Influence of high-temperature AIN buffer thickness on the properties of GaN grown on Si(111)

The influences of AlN buffer thickness on the optical and the crystalline properties of metalorganic chemical vapor deposition wurtzite GaN layers on Si(I 11) substrate have been investigated. High-resolution X-ray diffraction and photoluminescence measurement reveal that the thickness of AlN buffer exerts a strong influence on the distribution of dislocation and stress in GaN epilayer. The evidence is further reinforced by atomic force microscopic observation of AlN nucleation process. The optimum thickness of AlN buffer to effectively suppress Si diffusion has been determined by secondary-ion mass spectroscopy to be in the range of 13-20 nm. In addition, it is found that appropriate Si diffusion in AlN buffer helps to compensate the tensile strain in GaN, which subsequently improves the optical quality of GaN on Si(I 1, 1), and reduces the cracks over the GaN surface. (C) 2003 Elsevier B.V. All rights reserved.

Hydrogen sensors based on Pt-AlGN/AIN/GaN Schottky diode - art. no. 68291R

Pt/AlGaN/AlN/GaN Schottky diodes have been fabricated and characterized for H-2 sensing. Platinum (Pt) with a thickness of 20nm was evaporated on the sample to form the Schottky contact. The ohmic contact, formed by evaporated Ti/Al/Ni/Au metals, was subsequently annealed by a rapid thermal treatment at 860 degrees C for 30 s in N-2 ambience. Both the forward and reverse current of the device increased greatly when exposed to H-2 gas. The sensor's responses under different hydrogen concentrations from 500ppm to 10% H-2 in N-2 at 300K were investigated. A shift of 0.45V at 297K is obtained at a fixed forward current for switching from N-2 to 10% H-2 in N-2. Time response of the sensor at a fixed bias of 0.5 V was also measured. The turn-on response of the device was rapid, while the recovery of the sensor at N-2 atmosphere was rather slow. But it recovered quickly when the device was exposed to the air. The decrease in the barrier height of the diode was calculated to be about 160meV upon introduction of 10% H-2 into the ambient. The sensitivity of the sensor is also calculated. Some thermodynamics analyses have been done according to the Langmuir isotherm equation.

Room temperature mobility above 2100 cm2/Vs in Al0.3Ga0.7N/AIN/GaN heterostructures grown on sapphire substrates by MOCVD

Al0.3Ga0.7N/AlN/GaN HEMT structures with significantly high mobility have been grown by metalorganic chemical vapor deposition (MOCVD) on sapphire substrates. At room temperature (RT) a Hall mobility of 2104 cm(2)/Vs and a two-dimensional electron gas (2DEG) density of 1.1x10(13) cm(-2) are achieved, corresponding to a sheet resistance of 277.8 Omega/sq. The elimination of V-shaped defects were observed on Al0.3Ga0.7N/AlN/GaN HEMT structures and correlated with the increase of 2DEG mobility. (c) 2006 WILEY-VCH Verlag GmbH & Co KGaA, Weinheim.

Molecular beam epitaxial growth of GaN on 3c-SiC/Si(111) substrates using a thick AIN buffer layer

Hexagonal GaN films (similar to 3 mu m) were grown on 3c-SiC/Si(111) and carbonized Si(111) substrates using a thick AlN buffer Cracks are observed on the surface of the GaN film grown on the carbonized Si(111), while no cracks are visible on the 3c-SiC/Si(111). XRD exhibits polycrystalline nature of the GaN film grown on the carbonized Si(111) due to poorer crystalline quality of this substrate. Raman spectra reveal that all GaN layers are under tensile stress, and the GaN layer grown on 3c-SiC/Si(111) shows a very low stress value of sigma(xx) = 0.65 Gpa. In low-temperature Photoluminescence spectra the remarkable donor-acceptor-pair recombination and yellow band can be attributed to the incorporation of Si impurities from the decomposition of SiC.

AIN Monolithic Microchannel Cooled Heatsink for High Power Laser Diode Array

A novel AIN monolithic microchannel cooled heatsink for high power laser diode array is introduced.The high power stack laser diode array with an AIN monolithic microchannel heatsink is fabricated and tested.The thermal impedance of a 10 stack laser diode array is 0.121℃/W.The pitch between two adjacent bars is 1.17mm.The power level of 611W is achieved under the 20% duty factor condition at an emission wavelength around 808nm.

Lanxide技术合成含烧结助剂的复合AIN粉体

高纯度的氮气中，以Al-Mg-Y合金为母合金，利用Lanxide技术合成了含烧结助剂 Y_2O_3的复合AIN粉体．通过扫描电镜、X射线衍射、粒径分析及化学成分分析等检测手段对氮化产物进行表征．实验结果表明，合金氮化反应完全，氮化产物疏松易于粉化．粉化后获得的复合AIN粉体具有纯度高，氧杂质含量低，粒度细小等优点。

具有AIN膜的半导体激光器的实验研究

于2010-11-23批量导入

Les Tron?ons de la po?sie, V. Hugo, J-L. Parant, V. Novarina, E. Savitzkaya

Sibona, Bruno, 'Les Tron?ons de la po?sie, V. Hugo, J-L. Parant, V. Novarina, E. Savitzkaya', In: Ecrire l'Animal aujourd'hui, (ed.) Lucile Desblache, (Presses Universitaires Blaise Pascal/CRLMC), pp.163-175, 2006

Les Tritons de Th?ophile

Sibona, Bruno, 'Les Tritons de Th?ophile', L'Esprit cr?ateur - Literature and Ecology (2006) 46(2) pp.17-32

Les manuscrits latins de la Chirurgia d'Albucasis et la lexicographie du latin m?di?val

Trotter, David, 'Les manuscrits latins de la Chirurgia d'Albucasis et la lexicographie du latin m?di?val', Archivum Latinitatis Medii Aevi (Bulletin Du Cange) (2001) 59(1) pp.181-202 RAE2008

Les tribulations parisiennes de l’officier écrivain : l’oeuvre autobiographique de Yasmina Khadra et son accueil en France

This article describes Yasmina Khadra’s autobiographical work composed of two books: "L’écrivain" and "L’imposture des mots" and its reception in France. The main purpose of this study was to establish the literary genre of these books, which implies determining whether Khandra’s work represents an autobiography or an autofiction with reference to P. Lejeune’s and V. Colonna’s theoretical studies. The dividing line between two genres in Khandra’s works refl ects his inner split between being either a solder or a writer. The presentation will also help to understand the controversy resulting from Khandra’s participation in Algerian civil war. Moreover the analysis is related to modern Algerian history.

Les anglicismes dans le dicours électronique médié

Although French is a Romance language descendant ffrom the Latin, there is of course some influence of other languages on it. English is perhaps the most important source of loan-words for the present French language. Our article is focused on new forms of written communication, mainly computer-mediated communication (CMC). The main aim of this article is to analyze the loan-words, especially the anglicisms that are used by chatters in various French chats. After examining the motivations of loan, the article studies the frequency of anglicisms in three chats and observes their grammatical adaptation in the context of CMC. A huge richness of anglicisms is illustrated by concrete examples taken from our corpus.

Les difficultés perceptives en formation de somato-psychopédagogue

Dissertação de Mestrado apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Psicopedagogia Perceptiva.

Dix-huit ans chez les sauvages : voyages et missions de Mgr Henry Faraud, áevãeque d'Anemour, vicaire apostolique de Mackensie dans l'extrãeme nord de l'Amerique britannique : d'apráes les documents de Mgr l'evãque d'Anemour / par Fernand-Michel.

http://www.archive.org/details/dixhuitanschezle00fararich