Nanoscale Studies at the Early Stage of Water-Induced Degradation of CH3NH3PbI3 Perovskite Films Used for Photovoltaic Applications.

peer reviewe

Measurement techniques for RF nanoelectronic devices : new equipment to overcome the problems of impedance and scale mismatch

Scaling of electronic device dimensions into the nanoscale regime has been at the basis of the semiconductor industry for several decades. Traditional materials have been pushed to their limits, which means that entirely new materials and new device structures are now required. The development of emerging technologies that include quantum confinement, spin transport, and molecular or correlated materials places increasingly stringent requirements on metrology of these novel devices. Advances in fundamental nanoscience, design of new nanostructures, and progresses in manufacturing of next-generation nanodevices will all depend on our ability to measure accurately and reproducibly the properties and performance characteristics at the nanometer scale over a wide frequency range

Nanoscale capacitors study with an interferometric scanning microwave microscope

Electrical impedance characterization at the nanoscale is a challenge for beyond CMOS investigations and for understanding the electronic properties of nanomaterials. Among the various scanning probe microscopes, Scanning Microwave Microscope (SMM) is of particular interest because it combines nanometric lateral resolution of atomic force microscopes and sub-fF capacitance sensitivity. In particular, using an interferometer, such sensitivity may be further increased, but for reaching aF scale capacitance sensitivity, the probe parasitic capacitance starts to be the limitation. For example, sub-100 nm diameter metallic pads evaporated on 100 nm-thick thermal SiO2 are not distinguished on S11 amplitude signal. In order to overcome this limitation, but also to address clearly the lateral electrical resolution of SMMs, we have fabricated two types of devices: 1- An "on chip calibration kit" composed of patterned metallic pads evaporated on 100 nm-thick SiO2 that provides reference capacitors. 2-"gold nanodots" are nanoscale bottom gold electrodes (from 5 nm to 200 nm) with an ohmic contact to a highly doped silicon subtrate, covered either by self-formed SiO2 during annealing process or by atomic layer deposition of Al2O3 (5 Å and 5 nm). The top electrode is the SMM Pt tip. Nanodot-based Capacitance estimation by finite element analysis with a given load applied on the tip and measured capacitance by SMM (with consideration of the calibration kit) are corroborated. Capacitances as small as 10 aF are measured with a lateral resolution of 30 nm. Finally, we address the role of tip shape, atmosphere (presence of N2), impact of hydrophobic molecules and discuss models when tunnel current is large

Caractérisation quantitative des capacités sous échelle de 10 nm avec un interférométrique scanning-microwave-microscopy

Nous présentons une façon de caractériser quantitativement des capacités sous échelle de 10 nm à l'aide d'un scanning-microwave-microscope modifié avec un interféromètre (iSMM). Des milliers de capacités à l'échelle nanométrique (nanoplots) et un kit de capacités de calibrages sont intégrés et scanné simultanément. Ceci permet la génération d'histogrammes calibré pour les nanoplots en déduisant leurs valeurs de capacités. A cette échelle, les petits ménisques d'eau entourant la pointe d'iSMM devrait être prise en compte. Bien que la sensibilité de la capacité mesurée soit inférieure à l'ordre des attofarads à quelques GHz, une pointe ultrasharp était encore nécessaire d'observer le signal pour les plus petits nanoplots

Putative Protein Biomarkers of Escherichia coli Antibiotic Multiresistance Identified by MALDI Mass Spectrometry

International audienceThe commensal bacteria Escherichia coli causes several intestinal and extra-intestinal diseases, since it has virulence factors that interfere in important cellular processes. These bacteria also have a great capacity to spread the resistance genes, sometimes to phylogenetically distant bacteria, which poses an additional threat to public health worldwide. Here, we aimed to use the analytical potential of MALDI-TOF mass spectrometry (MS) to characterize E. coli isolates and identify proteins associated closely with antibiotic resistance. Thirty strains of extended-spectrum beta-lactamase producing E. coli were sampled from various animals. The phenotypes of antibiotic resistance were determined according to Clinical and Laboratory Standards Institute (CLSI) methods, and they showed that all bacterial isolates were multi-resistant to trimethoprim-sulfamethoxazole, tetracycline, and ampicillin. To identify peptides characteristic of resistance to particular antibiotics, each strain was grown in the presence or absence of the different antibiotics, and then proteins were extracted from the cells. The protein fingerprints of the samples were determined by MALDI-TOF MS in linear mode over a mass range of 2 to 20 kDa. The spectra obtained were compared by using the ClinProTools bioinformatics software, using three machine learning classification algorithms. A putative species biomarker was also detected at a peak m/z of 4528.00

High speed e-beam lithography for gold nanoarray fabrication and use in nanotechnology

E-beam lithography has been used for reliable and versatile fabrication of sub-15 nm single-crystal gold nanoarrays and led to convincing applications in nanotechnology. However, so far this technique was either too slow for centimeter to wafer-scale writing or fast enough with the so-called dot on the fly (DOTF) technique but not optimized for sub-15 nm dots dimension. This prevents use of this technology for some applications and characterization techniques. Here, we show that the DOTF technique can be used without degradation in dots dimension. In addition, we propose two other techniques. The first one is an advanced conventional technique that goes five times faster than the conventional one. The second one relies on sequences defined before writing which enable versatility in e-beam patterns compared to the DOTF technique with same writing speed. By comparing the four different techniques, we evidence the limiting parameters for the writing speed. Wafer-scale fabrication of such arrays with 50 nm pitch allowed XPS analysis of a ferrocenylalkyl thiol self-assembled monolayer coated gold nanoarray

The mechanisms of fat loss during cooking of ‘foie gras’: Proteomic analysis of duck fatty liver

International audienc

The mechanisms of fat loss during cooking of ‘foie gras’: Proteomic analysis of duck fatty liver

International audienc