR: In this article, the effect of the exact shape of the microcrystal and the relationship between the width, shift and asymmetry of the Raman line is calculated and is in good agreement with available experimental data.

1,957 citations

Journal ArticleDOI
TL;DR: The photoluminescence (PL) of silicon quantum dots present in porous silicon can be tuned from the near infrared to the ultraviolet when the surface is passivated with Si-H bonds as discussed by the authors.
Abstract: Depending on the size, the photoluminescence (PL) of silicon quantum dots present in porous silicon can be tuned from the near infrared to the ultraviolet when the surface is passivated with Si-H bonds. After exposure to oxygen, the PL shifts to the red by as much as 1 eV. This shift and the changes in PL intensity and decay time, show that both quantum confinement and surface passivation determine the electronic states of silicon quantum dots. A theoretical model in which new electronic states appear in the band gap of the smaller quantum dots when a Si-O bond is formed, is in good agreement with experiments. This result clarifies the controversy regarding the PL mechanisms in porous silicon.

1,793 citations

Journal ArticleDOI
01 Jan 1996-Nature
TL;DR: In this article, the authors demonstrate the successful integration of silicon-based visible light-emitting devices into a standard bipolar microelectronic circuit by exploiting the thermal and chemical stability of porous silicon.
Abstract: MICROELECTRONIC device integration has progressed to the point where complete 'systems-on-a-chip' have been realized1–3. Now that optoelectronics is becoming increasingly important for information and communication technologies, there is a need to develop optoelectronic devices that can be integrated with standard microelectronics. Conventional semiconductor technology is largely based on crystalline silicon, which (being an indirect bandgap semiconductor) is an inefficient light-emitting material. This has stimulated significant effort towards developing silicon-based optoelectronic components and, of the several strategies explored so far4,5, the use of porous silicon appears the most promising; porous silicon produces high-efficiency, room-temperature, visible photoluminescence6, and its material and optical properties have been studied in detail7,8. But the extreme reactivity and fragility of porous silicon have hitherto prevented its integration with conventional silicon processing technology. We have recently shown9,10 that the thermal and chemical stability of porous silicon can be greatly enhanced — while retaining desirable light-emitting and charge-transport properties — by partial oxidation. Here we take advantage of these improvements in material properties to demonstrate the successful integration of silicon-based visible light-emitting devices into a standard bipolar microelectronic circuit.

780 citations

Journal ArticleDOI
15 Feb 2007-Nature
TL;DR: The development of an ultrathin porous nanocrystalline silicon (pnc-Si) membrane is reported using straightforward silicon fabrication techniques that provide control over average pore sizes from approximately 5 nm to 25’nm, expected to enable a variety of new devices, including membrane-based chromatography systems and both analytical and preparative microfluidic systems that require highly efficient separations.
Abstract: Commercial ultrafiltration and dialysis membranes have broad pore size distributions and are over 1,000 times thicker than the molecules they are designed to separate, leading to poor size cut-off properties, filtrate loss within the membranes, and low transport rates. Nanofabricated membranes have great potential in molecular separation applications by offering more precise structural control, yet transport is also limited by micrometre-scale thicknesses. This limitation can be addressed by a new class of ultrathin nanostructured membranes where the membrane is roughly as thick (approximately 10 nm) as the molecules being separated, but membrane fragility and complex fabrication have prevented the use of ultrathin membranes for molecular separations. Here we report the development of an ultrathin porous nanocrystalline silicon (pnc-Si) membrane using straightforward silicon fabrication techniques that provide control over average pore sizes from approximately 5 nm to 25 nm. Our pnc-Si membranes can retain proteins while permitting the transport of small molecules at rates an order of magnitude faster than existing materials, separate differently sized proteins under physiological conditions, and separate similarly sized molecules carrying different charges. Despite being only 15 nm thick, pnc-Si membranes that are free-standing over 40,000 microm2 can support a full atmosphere of differential pressure without plastic deformation or fracture. By providing efficient, low-loss macromolecule separations, pnc-Si membranes are expected to enable a variety of new devices, including membrane-based chromatography systems and both analytical and preparative microfluidic systems that require highly efficient separations.

731 citations

Journal ArticleDOI
TL;DR: An ultrasensitive two-dimensional photonic crystal microcavity biosensor that can detect a molecule monolayer with a total mass as small as 2.5 fg and measure the redshift corresponding to the binding of glutaraldehyde and bovine serum albumin is demonstrated.
Abstract: We theoretically and experimentally demonstrate an ultrasensitive two-dimensional photonic crystal microcavity biosensor. The device is fabricated on a silicon-on-insulator wafer and operates near its resonance at 1.58 μm. Coating the sensor internal surface with proteins of different sizes produces a different amount of resonance redshift. The present device can detect a molecule monolayer with a total mass as small as 2.5 fg. The device performance is verified by measuring the redshift corresponding to the binding of glutaraldehyde and bovine serum albumin (BSA). The experimental results are in good agreement with theory and with ellipsometric measurements performed on a flat oxidized silicon wafer surface.

487 citations


Cited by
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Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal ArticleDOI
22 Jan 1999-Science
TL;DR: The synthesis of massive arrays of monodispersed carbon nanotubes that are self-oriented on patterned porous silicon and plain silicon substrates is reported and the mechanisms of nanotube growth and self-orientation are elucidated.
Abstract: The synthesis of massive arrays of monodispersed carbon nanotubes that are self-oriented on patterned porous silicon and plain silicon substrates is reported. The approach involves chemical vapor deposition, catalytic particle size control by substrate design, nanotube positioning by patterning, and nanotube self-assembly for orientation. The mechanisms of nanotube growth and self-orientation are elucidated. The well-ordered nanotubes can be used as electron field emission arrays. Scaling up of the synthesis process should be entirely compatible with the existing semiconductor processes, and should allow the development of nanotube devices integrated into silicon technology.

3,093 citations

Proceedings Article
01 Jan 1999
TL;DR: In this paper, the authors describe photonic crystals as the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures, and the interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.
Abstract: The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

2,722 citations

Journal ArticleDOI
TL;DR: This pressurized graphene membrane is the world's thinnest balloon and provides a unique separation barrier between 2 distinct regions that is only one atom thick.
Abstract: We demonstrate that a monolayer graphene membrane is impermeable to standard gases including helium. By applying a pressure difference across the membrane, we measure both the elastic constants and the mass of a single layer of graphene. This pressurized graphene membrane is the world's thinnest balloon and provides a unique separation barrier between 2 distinct regions that is only one atom thick.

2,648 citations

Journal ArticleDOI
TL;DR: A large amount of work world wide has been directed towards obtaining an understanding of the fundamental characteristics of porous Si as mentioned in this paper, and the key importance of crystalline Si nanostructures in determining the behaviour of porous si is highlighted.
Abstract: A large amount of work world-wide has been directed towards obtaining an understanding of the fundamental characteristics of porous Si. Much progress has been made following the demonstration in 1990 that highly porous material could emit very efficient visible photoluminescence at room temperature. Since that time, all features of the structural, optical and electronic properties of the material have been subjected to in-depth scrutiny. It is the purpose of the present review to survey the work which has been carried out and to detail the level of understanding which has been attained. The key importance of crystalline Si nanostructures in determining the behaviour of porous Si is highlighted. The fabrication of solid-state electroluminescent devices is a prominent goal of many studies and the impressive progress in this area is described.

2,371 citations