Growth And Characterization Of Gaalas/gaas And Gainas/inp Structures: The Effect Of A Pulse Metalorganic Flow

GaAlAs/GaAs and GaInAs/InP thick layers, single and multiple quantum wells were grown by atmospheric pressure metalorganic vapor phase epitaxy. Auger electron spectroscopy, wedge transmission electron microscopy, x-ray diffraction, low-temperature photoluminescence, and scanning electron microscopy were used to analyze the crystal quality. These analysis techniques show that layers grown using high vapor pressure metalorganic sources present fluctuations in the ternary alloy composition. We propose that these fluctuations are due to the pulse character of the high vapor pressure metalorganic flow. Bubbling experiments were performed to show the relationship between ternary layer composition fluctuation and the pulse character of the metalorganic flow. High vapor pressure metalorganic source like trimethylgallium presents tens of Angströms growth rate per pulse or bubble whereas a low vapor pressure source like triethylgallium presents few Angströms growth rate per bubble.71117918

Optical and structural investigation of In1-xGaxP free-standing microrods

We present a structural and optical characterization of scepterlike micrometer-sized free-standing structures, composed of a long InGaP rod with a metallic sphere on its top, grown on polycrystalline InP substrates. In contrast to the conventional vapor-liquid-solid growth method, no catalyst was deposited on the substrate. Instead, metallic In liberated from the InP substrate by phosphor evaporation works as the catalyst metal. We performed Raman scattering, photoluminescence spectroscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy measurements on individual structures. The alloy composition measured by microscopic techniques is in agreement with the values obtained by the optical measurements considering that the rod is strain free. The InGaP rods present essentially constant Ga composition within a fluctuation of similar to 10% and efficient optical emission. We also observed a marked increase in the Raman-scattering signal at rod positions near the metallic sphere (the "neck"), which was attributed to a surface-enhanced Raman-scattering effect. Our results demonstrate the possibility of using InGaP rods for optical device applications. (c) 2005 American Institute of Physics.98

Optical And Structural Investigation Of In 1-xga Xp Free-standing Microrods

We present a structural and optical characterization of scepterlike micrometer-sized free-standing structures, composed of a long InGaP rod with a metallic sphere on its top, grown on polycrystalline InP substrates. In contrast to the conventional vapor-liquid-solid growth method, no catalyst was deposited on the substrate. Instead, metallic In liberated from the InP substrate by phosphor evaporation works as the catalyst metal. We performed Raman scattering, photoluminescence spectroscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy measurements on individual structures. The alloy composition measured by microscopic techniques is in agreement with the values obtained by the optical measurements considering that the rod is strain free. The InGaP rods present essentially constant Ga composition within a fluctuation of ∼10% and efficient optical emission. We also observed a marked increase in the Raman-scattering signal at rod positions near the metallic sphere (the "neck"), which was attributed to a surface-enhanced Raman-scattering effect. Our results demonstrate the possibility of using InGaP rods for optical device applications. © 2005 American Institute of Physics.985Chen, C.-C., Yeh, C.-C., (2000) Adv. Mater. (Weinheim, Ger.), 12, p. 738Gupta, R., Xiong, Q., Mahan, G.D., Eklund, P.C., (2003) Nano Lett., 3, p. 1745Chen, C.-C., (2001) J. Am. Chem. Soc., 123, p. 2791Krishnamachari, U., Borgstrom, M., Ohlsson, B.J., Panev, N., Samuelson, L., Seifert, W., Larsson, M.W., Wallenberg, L.R., (2004) Appl. Phys. Lett., 85, p. 2077Ye, D.-X., Karabacak, T., Lim, B.K., Wang, G.-C., Lu, T.-M., (2004) Nanotechnology, 15, p. 817Wang, R.P., Xu, G., Jin, P., (2004) Phys. Rev. B, 69, p. 113303Jie, J., (2004) J. Phys. Chem. B, 108, p. 8249Hu, J., Odom, T.W., Lieber, C.M., (1999) Acc. Chem. Res., 32, p. 435Wagner, R.S., Ellis, W.C., (1964) Appl. Phys. Lett., 4, p. 89Park, W.I., Kim, D.H., Jung, S.-W., Yi, G.-C., (2002) Appl. Phys. Lett., 80, p. 4232Morales, A.M., Lieber, C.M., (1998) Science, 279, p. 208Choi, H.-J., (2003) J. Phys. Chem. B, 107, p. 8721Sacilotti, M., Decobert, J., Sik, H., Post, G., Dumas, C., Viste, P., Patriarche, G., (2004) J. Cryst. Growth, 272, p. 198Gudisken, M., Lieber, Ch., (2000) J. Am. Chem. Soc., 122, p. 8801Gudisken, M., Wang, J., Lieber, Ch., (2001) J. Phys. Chem. B, 105, p. 4062Kato, T., Matsumoto, T., Ishida, T., (1988) Jpn. J. Appl. Phys., Part 1, 27, p. 983Zachau, M., Masselink, W.T., (1992) Appl. Phys. Lett., 60, p. 2098Beserman, R., Hirlimann, C., Balkanski, M., (1976) Solid State Commun., 20, p. 485Abdelouhab, R.M., Braunstein, R., Bärner, K., Rao, M.A., Kroemer, H., (1989) J. Appl. Phys., 66, p. 787Jusserand, B., Slempkes, S., (1984) Solid State Commun., 49, p. 95Xu, H., Aizpurua, J., Käll, M., Apell, P., (2000) Phys. Rev. e, 62, p. 4318Suzuki, M., Niidome, Y., Terasaki, N., Inoue, K., Kuwahara, Y., Yamada, S., (2004) Jpn. J. Appl. Phys., Part 2, 43, p. 554Mahan, G.D., Gupta, R., Xiong, Q., Adu, C.K., Eklund, P.C., (2003) Phys. Rev. B, 68, p. 073402Gordon, B.E., Lee, A.S.W., Thompson, D.A., Robinson, B.J., (2003) Semicond. Sci. Technol., 18, p. 782Sacilotti, M., Masut, R.A., Roth, A.P., (1986) Appl. Phys. Lett., 48, p. 481Deibuk, V.G., (2003) Semiconductors, 37, p. 1151Schuler, O., Wallart, X., Mollot, F., (1999) J. Cryst. Growth, 201, p. 280Wei, S.-H., Ferreira, L.G., Zunger, A., (1990) Phys. Rev. B, 41, p. 8240Vavilova, L.S., (1998) Semiconductors, 32, p. 590Lee, R.T., Fetzer, C.M., Jun, S.W., Chapman, D.C., Shurtleff, J.K., Stringfellow, G.B., Ok, Y.W., Seong, T.Y., (2001) J. Cryst. Growth, 233, p. 490Bernussi, A.A., Carvalho Jr., W., Franco, M.K.K.D., (2001) J. Appl. Phys., 89, p. 489

Vapor-liquid-solid mechanisms: Challenges for nanosized quantum cluster/dot/wire materials

International audienceThe growth mechanism model of a nanoscaled material is a critical step that has to be refined for a better understanding of a nanostructure's dot/wire fabrication. To do so, the growth mechanism will be discussed in this paper and the influence of the size of the metallic nanocluster starting point, referred to later as “size effect,” will be studied. Among many of the so-called size effects, a tremendous decrease of the melting point of the metallic nanocluster changes the physical properties as well as the physical/mechanical interactions inside the growing structure composed of a metallic dot on top of a column. The thermodynamic size effect is related to the bending or curvature of chains of atoms, giving rise to the weakening of bonds between them; this size or curvature effect is described and approached to crystal nanodot/wire growth. We will describe this effect as that of a “cooking machine” when the number of atoms decreases from 1023 at./cm3 for a bulk material to a few tens of them in a 1–2 nm diameter sphere. The decrease of the number of atoms in a metallic cluster from such an enormous quantity is accompanied by a lowering of the melting temperature that extends from 200 up to 1000 K, depending on the metallic material and its size under study. In this respect, the vapor-liquid-solid VLS model, which is the most utilized growth mechanism for quantum nanowires and nanodots, is critically exposed to size or curvature effects CEs. More precisely, interactions in the vicinity of the growth regions should be reexamined. Some results illustrating the growth of micrometer-/nanometer-sized materials are presented in order to corroborate the CE/VLS models utilized by many research groups in today's nanosciences world. Examples of metallic clusters and semiconducting wires will be presented. The results and comments presented in this paper can be seen as a challenge to be overcome. From them, we expect that in a near future an improved model can be exposed to the scientific communit

Cathodoluminescence And Structural Studies Of Nitrided 3d Gallium Structures Grown By Mocvd

Cathodoluminescence (CL) spectrum imaging and grazing incidence X-ray diffraction (GIXRD) are employed to investigate nitride three-dimensional (3D) gallium structures. The metallic precursors are naturally obtained on a large variety of substrates by metal-organic chemical vapor deposition (CVD) with different shape/size controlled by the growth conditions, especially the temperature. These 3D metallic structures are subsequently exposed to a nitridation process in a conventional CVD reactor to form GaN nanocrystals, as confirmed by GIXRD measurements. CL spectroscopy shows visible light emission (2.5-2.8 eV) excited from the GaN in the 3D structures. © 2008 Elsevier B.V.1293176180Levi, B.G., (1996) Phys. Today, 49, p. 18Johnson, N.M., Nurmikko, A.V., DenBaars, S.P., (2000) Phys. Today, 53, p. 31Beaumont, B., Vennéguès, Ph., Gibart, P., (2001) Phys. Stat. Sol. B, 227, p. 1Viste, P., Colombier, I., Donatini, F., Vial, J.C., Baldeck, P., Herino, R., Duc-Maugé, A., Sacilotti, M., (2004) J. Cryst. Growth, 272, p. 466Sacilotti, M., Imhoff, L., Viste, P., Dumas, C., Vial, J.C., Baldeck, P., Colombier, I., Donatini, F., (2004) Jpn. J. Appl. Phys., 43, pp. L698Sacilotti, M., Decobert, J., Sick, H., Post, G., Viste, P., Dumas, C., Patriarche, G., (2004) J. Cryst. Growth, 272, p. 198Nakaema, M.K.K., Godoy, M.P.F., Brasil, M.J.S.P., Iikawa, F., Silva, D., Sacilotti, M., Decobert, J., Patriarche, G., (2005) J. Appl. Phys., 98, p. 053506Chiaramonte, Th., Patriarche, G., Decobert, J., Cardoso, L.P., Sacilotti, M., (2005) Nanotechnology, 16, p. 2790Sacilotti, M., Imhoff, L., Bourgeois, S., Dumas, C., Decobert, J., Baldeck, P., Colombier, I., (2004) J. Cryst. Growth, 261, p. 253Haffouz, S., Hageman, P., Kirilyuk, V., Macht, L., Weyher, J., Larsen, P., (2003) Mater. Sci. Eng. B, 97Chandrasekaran, H., Sunkara, M., MRS proceedings (2001) GaN and Related Alloys, 13, p. 30. , Northrup J.E., Neugebauer J., Chichibu S.F., and Look D.C. (Eds)Duan, X., Lib!e, C., (2000) J. Am. Chem. Soc., 122, p. 188Decobert, J., Patriarche, G., (2002) J. Appl. Phys., 92, p. 5749Romero, M.J., Ramanathan, K., Contreras, M.A., Al-Jassim, M.M., Noufi, R., Sheldon, P., (2003) Appl. Phys. Lett., 83, p. 4770Widmann, F., Simon, J., Pelekanos, N.T., Daudin, B., Feuillet, G., Rouvière, J.L., Fishman, G., (1999) Microelectron J., 30, p. 353Wagner, R., Ellis, W., (1964) Appl. Phys. Lett., 4, p. 89Pinault, M., Pichot, V., Khodja, H., Launois, P., Reynaud, C., L'Hermite, M., (2005) Nano Lett., 5, p. 2394Newman, N., Ross, J., Rubin, M., (1993) Appl. Phys. Lett., 62, p. 1242Le Flohic, M., (2001) Photoniques, 1, p. 2

Cathodoluminescence and structural studies of nitrided 3D gallium structures grown by MOCVD

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Cathodoluminescence (CL) spectrum imaging and grazing incidence X-ray diffraction (GIXRD) are employed to investigate nitride three-dimensional (3D) gallium structures. The metallic precursors are naturally obtained on a large variety of substrates by metal-organic chemical vapor deposition (CVD) with different shape/size controlled by the growth conditions, especially the temperature. These 3D metallic structures are subsequently exposed to a nitridation process in a conventional CVD reactor to form GaN nanocrystals, as confirmed by GIXRD measurements. CL spectroscopy shows visible light emission (2.5-2.8 eV) excited from the GaN in the 3D structures. (C) 2008 Elsevier B.V. All rights reserved.1293176180ANR-Filemon 3-5 FranceConseil Regional de Bourgogne-FranceConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Department of Energy [DE-AC36-99GO10337]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Department of Energy [DE-AC36-99GO10337

X-ray multiple diffraction in the characterization of TiNO and TiO2 thin films grown on Si(001)

TiO2 and TiNxOy thin films grown by low pressure metal-organic chemical vapor deposition (LP-MOCVD) on top of Si(001) substrate were characterized by X-ray multiple diffraction. X-ray reflectivity analysis of TiO2[1 1 0] and TiNO[ 1 0 0] polycrystalline layers allowed to determine the growth rate (-80 angstrom/min) of TiO2 and (-40 angstrom/min) of TiNO films. X-ray multiple diffraction through the Renninger scans, i.e., phi-scans for (0 0 2)Si substrate primary reflection is used as a non-conventional method to obtain the substrate lattice parameter distortion due to the thin film conventional deposition, from where the information on film strain type is obtained. (c) 2006 Elsevier B.V. All rights reserved.25331590159