Papers by Keyword: Germanium

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Authors: Olivier Kim-Hak, Maher Soueidan, Gabriel Ferro, Olivier Dezellus, Ariadne Andreadou, Davy Carole, Efstathios K. Polychroniadis, Jean Claude Viala
Abstract: Twin-free 3C-SiC layers were recently obtained by Vapour-Liquid-Solid mechanism on a a-SiC(0001) substrate using Si-Ge melt. The formation of cubic layers is rather unexpected since growth from the melt is known to promote lateral growth and should thus give homoepitaxial layers. The study of the early stage of such growth, after a simple contact between the melt and the substrate (without adding propane), reveals the precipitation of 3C-SiC elongated islands upon the substrate surface. The chemical interactions inside the Ge-Si-C ternary phase diagram suggest an initial dissolution of the SiC seed in contact with a Ge-rich melt (below 1200°C). When the Si content of the melt subsequently increases upon heating, the dissolved carbon atoms precipitate on the seed surface under the form of 3C-SiC islands. When propane is added, these islands enlarge and coalesce to form a complete 3C layer.
203
Authors: Ahmad Aizan Zulkefle, Maslan Zainon, Zaihasraf Zakaria, Mohd Ariff Mat Hanafiah, Nurul Huda Abdul Razak, Seyed Ahmad Shahahmadi, Md. Akhtaruzzaman, Kamaruzzaman Sopian, Nowshad Amin
Abstract: This paper presents the performance between silicon germanium (SiGe) and crystalline germanium (Ge) solar cells in terms of their simulated open circuit voltage, short circuit current density, fill factor and efficiency. The PC1D solar cell modeling software has been used to simulate and analyze the performance for both solar cells, and the total thickness is limited to 1μm of both SiGe and Ge solar cells. The Si0.1Ge0.9 thickness is varied from 10nm to 100nm to examine the effect of Si0.1Ge0.9 thickness on SiGe solar cell. The result of simulation exhibits the SiGe solar cell give a better performance compared to Ge solar cell. The efficiency of 9.74% (VOC = 0.48V, JSC = 27.86mA/cm2, FF =0.73) is achieved with Si0.1Ge0.9 layer of 0.1μm in thickness whilst 2.73% (VOC = 0.20V, JSC = 27.31mA/cm2, FF =0.50) efficiency is obtained from Ge solar cell.
341
Authors: Bart Onsia, Thierry Conard, Stefan De Gendt, Marc M. Heyns, I. Hoflijk, Paul W. Mertens, Marc Meuris, G. Raskin, Sonja Sioncke, I. Teerlinck, Antoon Theuwis, Jan Van Steenbergen, Chris Vinckier
27
Authors: Laurent Souriau, V. Terzieva, Marc Meuris, Matty Caymax
83
Authors: D. Jishiashvili, R. Dzhanelidze, Z. Shiolashvili, I. Nakhutsrishvili
165
Authors: Aurimas Uleckas, Eugenijus Gaubas, Tomas Ceponis, Kestutis Zilinskas, Rimas Grigonis, Valdas Sirutkaitis, Jan Vanhellemont
Abstract: The characteristics of the band-to-band Auger recombination in Czochralski-grown high resistivity Si and Ge single crystals have been studied using a contactless technique to measure excess carrier decay transients based on infrared absorption by free carriers. The measurements are performed using laser light excitation with wavelengths ranging from 1.2 to 2.5 µm to reduce inhomogeneity effects in the extraction of the Auger recombination parameters. A linear approximation of the initial excess carrier decay lifetime yields an approximate value of the Auger recombination coefficient in Ge γA,Ge ≈ 2×10-31 cm6/s, which is close to that in Si. These characteristics also indicate that the difference in Auger recombination coefficients for the ehh and eeh processes is small. A more detailed fitting procedure applied simultaneously on a series of experimental transients yields a more accurate value of (8±3)×10-31 cm6/s for the Auger recombination coefficient in Ge.
427
Authors: Bernhard Schwartz, Philipp Saring, Tzanimir Arguirov, Michael Oehme, Konrad Kostecki, Erich Kasper, Joerg Schulze, Martin Kittler
Abstract: We analyzed multi quantum well light emitting diodes, consisting of ten alternating GeSn/Ge-layers, were grown by molecular beam epitaxy on Si. The Ge barriers were 10 nm thick and the GeSn wells were grown with 7% Sn and thicknesses between 6 and 12 nm. Despite the high threading dislocation density of 109 to 1010 cm−2 the electroluminescence spectra measured at 300 and 80 K yield a broad and intensive luminescence band. Deconvolution revealed three major lines produced by the GeSn wells that can be interpreted in terms of quantum confinement. Biaxial compressive strain causes a splitting of light and heavy holes in the GeSn wells. We interpret the three lines to represent two direct lines, formed by transitions with the light and heavy hole band, respectively, andan indirect line.
361
Authors: S.Maflin Shaby, A. Vimala Juliet
Abstract: In this paper a surface micromachined MEMS Piezoresistive pressure sensor was designed. A simulation programs were developed to predict the sensitivity and linearity behavior of the piezoresistive pressure sensor. Based on the small and large deflection theory the diaphragm performances were analyzed. Different diaphragm shape, pressure range, placement of resistors and the properties of the resistors were considered during the analysis. The output response of the pressure sensor was also found as a function of temperature and pressure. It was found that silicon germanium gave better sensitivity and less linearity error. The analysis showed that sensitivity and linearity are influenced by diaphragm thickness and length of the sensing resistor used in the diaphragm of the Piezoresistive pressure sensor. It was found that the sensitivity of 5.2mV/V can be achieved for silicon germanium
1024
Authors: A. Almazouzi, E.G. Moya, Jean Bernardini
1047
Authors: Valentin V. Litvinov, Bengt Gunnar Svensson, L.I. Murin, J. Lennart Lindström, Vladimir P. Markevich
Abstract: Intensities of infrared absorption due to asymmetric stretching vibrations of interstitial oxygen atoms in Ge crystals enriched with 16O and 18O isotopes have been compared with oxygen concentrations determined by means of secondary ion mass spectrometry (SIMS). For Ge samples with oxygen content less than 5⋅1017 cm-3 a good correlation has been found between the values of oxygen concentration and values of absorption coefficient in maximum of the absorption band at 855.6 cm-1 with a proportionality coefficient CO = 0.95.1017 сm-2. It is argued that kinetics of oxygen-related thermal double donor formation and oxygen loss upon heat-treatments of Ge crystals at 350 оС cannot be described properly with the application of calibration coefficient CO = 5.1016 cm-2, which is widely used for the determination of oxygen concentration in Ge crystals.
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