EFFECTS OF SOURCE DOPING PROFILE ON DEVICE CHARACTERISTICS OF LATERAL AND VERTICAL TUNNEL FIELD-EFFECT TRANSISTORS

The source doping engineering, the low bandgap material and the vertical tunneling structure have recently been considered as most effective techniques to resolve the on-current issue in tunnel field-effect transistors (TFETs). In this paper, the effects of source doping profile, including the concentration and gradient, on the device characteristics are adequately elucidated in lateral and vertical TFETs using low bandgap germanium to allow a comprehensive comparison between the two major TFET architectures for the first time. Similar dependences of the on-current on the source concentration are observed in lateral and vertical TFETs, except that the on-current of vertical TFETs is always greater than that of lateral TFETs approximately one order of magnitude. With different contributions of the lateral and vertical tunneling components in the subthreshold region, the subthreshold swing of vertical TFETs first decreases at small concentrations, then increases at medium values, and finally decreases again at high concentrations, whereas that of lateral counterparts always decreases exponentially with increase in the source concentration. The on-current of lateral TFETs is significantly decreased, while that of vertical TFETs is almost invariable with increasing the source doping gradient. With competitive advantages of the vertical TFET architecture in on-current, subthreshold swing and device fabrication, vertical TFETs using low bandgap semiconductors are promising for use in low power applications

Interaction between triphenylphosphine or 1,2-bis(diphenylphosphino)ethane with some complexes K[PtCl3(olefin)] (olefin: methyleugenol, safrole, isopropyl eugenoxyacetate)

Novel study on the interaction between K[PtCl3(olefin)] (olefin: methyleugenol, safrole and isopropyl eugenoxyacetate) with TPP and DPPE shows that TPP and DPPE readily replace the olefins to form complexes [PtCl2(TPP)2] (P4), [PtCl2(DPPE)] (P5) and [Pt(DPPE)2]Cl2 (P6). P4 possesses trans configuration when the molar ratio of the mono olefin and TPP of 1:1. When the ratio is 1:2, P4 is a mixture of trans and cis isomers of which trans one is prevailing. The cis isomer trends to convert to trans one in chloroform solvent. P5 and P6 were formed when the molar ratio of mono isopropyl eugenoxyacetate and DPPE of 1:1 and 1:2, respectively. The structures of P4÷P6 were elucidated by Pt analysis, ESI-MS, IR and 1H NMR spectra studies. Keywords. Pt(II) complexes, olefins, phosphine derivatives

Neutron transition strengths of 21+2^+_1 states in the neutron rich Oxygen isotopes determined from inelastic proton scattering

A coupled-channel analysis of the $^{18,20,22}$O$(p,p')$ data has been performed to determine the neutron transition strengths of 2$^+_1$ states in Oxygen targets, using the microscopic optical potential and inelastic form factor calculated in the folding model. A complex density- and \emph{isospin} dependent version of the CDM3Y6 interaction was constructed, based on the Brueckner-Hatree-Fock calculation of nuclear matter, for the folding model input. Given an accurate isovector density dependence of the CDM3Y6 interaction, the isoscalar ($\delta_0$) and isovector ($\delta_1$) deformation lengths of 2$^+_1$ states in $^{18,20,22}$O have been extracted from the folding model analysis of the $(p,p')$ data. A specific $N$-dependence of $\delta_0$ and $\delta_1$ has been established which can be linked to the neutron shell closure occurring at $N$ approaching 16. The strongest isovector deformation was found for 2$^+_1$ state in $^{20}$O, with $\delta_1$ about 2.5 times larger than $\delta_0$, which indicates a strong core polarization by the valence neutrons in $^{20}$O. The ratios of the neutron/proton transition matrix elements ($M_n/M_p$) determined for 2$^+_1$ states in $^{18,20}$O have been compared to those deduced from the mirror symmetry, using the measured $B(E2)$ values of 2$^+_1$ states in the proton rich $^{18}$Ne and $^{20}$Mg nuclei, to discuss the isospin impurity in the $2^+_1$ excitation of the $A=18,T=1$ and $A=20,T=2$ isobars.Comment: Version accepted for publication in Physical Review

Développement des capteurs sans fil basés sur les tags RFID uhf passifs pour la détection de la qualité des aliments

Le but de cette thèse est de développer des capteurs sur la base des tags RFID, des technologies et matériaux disponibles au Vietnam afin de contribuer à résoudre la problématique du contrôle de la qualité des produits alimentaires. En effet la technologie RFID s est affirmée en importance pour ses applications dans de nombreux domaines. Dans ce contexte, l identification des produits alimentaires expirés, sans les endommager, est une orientation de recherche très prometteuse. Un tag RFID UHF passif peut aussi être composé de plusieurs puces et plusieurs antennes, chaque couple puce/antenne conçu pour travailler sur un intervalle déterminé de valeur de permittivité. Donc, à partir de l ensemble des permittivités définies pour chaque couple puce/antenne et les signaux réfléchis vers le lecteur, nous pourrons mesurer la permittivité de l objet tracé. Ainsi la connaissance de la permittivité des aliments et la conception spécifique de l antenne, nous développerons un tag capteur de type "multi puce/antenne" qui sera utilisé comme un capteur sans fil pour la détection de la qualité des alimentsIn recent years, RFID technology has established itself in importance, particularly for applications in the civil sector. In this context, identification of expired products without damage is a very promising direction of research. However, the price of these sensors is still too high especially compared to living in Vietnam. A passive UHF RFID tag chip can include many antennae and many chips on a same substrate in which each pair of chip/antenna is designed to be activated on a determined interval value of permittivity. So from designed permittivities for each pair of chip/antenna and the reflected signals to the reader, we can define the value of permittivity of the object that is labelled with RFID tag. From the characterization of food permittivity and the background of antenna design, we developped a sensor tag "multi chip/antenna" to be used as a wireless sensor for the detection of food quality. The aim of this thesis intends to develop a new family of wireless sensors based on RFID technology and available technology of fabrication in Vietnam to solve this problem.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Design and performance analysis of a mechanically coupled spring compliant to out-of-plane oscillation

In this paper, a spring system symmetrically arranged around a circular plate compliant to out-of-plane oscillation is proposed. The spring system consists of single serpentine springs mutually coupled in a plane. Three theoretical mechanical models for evaluating the stiffness of the spring system are built, which are based on the flexural beam, Sigitta, and serpentine spring theories and equivalent mechanical spring structure models. The theoretically calculated results are in good agreement with numerical solutions using the finite element method, with errors less than 10% in the appropriate dimension ranges of the spring. Compared to similar spring structures without mechanical coupling, the proposed mechanically coupled spring shows advantage in suppressing the mode coupling

Roles of Gate-Oxide Thickness Reduction in Scaling Bulk and Thin-Body Tunnel Field-Effect Transistors

Tunnel field-effect transistor (TFET) has recently been considered as a promising candidate for low-power integrated circuits. In this paper, we present an adequate examination on the roles of gate-oxide thickness reduction in scaling bulk and thin-body TFETs. It is shown that the short-channel performance of TFETs has to be characterized by both the off-current and the subthreshold swing because their physical origins are completely different. The reduction of gate-oxide thickness plays an important role in maintaining low subthreshold swing whereas it shows a less role in suppressing off-state leakage in short-channel TFETs with bulk and thin-body structures. When scaling the gate-oxide thickness, the short-channel effect is suppressed more effectively in thin-body TFETs than in bulk devices. Clearly understanding the roles of scaling gate-oxide thickness is necessary in designing advanced scaled TFET devices

Influences of the mole ratio SnO2/NaOH on the growth of SnO2 nanorods

SnO2 nanorods have been successfully prepared by hydrothermal method at low temperature. The mole ratio of SnO2/ NaOH plays important role in the morphology and diameter of SnO2 nanorod. Besides, the possible growth mechanisms of SnO2 nanorods are also discussed. Structural properties and surface morphologies of the SnO2 nanorods were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results show that diameters of the nanorods are around 100 nm to 300 nm with lengths of several micrometers. With the success of preparing SnO2 nanorods, which will improve in the research and preparation of gas sensor based on SnO2 materials. Keywords: SnO2, nanorods, hydrothermal method

N-terminal pro-B-type Natriuretic peptide levels and left atrial appendage thrombosis in patients with persistent atrial fibrillation

Introduction: In hospitalized patients, atrial fibrillation is the most common arrhythmia, and leading cause of cardio-embolic stroke. Objective: To evaluate the association between N-terminal b-type natriuretic peptide pro (NT-proBNP) and left atrial appendage thrombus in persistent atrial fibrillation patients. Methods: A cross-sectional study, enrolled 139 patients with persistent non-valvular atrial fibrillation. Transthoracic and trans-esophageal echocardiographs were performed in all patients. Results: Mean age was 70.5 ± 10.6 years, 80.6% male. In patients with LAAT, NT-proBNP was positively correlated with left ventricular end diastolic diameter (LVEDD) (r=0.345), left ventricular end-systolic diameter (LVEDS) (r= 0.449), E/e' (r=0.445), and left atrial spontaneous echo contrast (LA SEC) (r=0.478), and negatively correlated with left ventricular ejection fraction (LVEF) (r=-0.473), left atrial strain (r= -0.301), strain rate (r= -0.283), and e'(r= -0.458). In patients without LAAT, NT-proBNP was positively correlated with LVEDD (r= 0.333), LVESD (r= 0.358), E (r= 0.318), E/e' (r= 0.411), left atrial volume index (LAVI) (r= 0.421), and negatively correlated with LVEF (r= -0.307). Plasma NT-proBNP (> 1279 pg/mL) could be used to predict LAAT (AUC= 0.639; Se= 67.7%, Sp= 60.2%). In patients with ejection fraction > 50%, the cutoff value of NT-proBNP to predict LAAT was 1325 pg/mL (AUC= 0.572; Se= 57.9%, Sp= 78.3%). Multiple logistic regression analysis showed that prior stroke, E/e' index, and NT-proBNP correlated with LAAT (r= 0.887; p< 0.001; r= -0.092, p= 0.035 and 0.022; p= 0.004, respectively). Conclusion: Plasma NT-proBNP levels and E/e' index are associated with LAAT in patients with persistent atrial fibrillation

Investigation of Sodium Manganese Oxide Nanowires Synthesized by Hydrothermal Method for Alkaline Ion Battery

Sodium Manganese Oxide (NaxMnO2) has attracted much attention as cathode materials for alkaline ion battery due to the ability of fast charge and discharge ion Na+, in particular in nanoscale. We report on the synthesis of NaxMnO2 nanowires via hydrothermal synthesis route from Mn2O3 and NaOH solution. The morphological observation indicates that the obtained Na0.44MnO2 nanowires with diameters of about 20-30 nm, length up to several micrometers were formed by this process. The electrochemical properties of fabricated materials were investigated by means of cyclic voltammetry technique and show that Sodium Manganese Oxide (NaxMnO2) is a promising material in the field of research and fabrication alkaline ion battery