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Author

Yves Caudano

Other affiliations: Alcatel-Lucent
Bio: Yves Caudano is an academic researcher from Université de Namur. The author has contributed to research in topics: Infrared spectroscopy & Sum frequency generation spectroscopy. The author has an hindex of 16, co-authored 49 publications receiving 1103 citations. Previous affiliations of Yves Caudano include Alcatel-Lucent.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the fundamental mechanism underlying hydrogen-induced exfoliation of silicon, using a combination of spectroscopic and microscopic techniques, was investigated, and the evolution of the internal defect structure as a function of implanted hydrogen concentration and annealing temperature was studied.
Abstract: We have investigated the fundamental mechanism underlying the hydrogen-induced exfoliation of silicon, using a combination of spectroscopic and microscopic techniques. We have studied the evolution of the internal defect structure as a function of implanted hydrogen concentration and annealing temperature and found that the mechanism consists of a number of essential components in which hydrogen plays a key role. Specifically, we show that the chemical action of hydrogen leads to the formation of (100) and (111) internal surfaces above 400 °C via agglomeration of the initial defect structure. In addition, molecular hydrogen is evolved between 200 and 400 °C and subsequently traps in the microvoids bounded by the internal surfaces, resulting in the build-up of internal pressure. This, in turn, leads to the observed “blistering” of unconstrained silicon samples, or complete layer transfer for silicon wafers joined to a supporting (handle) wafer which acts as a mechanical “stiffener.”

319 citations

Journal ArticleDOI
TL;DR: In this paper, the pivotal role that vacancy structures play in driving the H-induced exfoliation of Si has been discussed and the role of coimplantation of He is also discussed.
Abstract: In this paper, we review the pivotal role that defects (in particular vacancy structures) play in driving the H-induced exfoliation of Si. We highlight the central role that infrared spectroscopy has played in delineating the microscopic details of the exfoliation process. We show that when the results of such spectroscopic studies are combined with those obtained using a variety of other experimental probes as well as ab initio quantum chemical cluster calculations, an unambiguous mechanistic picture emerges. Specifically we find that H-terminated vacancy structures drive the formation of internal surfaces into cracks where H2 is then evolved, resulting in the build-up of sufficient internal pressure to cause lift-off of the overlying Si. The role of coimplantation of He is also discussed.

70 citations

Journal ArticleDOI
24 Jul 2004-Langmuir
TL;DR: Two-color sum-frequency generation spectroscopy is used to probe the molecular and electronic properties of an adsorbed layer of the green fluorescent protein mutant 2 on a platinum (111) substrate and reveals two electronic transitions corresponding to the absorption and fluorescence energy levels which are related to two different GFPmut2 conformations: the B and I forms, respectively.
Abstract: Two-color sum-frequency generation spectroscopy (2C-SFG) is used to probe the molecular and electronic properties of an adsorbed layer of the green fluorescent protein mutant 2 (GFPmut2) on a platinum (111) substrate. First, the spectroscopic measurements, performed under different polarization combinations, and atomic force microscopy (AFM) show that the GFPmut2 proteins form a fairly ordered monolayer on the platinum surface. Next, the nonlinear spectroscopic data provide evidence of particular coupling phenomena between the GFPmut2 vibrational and electronic properties. This is revealed by the occurrence of two doubly resonant sum-frequency generation processes for molecules having both their Raman and infrared transition moments in a direction perpendicular to the sample plane. Finally, our 2C-SFG analysis reveals two electronic transitions corresponding to the absorption and fluorescence energy levels which are related to two different GFPmut2 conformations: the B (anionic) and I forms, respectively. Their observation and wavelength positions attest the keeping of the GFPmut2 electronic properties upon adsorption on the metallic surface.

63 citations

Journal ArticleDOI
TL;DR: In this article, sum-frequency generation and infrared absorption were used for vibrational spectroscopy of fullerene thin films, and the coupling strength of the vibration to the orbital was evaluated.
Abstract: High-resolution vibrational spectroscopy of fullerene thin films is achieved by sum-frequency generation and infrared absorption. The ${A}_{g}(2)$ mode of ${\mathrm{C}}_{60}$ gains strong infrared activity when the molecule is adsorbed on Ag(111). K doping allows us to demonstrate the process of adsorbate/substrate dynamical charge transfer, by showing, for the first time, the quenching of the mode softening and infrared activity upon tuning of the admolecule electronic properties. These observations enable the quantitative evaluation of the coupling strength of the ${A}_{g}(2)$ vibration to the ${t}_{1u}$ orbital of ${\mathrm{C}}_{60}$.

57 citations

Journal ArticleDOI
TL;DR: In this article, a flash-lamp-pumped Nd:YAG laser using a frequency-doubling nonlinear mirror combined with a two-photon absorber is presented.
Abstract: We report on the performances of the mode locking of a flash-lamp-pumped Nd:YAG laser using a frequency-doubling nonlinear mirror combined with a two-photon absorber. Pulse lengths from 12 to 8 ps are generated. We show that the flat shape of the pulse-train envelope generated by the oscillator is adapted for the synchronous pumping of optical parametric oscillators and we demonstrate the efficient generation of an infrared beam tunable from 3800 to 1100 cm−1 with bandwidth of 2 cm−1 in one single conversion stage in LiNbO3 or AgGaS2. The “all-solid-state” laser system enables surface sum-frequency generation spectroscopy to be performed with high sensitivity and high resolution.

56 citations


Cited by
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Journal Article
TL;DR: This work shows that the spectral distribution and time-dependent decay of light emitted from excitons confined in the quantum dots are controlled by the host photonic crystal, providing a basis for all-solid-state dynamic control of optical quantum systems.
Abstract: Control of spontaneously emitted light lies at the heart of quantum optics. It is essential for diverse applications ranging from miniature lasers and light-emitting diodes, to single-photon sources for quantum information, and to solar energy harvesting. To explore such new quantum optics applications, a suitably tailored dielectric environment is required in which the vacuum fluctuations that control spontaneous emission can be manipulated. Photonic crystals provide such an environment: they strongly modify the vacuum fluctuations, causing the decay of emitted light to be accelerated or slowed down, to reveal unusual statistics, or to be completely inhibited in the ideal case of a photonic bandgap. Here we study spontaneous emission from semiconductor quantum dots embedded in inverse opal photonic crystals. We show that the spectral distribution and time-dependent decay of light emitted from excitons confined in the quantum dots are controlled by the host photonic crystal. Modified emission is observed over large frequency bandwidths of 10%, orders of magnitude larger than reported for resonant optical microcavities. Both inhibited and enhanced decay rates are observed depending on the optical emission frequency, and they are controlled by the crystals’ lattice parameter. Our experimental results provide a basis for all-solid-state dynamic control of optical quantum systems.

1,019 citations

Journal ArticleDOI
TL;DR: In this article, the authors discuss methods of forming silicon-on-insulator (SOI) wafers, their physical properties, and the latest improvements in controlling the structure parameters.
Abstract: Silicon-on-insulator (SOI) wafers are precisely engineered multilayer semiconductor/dielectric structures that provide new functionality for advanced Si devices. After more than three decades of materials research and device studies, SOI wafers have entered into the mainstream of semiconductor electronics. SOI technology offers significant advantages in design, fabrication, and performance of many semiconductor circuits. It also improves prospects for extending Si devices into the nanometer region (<10 nm channel length). In this article, we discuss methods of forming SOI wafers, their physical properties, and the latest improvements in controlling the structure parameters. We also describe devices that take advantage of SOI, and consider their electrical characteristics.

772 citations

Journal ArticleDOI
TL;DR: Wafer bonding allows a new degree of freedom in design and fabrication of material combinations that previously would have been excluded because these material combinations cannot be realized by the conventional approach of epitaxial growth.
Abstract: When mirror-polished, flat, and clean wafers of almost any material are brought into contact at room temperature, they are locally attracted to each other by van der Waals forces and adhere or bond. This phenomenon is referred to as wafer bonding. The most prominent applications of wafer bonding are silicon-on-insulator (SOI) devices, silicon-based sensors and actuators, as well as optical devices. The basics of wafer-bonding technology are described, including microcleanroom approaches, prevention of interface bubbles, bonding of III-V compounds, low-temperature bonding, ultra-high vacuum bonding, thinning methods such as smart-cut procedures, and twist wafer bonding for compliant substrates. Wafer bonding allows a new degree of freedom in design and fabrication of material combinations that previously would have been excluded because these material combinations cannot be realized by the conventional approach of epitaxial growth.

658 citations

Journal ArticleDOI
Hong-fei Wang, Wei Gan, Rong Lu, Yi Rao, Baohua Wu 
TL;DR: In this article, the authors make assessments of the limitations, issues and techniques as well as methodologies in quantitative orientational and spectral analysis with sum frequency generation vibrational spectroscopy (SFG-VS).
Abstract: Sum frequency generation vibrational spectroscopy (SFG-VS) has been proven to be a uniquely effective spectroscopic technique in the investigation of molecular structure and conformations, as well as the dynamics of molecular interfaces. However, the ability to apply SFG-VS to complex molecular interfaces has been limited by the ability to abstract quantitative information from SFG-VS experiments. In this review, we try to make assessments of the limitations, issues and techniques as well as methodologies in quantitative orientational and spectral analysis with SFG-VS. Based on these assessments, we also try to summarize recent developments in methodologies on quantitative orientational and spectral analysis in SFG-VS, and their applications to detailed analysis of SFG-VS data of various vapour/neat liquid interfaces. A rigorous formulation of the polarization null angle (PNA) method is given for accurate determination of the orientational parameter D = ⟨cos θ ⟩/⟨cos3 θ⟩, and comparison between the PNA me...

636 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the most popular IR spectroscopy applications for catalytic applications is presented, starting from the very general basis of the spectroscopic method applied and focusing on the adsorption of chelating compounds on surfaces of mineral oxides.

433 citations