The Experts below are selected from a list of 12036 Experts worldwide ranked by ideXlab platform
Moungi G Bawendi - One of the best experts on this subject based on the ideXlab platform.
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measurement of the size dependent hole spectrum in cdse quantum dots
Physical Review Letters, 1994Co-Authors: David J Norris, A Sacra, Christopher B Murray, Moungi G BawendiAbstract:We combine a new synthesis with transient optical hole burning to observe and assign the size evolution (19 to 115 A diameter, σ<5%) of a series of excited states in CdSe quantum dots. We observe an avoided crossing around the spin orbit energy in the hole spectra for ∼65 A dots, indicating the importance of valence band complexities in the description of the excited states. Comparsion with dc Stark data shows that bleach spectra are consistent with Localized Carrier induced electric fields.
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measurement of the size dependent hole spectrum in cdse quantum dots
Physical Review Letters, 1994Co-Authors: David J Norris, A Sacra, Christopher B Murray, Moungi G BawendiAbstract:We combine a new synthesis with transient optical hole burning to observe and assign the size evolution (19 to 115 \AA{} diameter, \ensuremath{\sigma}5%) of a series of excited states in CdSe quantum dots. We observe an avoided crossing around the spin orbit energy in the hole spectra for \ensuremath{\sim}65 \AA{} dots, indicating the importance of valence band complexities in the description of the excited states. Comparsion with dc Stark data shows that bleach spectra are consistent with Localized Carrier induced electric fields.
David J Norris - One of the best experts on this subject based on the ideXlab platform.
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measurement of the size dependent hole spectrum in cdse quantum dots
Physical Review Letters, 1994Co-Authors: David J Norris, A Sacra, Christopher B Murray, Moungi G BawendiAbstract:We combine a new synthesis with transient optical hole burning to observe and assign the size evolution (19 to 115 A diameter, σ<5%) of a series of excited states in CdSe quantum dots. We observe an avoided crossing around the spin orbit energy in the hole spectra for ∼65 A dots, indicating the importance of valence band complexities in the description of the excited states. Comparsion with dc Stark data shows that bleach spectra are consistent with Localized Carrier induced electric fields.
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measurement of the size dependent hole spectrum in cdse quantum dots
Physical Review Letters, 1994Co-Authors: David J Norris, A Sacra, Christopher B Murray, Moungi G BawendiAbstract:We combine a new synthesis with transient optical hole burning to observe and assign the size evolution (19 to 115 \AA{} diameter, \ensuremath{\sigma}5%) of a series of excited states in CdSe quantum dots. We observe an avoided crossing around the spin orbit energy in the hole spectra for \ensuremath{\sim}65 \AA{} dots, indicating the importance of valence band complexities in the description of the excited states. Comparsion with dc Stark data shows that bleach spectra are consistent with Localized Carrier induced electric fields.
Hirofumi Mino - One of the best experts on this subject based on the ideXlab platform.
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influence of excitation power and temperature on photoluminescence in ingan gan multiple quantum wells
Optics Express, 2012Co-Authors: H Wang, Gang Wang, Yongzhi Jiang, Baoli Liu, Hirofumi MinoAbstract:Excitation power and temperature dependences of the photoluminescence (PL) spectra are studied in InGaN/GaN multiple quantum wells (MQWs). The excitation power dependences of the PL peak energy and linewidth indicate that the emission process of the MQWs is dominated first by the Coulomb screening effect and then by the Localized states filling at low temperature, and that the nonradiative centers are thermally activated in low excitation range at room temperature. The anomalous temperature dependences of the peak energy and linewidth are well explained by the Localized Carrier hopping and thermalization process, and by the exponentially increased density of states with energy in the band tail. Moreover, it is also found that internal quantum efficiency is related to the mechanism conversion from nonradiative to radiative mechanism, and up to the Carriers escaping from Localized states.
Sungjin Kim - One of the best experts on this subject based on the ideXlab platform.
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synergetic enhancement of thermoelectric performances by Localized Carrier and phonon scattering in cu2se with incorporated fullerene nanoparticles
Nanoscale Advances, 2021Co-Authors: Yingshi Jin, Junphil Hwang, Sujin Kim, Jungwon Kim, Sungjin KimAbstract:C60/Cu2Se thermoelectric nanocomposites were synthesized with various amounts of fullerene (C60; 0.03, 0.3, 0.5, 0.7 mol%) incorporated in Cu2Se. The thermoelectric figures of merits (zT) of the C60/Cu2Se nanocomposites were enhanced by 20–30% compared to that of pure Cu2Se, reaching a value of 1.4 at 773 K. The primary cause of zT enhancement is the synergetic effect of thermal conductivity reduction by phonon scattering and Seebeck coefficient increase by Carrier localization that results from incorporation of C60 nanoparticles. Theoretical calculations for Seebeck coefficient enhancement and lattice thermal conductivity reduction were performed. The Seebeck coefficients of C60/Cu2Se nanocomposites were around 43% higher than that of pure Cu2Se, whereas the reduction of lattice thermal conductivity with incorporation of C60 was around 40–50%.
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quantum efficiency affected by Localized Carrier distribution near the v defect in gan based quantum well
Applied Physics Letters, 2013Co-Authors: Yonghee Cho, Junyoun Kim, Jaekyun Kim, Munbo Shim, Sangheum Hwang, Seounghwan Park, Youngsoo Park, Sungjin KimAbstract:It is known that due to the formation of in-plane local energy barrier, V-defects can screen the Carriers which non-radiatively recombine in threading dislocations (TDs) and hence, enhance the internal quantum efficiency in GaN based light-emitting diodes. By a theoretical modeling capable of describing the inhomogeneous Carrier distribution near the V-defect in GaN based quantum wells, we show that the efficient suppression of non-radiative (NR) recombination via TD requires the local energy barrier height of V-defect larger than ∼80 meV. The NR process in TD combined with V-defect influences the quantum efficiency mainly in the low injection current density regime suitably described by the linear dependence of Carrier density. We provide a simple phenomenological expression for the NR recombination rate based on the model result.
Christopher B Murray - One of the best experts on this subject based on the ideXlab platform.
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measurement of the size dependent hole spectrum in cdse quantum dots
Physical Review Letters, 1994Co-Authors: David J Norris, A Sacra, Christopher B Murray, Moungi G BawendiAbstract:We combine a new synthesis with transient optical hole burning to observe and assign the size evolution (19 to 115 A diameter, σ<5%) of a series of excited states in CdSe quantum dots. We observe an avoided crossing around the spin orbit energy in the hole spectra for ∼65 A dots, indicating the importance of valence band complexities in the description of the excited states. Comparsion with dc Stark data shows that bleach spectra are consistent with Localized Carrier induced electric fields.
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measurement of the size dependent hole spectrum in cdse quantum dots
Physical Review Letters, 1994Co-Authors: David J Norris, A Sacra, Christopher B Murray, Moungi G BawendiAbstract:We combine a new synthesis with transient optical hole burning to observe and assign the size evolution (19 to 115 \AA{} diameter, \ensuremath{\sigma}5%) of a series of excited states in CdSe quantum dots. We observe an avoided crossing around the spin orbit energy in the hole spectra for \ensuremath{\sim}65 \AA{} dots, indicating the importance of valence band complexities in the description of the excited states. Comparsion with dc Stark data shows that bleach spectra are consistent with Localized Carrier induced electric fields.
