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Green H 2 production by solar water splitting relies entirely on the intrinsic properties of the photocatalyst. In this study the impact of these intrinsic properties on the photocatalytic activity of anatase TiO 2 , the quintessential component of state of the art photocatalytic systems was explored at the nanoscale. The exploration involved a holistic microstructural and optical characterization of fully crystallized anatase thin films synthetized by metalorganic chemical vapor deposition. A combination of electron microscopy, spectroscopic ellipsometry, and infrared spectroscopy revealed that when the deposition temperature increased, the morphology evolved from dense to porous and columnar nanostructures. Interestingly, the columns with a complex, tree-like nanostructure photogenerated 18 times more H 2 than the densest sample. This result shows that the beneficial effect of the morphological nano-complexification and crystallographic diversification of the exchange facets on the photocatalytic performance outweighs the detrimental aspects inherent to this evolution, namely the drop of the charge carrier transport and the increase of residual stress. 1. Introduction Research on renewable energy is vital in the current context of global warming and societies that rely on high energy consumption. Hydrogen is a promising source of renewable energy and catalyzed solar water splitting (SWS) is a carbon-free method to produce it. Numerous materials have been tested to catalyze this reaction [1,2]. Among them, TiO 2-because it is non-toxic, chemically stable, abundant and affordable has been widely investigated as a photocatalytic material since Fujishima and Honda's seminal work [3-8]. Despite its high energy band-gap (3.2 eV), crystalline anatase TiO 2 shows attractive opto-electronic properties. It is an indirect semiconductor with a long exciton lifetime [9,10]; it has a conduction band minimum energy level below the redox potential of H+/H 2 (0 V vs. NHE) and a valence band maximum energy level above the redox potential of O 2 /H 2 O (+1.23 V vs. NHE) [11,12].

For a lab-on-chip application, we fabricate a blue bottom emitting strong microcavity organic light emitting diode (OLED), using very smooth and optically thin (25 nm) silver film as anode on a glass substrate. To improve the hole injection in the OLED device, PEDOT-PSS (poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)) has been used, so the silver anode must present not only a very smooth surface but also a strong adherence on the glass and a high wettability to allow a good PEDOT-PSS spin coating deposition. To obtain these physical properties, different 5 nm thick nucleation layers (germanium, chromium, and hydrogenated amorphous carbon) have been used to grow the silver thin films by e-beam deposition. The Ge/Ag bilayer presents all the desired properties: this bilayer, investigated by ellipsometry, optical profilometry, contact angle measurements, and XPS analysis, highlights an ultrasmooth surface correlated with the film growth mode and a high wettability related to its surface chemical composition.

This paper presents an approach to RF MEMS capacitive shunt switch design from K-band up to W-band, based on the scalability of the RF MEMS switch with frequency. The parameters of the switch's equivalent circuit model also follow scaling rules. The measurement results of the fabricated switches show an excellent agreement with simulations which allow to validate the MEMS model in the entire band from 20 GHz up to 94 GHz. This model is going to be used in phase shifter circuit design for antenna array applications. First 60-GHz phase shifter results are also reported here.

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In this paper, a new process is analysed to improve the contact area between a metallic bridge and a signal line of a capacitive switch thanks to a better membrane planarization. Two planarization methods are investigated: thermal process with hard-bake steps and chemical mechanical polishing planarization. Moreover, two different sacrificial layers are used: polyimide (PMGI) and photoresist (AZ1529). For each sacrificial layer and planarization method, the influence of planarity and roughness on down-state capacitance is evaluated. Results show that down-state capacitance is more sensitive to flatness than roughness. Moreover PMGI is the best sacrificial layer to improve down-state capacitance mainly for high resonance frequency switches due to capacitance surface reduction.

We use Raman spectrometry to investigate lattice disorder and strain induced by hydrogen or helium implantation in ͑001͒ and ͑011͒ Si. The phonon peak intensities and the spatial correlation model are used to estimate the amount of damage affecting the phonon coherence length. The redshift due to reduced coherence length is taken into account to fit the model to the experimental spectra. This allows us to correctly estimate a blueshift attributed to a compressive in-plane strain. We observe that the amount of strain increases linearly with the implant dose. For H implants the dependence of strain on crystallographic orientation was discovered. This effect is attributed to the anisotropic morphology of the H-induced extended defects: two-dimensional platelets with preferred orientations versus spherical nanobubbles formed after He implants. Raman results are correlated with the implant damage simulations and compared with the data obtained by other characterization techniques.

An overview of current limitations and challenges with techniques, based either on acoustic or thermal perturbation, providing charge density profiles within insulations, is presented. Even though the resolution could be somewhat improved, technical limitations readily appear, related to the bandwidth of signals to be detected and to the sensitivity. Instead, our purpose here is to exploit near field techniques derived from AFM-Atomic Force Microscopy-. A booming of the availability and versatility of equipments is observed today. A spatial resolution of some tens of nanometers is accessible for charge detection which therefore let's the possibility to investigate selectively regions with specific properties. The measuring conditions and operating mode for both the sensitivity and spatial resolution of the techniques are addressed and examples of application of these techniques to charge detection in insulating materials are presented.