The Experts below are selected from a list of 111 Experts worldwide ranked by ideXlab platform

Settimio Mobilio - One of the best experts on this subject based on the ideXlab platform.

  • Comparison between experimental and theoretical determination of the local structure of the GaAs1˛yNy Dilute Nitride Alloy
    Physical Review B, 2005
    Co-Authors: Gianluca Ciatto, Vincenzo Fiorentini, Francesco D'acapito, S. Sanna, Antonio Polimeni, Mario Capizzi, Settimio Mobilio, Federico Boscherini
    Abstract:

    We present a combined experimental and theoretical study of the local structure of the $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}y}{\mathrm{N}}_{y}$ Dilute Nitride Alloy. Experimental results obtained by x-ray absorption spectroscopy have been compared with first-principles density-functional supercell calculations and with the predictions of three different valence force field models. Both experiments and calculations find that inclusion of N induces static disorder in the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length distribution. An increase of the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length upon N incorporation in gallium arsenide has been observed; this is due to the competing effects of the decrease of the free lattice parameter and the tensile strain due to pseudomorphic growth. The different theoretical calculations reproduce more or less accurately this bond length expansion; we discuss the performance of the different valence force field models in predicting the measured bond lengths.

  • comparison between experimental and theoretical determination of the local structure of the gaas1 yny Dilute Nitride Alloy
    Physical Review B, 2005
    Co-Authors: Gianluca Ciatto, Vincenzo Fiorentini, S. Sanna, Antonio Polimeni, Mario Capizzi, Settimio Mobilio, F Dacapito, Federico Boscherini
    Abstract:

    We present a combined experimental and theoretical study of the local structure of the $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}y}{\mathrm{N}}_{y}$ Dilute Nitride Alloy. Experimental results obtained by x-ray absorption spectroscopy have been compared with first-principles density-functional supercell calculations and with the predictions of three different valence force field models. Both experiments and calculations find that inclusion of N induces static disorder in the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length distribution. An increase of the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length upon N incorporation in gallium arsenide has been observed; this is due to the competing effects of the decrease of the free lattice parameter and the tensile strain due to pseudomorphic growth. The different theoretical calculations reproduce more or less accurately this bond length expansion; we discuss the performance of the different valence force field models in predicting the measured bond lengths.

  • Comparison between experimental and theoretical determination of the local structure of the GaAsN Dilute Nitride Alloy
    2005
    Co-Authors: Gianluca Ciatto, Vincenzo Fiorentini, Francesco D'acapito, S. Sanna, Antonio Polimeni, Mario Capizzi, Settimio Mobilio, Boscherini F.
    Abstract:

    We present a combined experimental and theoretical study of the local structure of a Dilute Nitride Alloy, GaAs$_{1-y}$N$_y$. Experimental results obtained by X-ray Absorption Spectroscopy have been compared with first-principles density-functional supercell calculations and with the predictions of different Valence Force Field models. Both experiments and calculations find that inclusion of N induces static disorder in the Ga-As bond length distribution. An increase in the Ga-As bond length with N concentration is found; this is due to the competing effects of the decrease of the free lattice parameter and of tensile strain due to pseudomorphic growth. A good agreement between the experimental and theoretical determination of the bond length expansion is found. We discuss the performance of the Valence Force Field models in predicting the bond length expansion

  • Quantitative determination of short-range ordering inInxGa1−xAs1−yNy
    Physical Review B, 2003
    Co-Authors: Gianluca Ciatto, Francesco D'acapito, L. Grenouillet, H. Mariette, D. De Salvador, Gabriele Bisognin, R. Carboni, L. Floreano, R. Gotter, Settimio Mobilio
    Abstract:

    Short-range ordering in the form of an excess of In-N bonds with respect to the random case has been recently predicted for the Dilute Nitride Alloy In x Ga 1 - x As 1 - y N y . This ordering induces a blue shift of the optical band gap and could represent a fundamental materials limitation. In this report we provide a quantitative determination of the effect of annealing on the short-range ordering in In x Ga 1 - x As 1 - y N y , using x-ray-absorption spectroscopy and state-of-the-art analysis methods. We find that in annealed samples short-range ordering is weak, one order of magnitude smaller than predicted.

Amalia Patanè - One of the best experts on this subject based on the ideXlab platform.

  • Hot electron transport and impact ionization in the narrow energy gap InAs1-xNx Alloy.
    Applied Physics Letters, 2010
    Co-Authors: Oleg Makarovsky, Amalia Patanè, Laurence Eaves, Anthony Krier, W. H. M. Feu, Qiandong Zhuang, Richard Beanland, R. J. Airey
    Abstract:

    We report an experimental study of hot electron dynamics in the narrow band gap Dilute Nitride Alloy, InAs1−xNx, with x up to 0.6%. The sharp increase in the conductivity of n-type InAs1−xNx at applied electric fields above 1 kV/cm demonstrates that impact ionization dominates the hot electron dynamics. This observation, combined with the reduction in the band gap energy by the N-atoms, suggest prospects for the use of this narrow gap Alloy in infrared avalanche photodiodes.

  • Tailoring the electrical conductivity of GaAs by nitrogen incorporation.
    Journal of physics. Condensed matter : an Institute of Physics journal, 2009
    Co-Authors: Amalia Patanè, Laurence Eaves, Mark Hopkinson, G. Hill, Giles Allison, A Ignatov
    Abstract:

    We investigate the electrical conductivity of the Dilute Nitride Alloy GaAs1−xNx, focusing on the range of concentrations of N over which this material system behaves as a good conductor. We report a large increase of the resistivity for x>0.2% and a strong reduction of the electron mobility, μ, at x~0.1%. In the ultra-Dilute regime (x~0.1%) and at low electric fields ( 1 kV cm−1), the conduction electrons gain sufficient energy to approach the energy of the resonant N level, where they become spatially localized. This resonant electron localization in an electric field (RELIEF) leads to negative differential velocity. The RELIEF effect could be observed in other III–N–V compounds, such as InAs1−xNx and InP1−xNx, and has potential for applications in terahertz electronics.

  • Electron coherence length and mobility in highly mismatched III-N-V Alloys
    Applied Physics Letters, 2008
    Co-Authors: Amalia Patanè, Laurence Eaves, N. V. Kozlova, Mark Hopkinson, Anthony Krier, Qiandong Zhuang, Giles Allison, G. Hill
    Abstract:

    We investigate the quantum coherence length, Lφ, and mobility of conduction electrons in the Dilute Nitride Alloy GaAs1−xNx. Analysis of the negative magnetoresistance using weak localization theory reveals a marked reduction in Lφ with increasing N-content. Our data are compared to theoretical models of electronic transport in GaAs1−xNx and discussed in terms of the unusual type of compositional disorder exhibited by III-N-V Alloys. A comparative study of the electron mobility in InAs1−xNx also indicates that disorder effects are significantly weaker in this small band gap material.

  • Electron effective mass and Si-donor binding energy in Ga As 1 − x N x probed by a high magnetic field
    Physical Review B, 2008
    Co-Authors: G. Allison, Amalia Patanè, S. Spasov, Laurence Eaves, N. V. Kozlova, J. Freudenberger, Mark Hopkinson, G. Hill
    Abstract:

    We study the magnetoresistance of the Dilute Nitride Alloy $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ in magnetic fields up to $47\phantom{\rule{0.3em}{0ex}}\mathrm{T}$. We observe a strong magnetophonon resonance effect and a large transverse magnetoresistance, which provide the means of measuring the N-induced enhancement of the electron effective mass and of investigating the magnetic freeze-out of conduction electrons on Si donors in $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$.

  • electron effective mass and si donor binding energy in ga as 1 x n x probed by a high magnetic field
    Physical Review B, 2008
    Co-Authors: G. Allison, Amalia Patanè, S. Spasov, Laurence Eaves, N. V. Kozlova, J. Freudenberger, Mark Hopkinson, G. Hill
    Abstract:

    We study the magnetoresistance of the Dilute Nitride Alloy $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ in magnetic fields up to $47\phantom{\rule{0.3em}{0ex}}\mathrm{T}$. We observe a strong magnetophonon resonance effect and a large transverse magnetoresistance, which provide the means of measuring the N-induced enhancement of the electron effective mass and of investigating the magnetic freeze-out of conduction electrons on Si donors in $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$.

G. Hill - One of the best experts on this subject based on the ideXlab platform.

  • Tailoring the electrical conductivity of GaAs by nitrogen incorporation.
    Journal of physics. Condensed matter : an Institute of Physics journal, 2009
    Co-Authors: Amalia Patanè, Laurence Eaves, Mark Hopkinson, G. Hill, Giles Allison, A Ignatov
    Abstract:

    We investigate the electrical conductivity of the Dilute Nitride Alloy GaAs1−xNx, focusing on the range of concentrations of N over which this material system behaves as a good conductor. We report a large increase of the resistivity for x>0.2% and a strong reduction of the electron mobility, μ, at x~0.1%. In the ultra-Dilute regime (x~0.1%) and at low electric fields ( 1 kV cm−1), the conduction electrons gain sufficient energy to approach the energy of the resonant N level, where they become spatially localized. This resonant electron localization in an electric field (RELIEF) leads to negative differential velocity. The RELIEF effect could be observed in other III–N–V compounds, such as InAs1−xNx and InP1−xNx, and has potential for applications in terahertz electronics.

  • Electron coherence length and mobility in highly mismatched III-N-V Alloys
    Applied Physics Letters, 2008
    Co-Authors: Amalia Patanè, Laurence Eaves, N. V. Kozlova, Mark Hopkinson, Anthony Krier, Qiandong Zhuang, Giles Allison, G. Hill
    Abstract:

    We investigate the quantum coherence length, Lφ, and mobility of conduction electrons in the Dilute Nitride Alloy GaAs1−xNx. Analysis of the negative magnetoresistance using weak localization theory reveals a marked reduction in Lφ with increasing N-content. Our data are compared to theoretical models of electronic transport in GaAs1−xNx and discussed in terms of the unusual type of compositional disorder exhibited by III-N-V Alloys. A comparative study of the electron mobility in InAs1−xNx also indicates that disorder effects are significantly weaker in this small band gap material.

  • Electron effective mass and Si-donor binding energy in Ga As 1 − x N x probed by a high magnetic field
    Physical Review B, 2008
    Co-Authors: G. Allison, Amalia Patanè, S. Spasov, Laurence Eaves, N. V. Kozlova, J. Freudenberger, Mark Hopkinson, G. Hill
    Abstract:

    We study the magnetoresistance of the Dilute Nitride Alloy $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ in magnetic fields up to $47\phantom{\rule{0.3em}{0ex}}\mathrm{T}$. We observe a strong magnetophonon resonance effect and a large transverse magnetoresistance, which provide the means of measuring the N-induced enhancement of the electron effective mass and of investigating the magnetic freeze-out of conduction electrons on Si donors in $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$.

  • electron effective mass and si donor binding energy in ga as 1 x n x probed by a high magnetic field
    Physical Review B, 2008
    Co-Authors: G. Allison, Amalia Patanè, S. Spasov, Laurence Eaves, N. V. Kozlova, J. Freudenberger, Mark Hopkinson, G. Hill
    Abstract:

    We study the magnetoresistance of the Dilute Nitride Alloy $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ in magnetic fields up to $47\phantom{\rule{0.3em}{0ex}}\mathrm{T}$. We observe a strong magnetophonon resonance effect and a large transverse magnetoresistance, which provide the means of measuring the N-induced enhancement of the electron effective mass and of investigating the magnetic freeze-out of conduction electrons on Si donors in $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$.

Gianluca Ciatto - One of the best experts on this subject based on the ideXlab platform.

  • Comparison between experimental and theoretical determination of the local structure of the GaAs1˛yNy Dilute Nitride Alloy
    Physical Review B, 2005
    Co-Authors: Gianluca Ciatto, Vincenzo Fiorentini, Francesco D'acapito, S. Sanna, Antonio Polimeni, Mario Capizzi, Settimio Mobilio, Federico Boscherini
    Abstract:

    We present a combined experimental and theoretical study of the local structure of the $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}y}{\mathrm{N}}_{y}$ Dilute Nitride Alloy. Experimental results obtained by x-ray absorption spectroscopy have been compared with first-principles density-functional supercell calculations and with the predictions of three different valence force field models. Both experiments and calculations find that inclusion of N induces static disorder in the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length distribution. An increase of the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length upon N incorporation in gallium arsenide has been observed; this is due to the competing effects of the decrease of the free lattice parameter and the tensile strain due to pseudomorphic growth. The different theoretical calculations reproduce more or less accurately this bond length expansion; we discuss the performance of the different valence force field models in predicting the measured bond lengths.

  • comparison between experimental and theoretical determination of the local structure of the gaas1 yny Dilute Nitride Alloy
    Physical Review B, 2005
    Co-Authors: Gianluca Ciatto, Vincenzo Fiorentini, S. Sanna, Antonio Polimeni, Mario Capizzi, Settimio Mobilio, F Dacapito, Federico Boscherini
    Abstract:

    We present a combined experimental and theoretical study of the local structure of the $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}y}{\mathrm{N}}_{y}$ Dilute Nitride Alloy. Experimental results obtained by x-ray absorption spectroscopy have been compared with first-principles density-functional supercell calculations and with the predictions of three different valence force field models. Both experiments and calculations find that inclusion of N induces static disorder in the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length distribution. An increase of the $\mathrm{Ga}\text{\ensuremath{-}}\mathrm{As}$ bond length upon N incorporation in gallium arsenide has been observed; this is due to the competing effects of the decrease of the free lattice parameter and the tensile strain due to pseudomorphic growth. The different theoretical calculations reproduce more or less accurately this bond length expansion; we discuss the performance of the different valence force field models in predicting the measured bond lengths.

  • Comparison between experimental and theoretical determination of the local structure of the GaAsN Dilute Nitride Alloy
    2005
    Co-Authors: Gianluca Ciatto, Vincenzo Fiorentini, Francesco D'acapito, S. Sanna, Antonio Polimeni, Mario Capizzi, Settimio Mobilio, Boscherini F.
    Abstract:

    We present a combined experimental and theoretical study of the local structure of a Dilute Nitride Alloy, GaAs$_{1-y}$N$_y$. Experimental results obtained by X-ray Absorption Spectroscopy have been compared with first-principles density-functional supercell calculations and with the predictions of different Valence Force Field models. Both experiments and calculations find that inclusion of N induces static disorder in the Ga-As bond length distribution. An increase in the Ga-As bond length with N concentration is found; this is due to the competing effects of the decrease of the free lattice parameter and of tensile strain due to pseudomorphic growth. A good agreement between the experimental and theoretical determination of the bond length expansion is found. We discuss the performance of the Valence Force Field models in predicting the bond length expansion

  • Quantitative determination of short-range ordering inInxGa1−xAs1−yNy
    Physical Review B, 2003
    Co-Authors: Gianluca Ciatto, Francesco D'acapito, L. Grenouillet, H. Mariette, D. De Salvador, Gabriele Bisognin, R. Carboni, L. Floreano, R. Gotter, Settimio Mobilio
    Abstract:

    Short-range ordering in the form of an excess of In-N bonds with respect to the random case has been recently predicted for the Dilute Nitride Alloy In x Ga 1 - x As 1 - y N y . This ordering induces a blue shift of the optical band gap and could represent a fundamental materials limitation. In this report we provide a quantitative determination of the effect of annealing on the short-range ordering in In x Ga 1 - x As 1 - y N y , using x-ray-absorption spectroscopy and state-of-the-art analysis methods. We find that in annealed samples short-range ordering is weak, one order of magnitude smaller than predicted.

Laurence Eaves - One of the best experts on this subject based on the ideXlab platform.

  • Hot electron transport and impact ionization in the narrow energy gap InAs1-xNx Alloy.
    Applied Physics Letters, 2010
    Co-Authors: Oleg Makarovsky, Amalia Patanè, Laurence Eaves, Anthony Krier, W. H. M. Feu, Qiandong Zhuang, Richard Beanland, R. J. Airey
    Abstract:

    We report an experimental study of hot electron dynamics in the narrow band gap Dilute Nitride Alloy, InAs1−xNx, with x up to 0.6%. The sharp increase in the conductivity of n-type InAs1−xNx at applied electric fields above 1 kV/cm demonstrates that impact ionization dominates the hot electron dynamics. This observation, combined with the reduction in the band gap energy by the N-atoms, suggest prospects for the use of this narrow gap Alloy in infrared avalanche photodiodes.

  • Tailoring the electrical conductivity of GaAs by nitrogen incorporation.
    Journal of physics. Condensed matter : an Institute of Physics journal, 2009
    Co-Authors: Amalia Patanè, Laurence Eaves, Mark Hopkinson, G. Hill, Giles Allison, A Ignatov
    Abstract:

    We investigate the electrical conductivity of the Dilute Nitride Alloy GaAs1−xNx, focusing on the range of concentrations of N over which this material system behaves as a good conductor. We report a large increase of the resistivity for x>0.2% and a strong reduction of the electron mobility, μ, at x~0.1%. In the ultra-Dilute regime (x~0.1%) and at low electric fields ( 1 kV cm−1), the conduction electrons gain sufficient energy to approach the energy of the resonant N level, where they become spatially localized. This resonant electron localization in an electric field (RELIEF) leads to negative differential velocity. The RELIEF effect could be observed in other III–N–V compounds, such as InAs1−xNx and InP1−xNx, and has potential for applications in terahertz electronics.

  • Electron coherence length and mobility in highly mismatched III-N-V Alloys
    Applied Physics Letters, 2008
    Co-Authors: Amalia Patanè, Laurence Eaves, N. V. Kozlova, Mark Hopkinson, Anthony Krier, Qiandong Zhuang, Giles Allison, G. Hill
    Abstract:

    We investigate the quantum coherence length, Lφ, and mobility of conduction electrons in the Dilute Nitride Alloy GaAs1−xNx. Analysis of the negative magnetoresistance using weak localization theory reveals a marked reduction in Lφ with increasing N-content. Our data are compared to theoretical models of electronic transport in GaAs1−xNx and discussed in terms of the unusual type of compositional disorder exhibited by III-N-V Alloys. A comparative study of the electron mobility in InAs1−xNx also indicates that disorder effects are significantly weaker in this small band gap material.

  • Electron effective mass and Si-donor binding energy in Ga As 1 − x N x probed by a high magnetic field
    Physical Review B, 2008
    Co-Authors: G. Allison, Amalia Patanè, S. Spasov, Laurence Eaves, N. V. Kozlova, J. Freudenberger, Mark Hopkinson, G. Hill
    Abstract:

    We study the magnetoresistance of the Dilute Nitride Alloy $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ in magnetic fields up to $47\phantom{\rule{0.3em}{0ex}}\mathrm{T}$. We observe a strong magnetophonon resonance effect and a large transverse magnetoresistance, which provide the means of measuring the N-induced enhancement of the electron effective mass and of investigating the magnetic freeze-out of conduction electrons on Si donors in $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$.

  • electron effective mass and si donor binding energy in ga as 1 x n x probed by a high magnetic field
    Physical Review B, 2008
    Co-Authors: G. Allison, Amalia Patanè, S. Spasov, Laurence Eaves, N. V. Kozlova, J. Freudenberger, Mark Hopkinson, G. Hill
    Abstract:

    We study the magnetoresistance of the Dilute Nitride Alloy $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$ in magnetic fields up to $47\phantom{\rule{0.3em}{0ex}}\mathrm{T}$. We observe a strong magnetophonon resonance effect and a large transverse magnetoresistance, which provide the means of measuring the N-induced enhancement of the electron effective mass and of investigating the magnetic freeze-out of conduction electrons on Si donors in $\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}$.