The Experts below are selected from a list of 25338 Experts worldwide ranked by ideXlab platform

Olivier Briot - One of the best experts on this subject based on the ideXlab platform.

  • Deep ultraviolet Raman scattering for the monitoring of high-temperature processing of AlGaN
    1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, David N. Batchelder, Olivier Briot
    Abstract:

    Deep ultraviolet micro-Raman scattering was employed to monitor high-temperature processing of AlGaN films under resonant excitation conditions, giving rise to enhanced first and second-order Raman scattering. High-temperature treatments at 1100 degrees C result in changes in the second-order Raman scattering signal and monitor the emergence of microscopic defects during the high-temperature processing. The second-order Raman spectrum was analyzed to gain insight into the AlGaN phonon density of states. For annealing temperatures higher than 1150 degrees C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1-xN phase emerge. At 1100 degrees C, prior to the Al0.72Ga0.28N deComposition, deep UV Raman scattering detects the built-up of strain in the Al0.72Ga0.28N film.

  • Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering
    Applied Physics Letters, 1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, H. S. Sands, David N. Batchelder, S. Clur, Olivier Briot
    Abstract:

    We have illustrated the use of ultraviolet (UV) Raman scattering to investigate the thermal stability of AlGaN layers with high-Aluminum content. The degradation pathway of Al0.72Ga0.28N was monitored for high-temperature treatments up to 1200 °C. For annealing temperatures higher than 1150 °C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1−xN phase emerge. At 1100 °C, prior to the Al0.72Ga0.28N deComposition, UV Raman scattering detects the buildup of a large strain in the Al0.72Ga0.28N film. The crystalline quality of Al0.72Ga0.28N is unaffected up to 1000 °C.

  • Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering
    Applied Physics Letters, 1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, David N. Batchelder, H. Sands, Sandra Ruffenach, Olivier Briot
    Abstract:

    We have illustrated the use of ultraviolet (UV) Raman scattering to investigate the thermal stability of AlGaN layers with high-Aluminum content. The degradation pathway of Al0.72Ga0.28N was monitored for high-temperature treatments up to 1200 degrees C. For annealing temperatures higher than 1150 degrees C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1-xN phase emerge. At 1100 degrees C, prior to the Al0.72Ga0.28N deComposition, UV Raman scattering detects the buildup of a large strain in the Al0.72Ga0.28N film The crystalline quality of Al0.72Ga0.28N is unaffected up to 1000 degrees C. (C) 1999 American Institute of Physics. [S0003-6951(99)00704-4].

H X Jiang - One of the best experts on this subject based on the ideXlab platform.

  • algan based ultraviolet light emitting diodes grown on aln epilayers
    Applied Physics Letters, 2004
    Co-Authors: M Khizar, M L Nakarmi, H X Jiang
    Abstract:

    AlGaN-based deep-ultraviolet light-emitting diode (LED) structures, which radiate light at 305 and 290nm, have been grown on sapphire substrates using an AlN epilayer template. The fabricated devices have a circular geometry to enhance current spreading and light extraction. Circular UV LEDs of different sizes have been characterized. It was found that smaller disk LEDs had higher saturation optical power densities but lower optical powers than the larger devices. This trade-off between power and power density is a result of a compromise between electrical and thermal resistance, as well as the current crowding effect (which is due to the low electrical conductivity of high Aluminum Composition n- and p‐AlGaN layers). Disk UV LEDs should thus have a moderate size to best utilize both total optical power and power density. For 0.85mm×0.85mm interdigitated LEDs, a saturation optical power of 2.9mW (1.8mW) at 305nm (290nm) was also obtained under dc operation.

Martin Kuball - One of the best experts on this subject based on the ideXlab platform.

  • Deep ultraviolet Raman scattering for the monitoring of high-temperature processing of AlGaN
    1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, David N. Batchelder, Olivier Briot
    Abstract:

    Deep ultraviolet micro-Raman scattering was employed to monitor high-temperature processing of AlGaN films under resonant excitation conditions, giving rise to enhanced first and second-order Raman scattering. High-temperature treatments at 1100 degrees C result in changes in the second-order Raman scattering signal and monitor the emergence of microscopic defects during the high-temperature processing. The second-order Raman spectrum was analyzed to gain insight into the AlGaN phonon density of states. For annealing temperatures higher than 1150 degrees C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1-xN phase emerge. At 1100 degrees C, prior to the Al0.72Ga0.28N deComposition, deep UV Raman scattering detects the built-up of strain in the Al0.72Ga0.28N film.

  • Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering
    Applied Physics Letters, 1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, H. S. Sands, David N. Batchelder, S. Clur, Olivier Briot
    Abstract:

    We have illustrated the use of ultraviolet (UV) Raman scattering to investigate the thermal stability of AlGaN layers with high-Aluminum content. The degradation pathway of Al0.72Ga0.28N was monitored for high-temperature treatments up to 1200 °C. For annealing temperatures higher than 1150 °C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1−xN phase emerge. At 1100 °C, prior to the Al0.72Ga0.28N deComposition, UV Raman scattering detects the buildup of a large strain in the Al0.72Ga0.28N film. The crystalline quality of Al0.72Ga0.28N is unaffected up to 1000 °C.

  • Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering
    Applied Physics Letters, 1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, David N. Batchelder, H. Sands, Sandra Ruffenach, Olivier Briot
    Abstract:

    We have illustrated the use of ultraviolet (UV) Raman scattering to investigate the thermal stability of AlGaN layers with high-Aluminum content. The degradation pathway of Al0.72Ga0.28N was monitored for high-temperature treatments up to 1200 degrees C. For annealing temperatures higher than 1150 degrees C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1-xN phase emerge. At 1100 degrees C, prior to the Al0.72Ga0.28N deComposition, UV Raman scattering detects the buildup of a large strain in the Al0.72Ga0.28N film The crystalline quality of Al0.72Ga0.28N is unaffected up to 1000 degrees C. (C) 1999 American Institute of Physics. [S0003-6951(99)00704-4].

M Khizar - One of the best experts on this subject based on the ideXlab platform.

  • algan based ultraviolet light emitting diodes grown on aln epilayers
    Applied Physics Letters, 2004
    Co-Authors: M Khizar, M L Nakarmi, H X Jiang
    Abstract:

    AlGaN-based deep-ultraviolet light-emitting diode (LED) structures, which radiate light at 305 and 290nm, have been grown on sapphire substrates using an AlN epilayer template. The fabricated devices have a circular geometry to enhance current spreading and light extraction. Circular UV LEDs of different sizes have been characterized. It was found that smaller disk LEDs had higher saturation optical power densities but lower optical powers than the larger devices. This trade-off between power and power density is a result of a compromise between electrical and thermal resistance, as well as the current crowding effect (which is due to the low electrical conductivity of high Aluminum Composition n- and p‐AlGaN layers). Disk UV LEDs should thus have a moderate size to best utilize both total optical power and power density. For 0.85mm×0.85mm interdigitated LEDs, a saturation optical power of 2.9mW (1.8mW) at 305nm (290nm) was also obtained under dc operation.

David N. Batchelder - One of the best experts on this subject based on the ideXlab platform.

  • Deep ultraviolet Raman scattering for the monitoring of high-temperature processing of AlGaN
    1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, David N. Batchelder, Olivier Briot
    Abstract:

    Deep ultraviolet micro-Raman scattering was employed to monitor high-temperature processing of AlGaN films under resonant excitation conditions, giving rise to enhanced first and second-order Raman scattering. High-temperature treatments at 1100 degrees C result in changes in the second-order Raman scattering signal and monitor the emergence of microscopic defects during the high-temperature processing. The second-order Raman spectrum was analyzed to gain insight into the AlGaN phonon density of states. For annealing temperatures higher than 1150 degrees C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1-xN phase emerge. At 1100 degrees C, prior to the Al0.72Ga0.28N deComposition, deep UV Raman scattering detects the built-up of strain in the Al0.72Ga0.28N film.

  • Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering
    Applied Physics Letters, 1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, H. S. Sands, David N. Batchelder, S. Clur, Olivier Briot
    Abstract:

    We have illustrated the use of ultraviolet (UV) Raman scattering to investigate the thermal stability of AlGaN layers with high-Aluminum content. The degradation pathway of Al0.72Ga0.28N was monitored for high-temperature treatments up to 1200 °C. For annealing temperatures higher than 1150 °C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1−xN phase emerge. At 1100 °C, prior to the Al0.72Ga0.28N deComposition, UV Raman scattering detects the buildup of a large strain in the Al0.72Ga0.28N film. The crystalline quality of Al0.72Ga0.28N is unaffected up to 1000 °C.

  • Degradation of AlGaN during high-temperature annealing monitored by ultraviolet Raman scattering
    Applied Physics Letters, 1999
    Co-Authors: Martin Kuball, F. Demangeot, J. Frandon, M. A. Renucci, David N. Batchelder, H. Sands, Sandra Ruffenach, Olivier Briot
    Abstract:

    We have illustrated the use of ultraviolet (UV) Raman scattering to investigate the thermal stability of AlGaN layers with high-Aluminum content. The degradation pathway of Al0.72Ga0.28N was monitored for high-temperature treatments up to 1200 degrees C. For annealing temperatures higher than 1150 degrees C, the Al0.72Ga0.28N film decomposes: a low- and a high-Aluminum Composition AlxGa1-xN phase emerge. At 1100 degrees C, prior to the Al0.72Ga0.28N deComposition, UV Raman scattering detects the buildup of a large strain in the Al0.72Ga0.28N film The crystalline quality of Al0.72Ga0.28N is unaffected up to 1000 degrees C. (C) 1999 American Institute of Physics. [S0003-6951(99)00704-4].