The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
C J Humphreys - One of the best experts on this subject based on the ideXlab platform.
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determination of relative internal Quantum Efficiency in ingan gan Quantum wells
Journal of Applied Physics, 2005Co-Authors: C E Martinez, N M Stanton, D M Graham, Menno J. Kappers, P Dawson, A. J. Kent, C J HumphreysAbstract:We have investigated the relative Quantum Efficiency in a series of InGaN∕GaN single Quantum wells with differing indium concentration. The results of measurements involving direct detection of phonons emitted as a result of nonradiative recombination and carrier energy relaxation are compared with time-resolved photoluminescence studies. Using these complementary techniques we have extracted the low-temperature internal Quantum Efficiency of the recombination and observed the effect of free-carrier screening on the radiative and nonradiative processes in the Quantum well samples. All the samples exhibit high Quantum Efficiency, with the maximum being observed in the 10% indium sample. In addition, we observe the appearance of a delayed phonon signal, which we correlate to the measured Quantum Efficiency of the samples.
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Determination of relative internal Quantum Efficiency in InGaN∕GaN Quantum wells
Journal of Applied Physics, 2005Co-Authors: C E Martinez, N M Stanton, D M Graham, Menno J. Kappers, P Dawson, A. J. Kent, C J HumphreysAbstract:We have investigated the relative Quantum Efficiency in a series of InGaN∕GaN single Quantum wells with differing indium concentration. The results of measurements involving direct detection of phonons emitted as a result of nonradiative recombination and carrier energy relaxation are compared with time-resolved photoluminescence studies. Using these complementary techniques we have extracted the low-temperature internal Quantum Efficiency of the recombination and observed the effect of free-carrier screening on the radiative and nonradiative processes in the Quantum well samples. All the samples exhibit high Quantum Efficiency, with the maximum being observed in the 10% indium sample. In addition, we observe the appearance of a delayed phonon signal, which we correlate to the measured Quantum Efficiency of the samples.
C E Martinez - One of the best experts on this subject based on the ideXlab platform.
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determination of relative internal Quantum Efficiency in ingan gan Quantum wells
Journal of Applied Physics, 2005Co-Authors: C E Martinez, N M Stanton, D M Graham, Menno J. Kappers, P Dawson, A. J. Kent, C J HumphreysAbstract:We have investigated the relative Quantum Efficiency in a series of InGaN∕GaN single Quantum wells with differing indium concentration. The results of measurements involving direct detection of phonons emitted as a result of nonradiative recombination and carrier energy relaxation are compared with time-resolved photoluminescence studies. Using these complementary techniques we have extracted the low-temperature internal Quantum Efficiency of the recombination and observed the effect of free-carrier screening on the radiative and nonradiative processes in the Quantum well samples. All the samples exhibit high Quantum Efficiency, with the maximum being observed in the 10% indium sample. In addition, we observe the appearance of a delayed phonon signal, which we correlate to the measured Quantum Efficiency of the samples.
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Determination of relative internal Quantum Efficiency in InGaN∕GaN Quantum wells
Journal of Applied Physics, 2005Co-Authors: C E Martinez, N M Stanton, D M Graham, Menno J. Kappers, P Dawson, A. J. Kent, C J HumphreysAbstract:We have investigated the relative Quantum Efficiency in a series of InGaN∕GaN single Quantum wells with differing indium concentration. The results of measurements involving direct detection of phonons emitted as a result of nonradiative recombination and carrier energy relaxation are compared with time-resolved photoluminescence studies. Using these complementary techniques we have extracted the low-temperature internal Quantum Efficiency of the recombination and observed the effect of free-carrier screening on the radiative and nonradiative processes in the Quantum well samples. All the samples exhibit high Quantum Efficiency, with the maximum being observed in the 10% indium sample. In addition, we observe the appearance of a delayed phonon signal, which we correlate to the measured Quantum Efficiency of the samples.
Yu Duan - One of the best experts on this subject based on the ideXlab platform.
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Simulation of transform for external Quantum Efficiency and power Efficiency of electroluminescent devices
Journal of Luminescence, 2006Co-Authors: Changhai Zhang, Yu DuanAbstract:We report on the rough methods of transforming external Quantum Efficiency and power Efficiency of organic light-emitting devices (OLEDs). The calculation system based on supposing a perfectly diffuse electroluminescent lambertian surface can be useful for appraising external Quantum Efficiency and power Efficiency in research work and we set up model of transformation for external Quantum Efficiency and power Efficiency of OLEDs and develop computer program to simulate scaling modulus.
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Modeling of transform for external Quantum Efficiency and power Efficiency of electroluminescent devices
Optomechatronic Micro Nano Devices and Components, 2005Co-Authors: Huiying Li, Changhai Zhang, Dechang Li, Yu DuanAbstract:We report on the rough methods for transforming of external Quantum Efficiency and power Efficiency of organic light-emitting devices (OLEDs). The calculation system based on supposing a perfectly diffuse electroluminescent lambertian surface can be useful for appraising external Quantum Efficiency and power Efficiency in research work. And we set up model of transform for external Quantum Efficiency and power Efficiency of OLEDs and develop computer program to simulate scaling modulus.
Elison Matioli - One of the best experts on this subject based on the ideXlab platform.
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Internal Quantum Efficiency in Light-Emitting Diodes
Topics in Applied Physics, 2017Co-Authors: Elison Matioli, Claude WeisbuchAbstract:In this chapter, we present different techniques used to assess the internal Quantum Efficiency (IQE) in light-emitting diodes (LEDs). The commonly used technique based on temperature-dependent photoluminescence relies in strong assumptions which are discussed in this chapter.
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high internal and external Quantum Efficiency ingan gan solar cells
Applied Physics Letters, 2011Co-Authors: Elison Matioli, Carl J. Neufeld, Samantha C. Cruz, Steven P. Denbaars, Robert M Farrell, Stacia Keller, Xu Chen, Ali A Alheji, U K Mishra, Shuji NakamuraAbstract:High internal and external Quantum Efficiency GaN/InGaN solar cells are demonstrated. The internal Quantum Efficiency was assessed through the combination of absorption and external Quantum Efficiency measurements. The measured internal Quantum Efficiency, as high as 97%, revealed an efficient conversion of absorbed photons into electrons and holes and an efficient transport of these carriers outside the device. Improved light incoupling into the solar cells was achieved by texturing the surface. A peak external Quantum Efficiency of 72%, a fill factor of 79%, a short-circuit current density of 1.06 mA/cm2, and an open circuit voltage of 1.89 V were achieved under 1 sun air-mass 1.5 global spectrum illumination conditions.
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High internal and external Quantum Efficiency InGaN/GaN solar cells
Applied Physics Letters, 2011Co-Authors: Elison Matioli, Carl J. Neufeld, Samantha C. Cruz, Ali A. Al-heji, M. Iza, Steven Denbaars, Steven P. Denbaars, Robert M Farrell, Stacia Keller, Xu Chen, Umesh MishraAbstract:High internal and external Quantum Efficiency GaN/InGaN solar cells are demonstrated. The internal Quantum Efficiency was assessed through the combination of absorption and external Quantum Efficiency measurements. The measured internal Quantum Efficiency, as high as 97%, revealed an efficient conversion of absorbed photons into electrons and holes and an efficient transport of these carriers outside the device. Improved light incoupling into the solar cells was achieved by texturing the surface. A peak external Quantum Efficiency of 72%, a fill factor of 79%, a short-circuit current density of 1.06 mA / cm 2 , and an open circuit voltage of 1.89 V were achieved under 1 sun air-mass 1.5 global spectrumillumination conditions.
Umesh Mishra - One of the best experts on this subject based on the ideXlab platform.
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High internal and external Quantum Efficiency InGaN/GaN solar cells
Applied Physics Letters, 2011Co-Authors: Elison Matioli, Carl J. Neufeld, Samantha C. Cruz, Ali A. Al-heji, M. Iza, Steven Denbaars, Steven P. Denbaars, Robert M Farrell, Stacia Keller, Xu Chen, Umesh MishraAbstract:High internal and external Quantum Efficiency GaN/InGaN solar cells are demonstrated. The internal Quantum Efficiency was assessed through the combination of absorption and external Quantum Efficiency measurements. The measured internal Quantum Efficiency, as high as 97%, revealed an efficient conversion of absorbed photons into electrons and holes and an efficient transport of these carriers outside the device. Improved light incoupling into the solar cells was achieved by texturing the surface. A peak external Quantum Efficiency of 72%, a fill factor of 79%, a short-circuit current density of 1.06 mA / cm 2 , and an open circuit voltage of 1.89 V were achieved under 1 sun air-mass 1.5 global spectrumillumination conditions.
