Monte Carlo Simulations Applied To Alx Gay In1-x-y X Quaternary Alloys (x=as,p,n): A Comparative Study

We develop a different Monte Carlo approach applied to the Ax By C1-x-y D quaternary alloys. Combined with first-principles total-energy calculations, the thermodynamic properties of the (Al,Ga,In) X (X=As, P, or N) systems are obtained and a comparative study is developed in order to understand the roles of As, P, and N atoms as the anion X in the system Alx Gay In1-x-y X. Also, we study the thermodynamics of specific compositions in which AlGaInN, AlGaInP, and AlGaInAs are lattice matched, respectively, to the GaN, GaAs, and InP substrates. We verify that the tendency for phase separation is always towards the formation of an In-rich phase. For arsenides and phosphides this occurs in general for lower temperatures than for their usual growth temperatures. This makes these alloys very stable against phase separation. However, for nitrides the In and/or Al concentrations have to be limited in order to avoid the formation of In-rich clusters and, even for low concentrations of In and/or Al, we observe a tendency of composition fluctuations towards the clustering of the ternary GaInN. We suggest that this latter behavior can explain the formation of the InGaN-like nanoclusters recently observed in the AlGaInN quaternary alloys. © 2005 The American Physical Society.7120Stringfellow, G.B., (1983) J. Appl. Phys., 54, p. 404. , JAPIAU 0021-8979 10.1063/1.331719Olego, D., Chang, T.Y., Silberg, E., Caridi, E.A., Pinczuk, A., (1982) Appl. Phys. Lett., 41, p. 476. , APPLAB 0003-6951 10.1063/1.93537Fujii, T., Nakata, Y., Sigiyama, Y., Hiyiamizu, S., (1986) Jpn. J. Appl. Phys., Part 1, 25, p. 254. , JAPNDE 0021-4922Mowbray, D.J., Kowalski, O.P., Hopkinson, M., Skolnick, M.S., David, J.P.R., (1994) Appl. Phys. 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Theoretical Study Of Strain-induced Ordering In Cubic Inxga 1-xn Epitaxial Layers

Chemical ordering in cubic epitaxial InxGa1-xN layers is investigated by combining first-principles pseudo-potential plane-wave total-energy calculations, a local concentration-dependent cluster-based method, and Monte Carlo simulations. It is found that for the unstrained or fully relaxed layers there are no stable ordered structures, indicating the tendency of the alloy to undergo phase separation, in agreement with previous calculations and experiment. The energetics of the InxGal 1-xN layers pseudomorphycally grown on fully relaxed GaN (001) buffers shows that biaxial strain acts as the driving force for chemical ordering in the alloys. 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Microscopic Description Of The Phase Separation Process In Al Xgayin1-x-yn Quaternary Alloys

Ab initio total energy electronic structure calculations are combined with Monte Carlo simulations to study the thermodynamic properties of Al xGayIn1-x-yN quaternary alloys. We provide a microscopic description of the phase separation process by analyzing the thermodynamic behavior of the different atoms with respect to the temperature and cation contents. We obtained, at growth temperatures, the range of compositions for the stable and unstable phases. The presence of Al in InGaN is proven to "catalyze" the phase separation process for the formation of the In-rich phase. Based on our results, we propose that the ultraviolet emission currently seen in samples containing AlInGaN quaternaries arises from the matrix of a random alloy, in which composition fluctuations toward InGaN- and AlGaN-like alloys formation may be present, and that a coexisting emission in the green-blue region results from the In-rich segregated clusters.707732021-073202-4Lemos, V., Silveira, E., Leite, J.R., Tabata, A., Trentin, R., Scolfaro, L.M.R., Frey, T., Lischka, K., (2000) Phys. Rev. Lett., 84, p. 3666. , and references thereinKung, P., Razegui, M., (2000) Opto-Electron. Rev., 8, p. 201Kneissl, M., Treat, D.W., Teepe, M., Miyashita, N., Johnson, N.M., (2003) Appl. Phys. Lett., 82, p. 2386Adivarahan, V., Chitnis, A., Zhang, J.P., Shatalov, M., Yang, J.W., Simin, G., Khan, M.A., Shur, M.S., (2001) Appl. Phys. Lett., 79, p. 4240Yasan, A., McClintock, R., Mayes, K., Darvish, S.R., Zhang, H., Kung, P., Razeghi, M., Han, J.Y., (2002) Appl. Phys. Lett., 81, p. 2151Nagahama, S., Yanamoto, T., Sano, M., Mukai, T., (2001) Jpn. J. Appl. Phys., Part 2, 40, pp. L778Teles, L.K., Furthmüller, J., Scolfaro, L.M.R., Leite, J.R., Bechstedt, F., (2000) Phys. Rev. B, 62, p. 2475Teles, L.K., Scolfaro, L.M.R., Leite, J.R., Furthmüller, J., Bechstedt, F., (2002) J. Appl. Phys., 92, p. 7109Tamulaitis, G., Kazlauskas, K., Jursenas, S., Zukauskas, A., Khan, M.A., Yang, J.W., Zhang, J., Gaska, R., (2000) Appl. Phys. Lett., 77, p. 2136Hirayama, H., Kinoshita, A., Yamabi, T., Enomoto, Y., Hirata, A., Araki, T., Nanishi, Y., Aoyagi, Y., (2002) Appl. Phys. Lett., 80, p. 207Chen, C.H., Chen, Y.F., Lan, Z.H., Chen, L.C., Chen, K.H., Jiang, H.X., Lin, J.Y., (2004) Appl. Phys. Lett., 84, p. 1480Feng, S.W., Cheng, Y.C., Chung, Y.Y., Yang, C.C., Ma, K.J., Yan, C.C., Hsu, C., Jiang, H.X., (2003) Appl. Phys. Lett., 82, p. 1377Yamaguchi, S., Kariya, M., Nitta, S., Kato, H., Takeuchi, T., Wetzel, C., Amano, H., Akasaki, I., (1998) J. Cryst. Growth, 195, p. 309Takayama, T., Yuri, M., Itoh, K., Harris Jr., J.S., (2001) J. Appl. Phys., 90, p. 2358Matsuoka, T., (1998) MRS Internet J. Nitride Semicond. Res., 3, p. 54Marques, M., Teles, L.K., Ferreira, L.G., Scolfaro, L.M.R., Leite, J.R., unpublishedKresse, G., Furthmüller, J., (1996) Comput. Mater. Sci., 6, p. 15Marques, M., Teles, L.K., Scolfaro, L.M.R., Leite, J.R., Furthmüller, J., Bechstedt, F., (2003) Appl. Phys. Lett., 83, p. 890Ferreira, L.G., Wei, S.-H., Zunger, A., (1991) Int. J. Opt. Sens., 5, p. 34Metropolis, N., Rosenbluth, A.W., Rosenbluth, M.N., Teller, A.H., Teller, E., (1953) J. Chem. Phys., 21, p. 1087Cowley, J.M., (1950) J. Appl. Phys., 21, p. 2

Statistical Model Applied To Ax By C1-x-y D Quaternary Alloys: Bond Lengths And Energy Gaps Of Alx Gay In1-x-y X (x=as, P, Or N) Systems

We extend the generalized quasichemical approach (GQCA) to describe the Ax By C1-x-y D quaternary alloys in the zinc-blende structure. Combining this model with ab initio ultrasoft pseudopotential calculations within density functional theory, the structural and electronic properties of Alx Gay In1-x-y X (X=As, P, or N) quaternary alloys are obtained, taking into account the disorder and composition effects. Results for the bond lengths show that the variation with the compositions is approximately linear and also does not deviate very much from the value of the corresponding binary compounds. The maximum variation observed amounts to 3.6% for the In-N bond length. For the variation of band gap, we obtain a bowing parameter b=0.26 eV for the (Ga0.47 In0.53 As)z (Al0.48 In0.52 As)1-z quaternary alloy lattice matched to InP, in very good agreement with experimental data. In the case of AlGaInN, we compare our results for the band gap to data for the wurtzite phase. We also obtained a good agreement despite all evidences for cluster formation in this alloy. Finally, a bowing parameter of 0.22 eV is obtained for zinc-blende AlGaInN lattice matched with GaN. © 2006 The American Physical Society.7323Li, J., Nam, K.B., Kim, K.H., Lin, J.Y., Jiang, H.X., (2001) Appl. Phys. Lett., 78, p. 61. , APPLAB 0003-6951 10.1063/1.1331087Adivarahan, V., Chitnis, A., Zhang, J.P., Shatalov, M., Yang, J.W., Simin, G., Asif Khan, M., Shur, M.S., (2001) Appl. Phys. Lett., 79, p. 4240. , APPLAB 0003-6951 10.1063/1.1425453Yasan, A., McClintock, R., Mayes, K., Darvish, S.R., Kung, P., Razegui, M., (2002) Appl. Phys. Lett., 81, p. 801. , APPLAB 0003-6951 10.1063/1.1497709Nagahama, S., Yanamoto, T., Sano, M., Mukai, T., (2001) Jpn. J. Appl. Phys., Part 1, 40, p. 788. , JAPNDE 0021-4922 10.1143/JJAP.40.L788Fujii, T., Nakata, Y., Sigiyama, Y., Hiyiamizu, S., (1986) Jpn. J. Appl. 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Magnetic Properties Of Gan Mnx Ga1-x N Digital Heterostructures: First-principles And Monte Carlo Calculations

The energetic and magnetic properties of wurtzite GaN Mnx Ga1-x N digital heterostructures are investigated by first-principles total energy calculations, within the spin density-functional theory, and Monte Carlo simulations. In a wurtzite GaN model sample, periodic in the c axis, we replace a GaN monolayer (a plane) by a plane with composition Mnx Ga1-x N, and study its properties for varying the GaN spacer layer thickness and Mn concentration x. The 100% MnN monolayer possesses an antiferromagnetic (AFM) ground state when, in the periodic sample, it is isolated from the other MnN monolayers by more than four GaN spacer layers. The case of submonolayers (x<1) is studied by Monte Carlo simulations based on an Ising Hamiltonian, whose parameters are obtained from ab initio calculations on five configurations. At 700°C, up to the concentration of 8% Mn, the two-dimensional (2D) alloy is stable. However, above this concentration, there is a strong tendency to the formation of MnN clusters with an AFM ground state defined by ferromagnetic Mn rows coupled antiferromagnetically with other Mn rows. The behavior of the magnetization with the temperature is completely different in these two concentration regimes, with the 2D MnN cluster being very stable, whereas the 2D alloy presents low magnetic transition temperatures. © 2006 The American Physical Society.7322Wolf, S.A., Awschalom, D.D., Buhrman, R.A., Daughton, J.M., Von Molnár, S., Roukes, M.L., Chtchelkanova, A.Y., Treger, D.M., (2001) Science, 294, p. 1488. , SCIEAS. 0036-8075. 10.1126/science.1065389Ohno, H., (1998) Science, 281, p. 951. , SCIEAS 0036-8075 10.1126/science.281.5379.951Ohno, H., Shen, A., Matsukura, F., Oiwa, A., Endo, A., Katsumoto, S., Iye, Y., (1996) Appl. Phys. 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Evidence Of A Two-dimensional To Three-dimensional Transition In Si -doped Gaas Structures

We report on the change of character, from an isolated well to a superlattice, of multiple -doped structures as a function of the doping period ds. This effect is evidenced by the drastic change in the photoluminescence excitation spectra and the deviation on the total electron density extracted from Shubnikovde Haas oscillation measurements as ds decreases. Self-consistent-calculation results performed for these systems are used for comparison. © 1993 The American Physical Society.4816123161231

Ab Initio Studies Of Indium Separated Phases In Algainn Quaternary Alloys

In this work, ab initio total energy electronic structure calculations are combined with Monte Carlo simulations to study microscopically the indium separated phases taking place in Al xGa yIn 1-x-yN quaternary alloys. The presence of aluminum in the InGaN alloy is shown to enhance the phase separation process, compared to the InGaN ternary alloy with the same In compositions. We also observe that even in the stable region of the quaternay alloy there are composition fluctuations towards InGaN- and AlGaN-like alloys formation. From our findings the origin of the emissions which have been observed from AlGaInN quaternary is discussed. © 2005 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.2725082511Nakamura, S., Fasol, G., (1997) The Blue Laser Diode, , Springer, BerlinAmbacher, O., (1998) J. Phys. D: Appl. Phys., 31, p. 2653Pearton, S.J., Zolper, J.C., Shul, R.J., Ren, F., (1999) J. Appl. Phys., 86, p. 1Kung, P., Razegui, M., (2000) Opto-electronics Rev., 8, p. 201Takayama, T., Yuri, M., Itoh, K., Harris Jr., J.S., (2001) J. Appl. Phys., 90, p. 2358Marques, M., Teles, L.K., Ferreira, L.G., Scolfaro, L.M.R., Leite, J.R., Phys. Rev. B, , in pressTeles, L.K., Ferreira, L.G., Leite, J.R., Scolfaro, L.M.R., Kharchenko, A., Husberg, O., As, D.J., Lischka, K., (2003) Appl. Phys. Lett., 82, p. 4274Teles, L.K., Ferreira, L.G., Scolfaro, L.M.R., Leite, J.R., (2004) Phys. Rev. B, 69, p. 245317M. Marques, L. K. Teles, L. G. Ferreira, L. M. R. Scolfaro, and J. R. Leite, unpublishedKresse, G., Furthmüller, J., (1996) Comput. Mat. Sci., 6, p. 15Marques, M., Teles, L.K., Scolfaro, L.M.R., Leite, J.R., Furthmüller, J., Bechstedt, F., (2003) Appl. Phys. Lett., 83, p. 890Metropolis, N., Rosenbluth, A.W., Rosenbluth, M.N., Teller, A.H., Teller, E., (1953) J. Chem. Phys., 21, p. 1087Teles, L.K., Scolfaro, L.M.R., Leite, J.R., Furthmüller, J., Bechstedt, F., (2002) J. Appl. Phys., 92, p. 7109Feng, S.W., Cheng, Y.C., Chung, Y.Y., Yang, C.C., Ma, K.J., Yan, C.C., Hsu, C., Jiang, H.X., (2003) Appl. Phys. Lett., 82, p. 1377Chen, C.H., Chen, Y.F., Lan, Z.H., Chen, L.C., Chen, K.H., Jiang, H.X., Lin, J.Y., (2004) Appl. Phys. Lett., 84, p. 148

Magnetic And Electronic Properties Of Transition Metal Nitride Strained Layers

We present a theoretical study with ab initio techniques on magnetic and electronic properties of 3d transition metal mononitrides. We perform the calculations in the wurtzite (w) and the zincblende (zb) structures, and find the tendency of all zb mononitrides to become half-metallic (HM) under hydrostatic strain. MnN, CrN, and VN become HM with integer magnetic moments of 4, 3 and 2 μB, respectively. CrN shows ferromagnetism (FM) throughout the range of our lattice constant calculations, while VN is FM beyond the lattice constant of 4.65 Å. © 2007 WILEY-VCH Verlag GmbH &amp; Co. KGaA.42269271Picossi, S., Antoniella, F., Continenza, A., MoscaConte, A., (2004) Phys. Rev. B, 70, p. 165205Pearton, S.J., Abernathy, C.R., Ren, F., (2006) Gallium Nitride Processing for Electronics, Sensors and Spintronics, , Spinger-Verlag, LondonRao, B.K., Jena, P., (2002) Phys. Rev. Lett, 89, pp. 185504-185511Das, G.P., Rao, B.K., Jena, P., (2004) Phys. Rev. B, 69, p. 214422Kresse, G., Joubert, D., (1999) Phys. Rev. B, 59, p. 1758Monkhorst, H.J., Pack, J.D., (1974) Phys. Rev. B, 13, p. 5188Wang, Y., Perdew, J.P., (1991) Phys. Rev. B, 43, p. 8911Marques, M., Teles, L.K., Scolfaro, L.M.R., Furthmüller, J., Bechstedt, F., Ferreira, L.G., (2005) Appl. Phys. Lett, 86, p. 16410

Phase Separation, Effects Of Biaxial Strain, And Ordered Phase Formations In Cubic Nitride Alloys

The thermodynamics as well as the energetics and the structural properties of cubic group-III nitrides alloys have been investigated by combining first-principles total energy calculations and cluster expansion methods. In particular results are shown for the ternary In xGa 1-xN and the quaternary Al xGa yIn 1-x-yN alloys. Phase separation is predicted to occur at growth temperatures, for both fully relaxed alloys. A remarkable influence of an external biaxial strain on the phase separation, with the formation of ordered phase structures has been found for the InGaN alloy. These findings are used to clarify the origin of the light emission process in InGaN-based optoelectronic devices. Results are shown for the composition dependence of the lattice constant and of the energy gap in quaternary Al xGa yIn 1-x-yN alloys. © 2004 Elsevier Ltd. All rights reserved.3515357Nakamura, S., (1999) Semic. Sci. Technol., 14, pp. R27Kung, P., Razegui, M., (2000) Opt. Electron. Rev., 8, p. 201Khan, M.A., Kuznia, J.N., Olson, D.T., Schaff, W.J., Burm, J.W., Shur, M., (1995) Appl. Phys. Lett., 65, p. 1121Li, J., Nam, B., Kim, K.H., Lin, J.Y., Jiang, H.X., (2001) Appl. Phys. Lett., 78, p. 61Adivarahan, V., Chitnis, A., Zhang, J.P., Shatalov, M., Yang, J.W., Simin, G., Asif Khan, M., Shur, M.S., (2001) Appl. Phys. Lett., 79, p. 4240Yasan, A., Mcclintock, R., Mayes, K., Darvish, S.R., Kung, P., Razegui, M., (2002) Appl. Phys. Lett., 81, p. 801Nagahama, S., Yanamoto, T., Sano, M., Mukai, T., (2001) Jpn. J. Appl. Phys., 40, pp. L788Madelung, O., (1991) Data in Science and Technology: Semiconductors, , Berlin: SpringerDavydov, V.Y., Klochikhin, A.A., Seisyan, R.P., Emtsev, V.V., Ivanov, S.V., Bechstedt, F., Furthmüller, J., Graul, J., (2002) Phys. Stat. Sol. (b), 229, pp. R1Lemos, V., Silveira, E., Leite, J.R., Tabata, A., Trentin, R., Scolfaro, L.M.R., Frey, T., Lischka, K., (2000) Phys. Rev. Lett., 84, p. 3666Chichibu, S., Azuhata, T., Sota, T., Nakamura, S., (1996) Appl. Phys. Lett., 69, p. 4188Chichibu, S., Azuhata, T., Sota, T., Nakamura, S., (1997) Appl. Phys. Lett., 70, p. 2822O'donnell, K.P., Martin, R.W., Middleton, P.G., (1999) Phys. Rev. Lett., 82, p. 237Husberg, O., Khartchenko, A., As, D.J., Vogelsang, H., Frey, T., Schikora, D., Lischka, K., Leite, J.R., (2001) Appl. Phys. Lett., 79, p. 1243Tabata, A., Teles, L.K., Scolfaro, L.M.R., Leite, J.R., Kharchenko, A., Frey, T., As, D.J., Bechstedt, F., (2002) Appl. Phys. Lett., 80, p. 769Behbehani, M.K., Piner, E.L., Liu, S.X., El-Masry, N.A., Bedair, S.M., (1999) Appl. Phys. Lett., 75, p. 2202Ruterana, P., Nouet, G., Der Stricht, W.V., Moerman, I., Considine, L., (1998) Appl. Phys. Lett., 72, p. 1742Teles, L.K., Furthmüller, J., Scolfaro, L.M.R., Leite, J.R., Bechstedt, F., (2000) Phys. Rev., B62, p. 2475Teles, L.K., Furthmüller, J., Scolfaro, L.M.R., Leite, J.R., Bechstedt, F., (2001) Phys. Rev., B63, p. 085204Teles, L.K., Scolfaro, L.M.R., Furthmüller, J., Leite, J.R., Bechstedt, F., (2002) J. Appl. Phys., 92, p. 7109Teles, L.K., Ferreira, L.G., Leite, J.R., Scolfaro, L.M.R., Kharchenko, A., Husberg, O., As, D.J., Lischka, K., (2003) Appl. Phys. Lett., 82, p. 4274Marques, M., Teles, L.K., Scolfaro, L.M.R., Leite, J.R., Furthmüller, J., Bechstedt, F., (2003) Appl. Phys. Lett., 83, p. 890Kresse, G., Furthmüller, J., (1996) Comput. Mat. Sci., 6, p. 15Kresse, G., Furthmüller, J., (1996) Phys. Rev., B54, p. 11169Silveira, E., Tabata, A., Leite, J.R., Trentin, R., Lemos, V., Frey, T., As, D.J., Lischka, K., (1999) Appl. Phys. Lett., 75, p. 3602Zunger, A., (1994) Handbook of Crystal Growth, 3, p. 998. , Hurle D.T.J.(Ed.), Amsterdam: ElsevierFerreira, L.G., Wei, S.-H., Zunger, A., (1991) Int. J. Supercomp. Appl., 5, p. 34Mcintosh, F.G., Boutros, K.S., Roberts, J.C., Bedair, S.M., Piner, E.L., El-Masry, N.A., (1996) Appl. Phys. Lett., 68, p. 40Aumer, M.E., Leboeuf, S.F., Mcintosh, F.G., Bedair, S.M., (1999) Appl. Phys. Lett., 75, p. 331

Carbon-Based Defects in GaN: Doping Behaviour

We present first-principles calculations for the substitutional carbon impurity on the nitrogen and gallium sites, and substitutional and split-interstitial dicarbon pairs (2C) in cubic GaN. The pseu-dopotential approach and a plane-wave expansion are applied in the framework of density func-tional theory (DFT) and local density approximation (LDA). The stability of carbon-based defects versus the Fermi level and preparation conditions is analysed. Calculations taking into account several impurities and native defects in their charge states are performed in order to determine the defect which is formed at the highest concentration. The results provide information about consequences of carbon doping in cubic GaN. They are used to elucidate the compensation mechanism seemingly observed with the increment of the high carbon concentrations in recent experiments. Introduction Recent developments in group-III nitrides have resulted in successful fabrication of optical devices based on GaN. The quality of the devices relies in part on the control of doping properties. Magnesium has been traditionally used to obtain p-type doping in GaN, but it has some disadvantages such as high vapour pressure, tendency to segregation, migration on the growing surface, and low ionization ratio a