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Hitzel, F.; Klewer, G.; Lahmann, S.; Rossów, U.; Hangleiter, A.

doi:10.1103/physrevb.72.081309

Cited by 40 publications

(28 citation statements)

References 12 publications

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“…5 In photoluminescence experiments with a macroscopic excitation spot of 8 ϫ 10 −5 cm 2 on similar or identical samples, these high energy emissions appear as a broad emission line averaged over the spot size. To clearly identify the V-shaped pit quantum wells as the origin of the broad high energy photoluminescence emission independently of the SNOM measurements, we have excluded step by step alternative possibilities and unambiguously identified the high energy emission's origin from the V-shaped pit quantum wells.…”

Section: Emission From V-shaped Pit Facet Quantum Wellsmentioning

confidence: 96%

“…The GaInN quantum wells on the V-shaped pit's facets are narrower than the c-plane quantum wells and act as potential barriers. 5,6 Both mechanisms may keep the charge carriers effectively away from the threading dislocations, which are known as nonradiative recombination centers. 7 Even a reduction of the density of threading dislocations will not lead to a remarkable increase in the efficiency of light emitting diodes ͑LEDs͒.…”

Section: Introductionmentioning

confidence: 99%

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Emission and recombination characteristics ofGa1−xInxN∕GaNquantum w

et al. 2007

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We demonstrate quantitatively that the realization of high internal quantum efficiency of more than 70% at room temperature in GaInN / GaN quantum well structures is possible with potential barriers, which are caused by V-shaped pit formation around threading dislocations. Localization of charge carriers is present in the samples, but its contribution to room temperature quantum efficiency is negligible. The emission and recombination characteristics of GaInN / GaN quantum well structures with deep V-shaped pits are studied in detail. Due to narrower wells and smaller piezoelectric fields, the GaInN quantum wells on the facets of extended V-shaped pits emit several hundred meV higher in energy than the c-plane quantum wells. Because of the simultaneous growth, the emission energies of the c-plane and the V-shaped pit quantum wells are correlated. The relative intensity of both emissions depends on the ratio between the c-plane and the V-shaped pit surface area during GaInN quantum well growth. GaInN / GaN LED structures from different commercial sources feature V-shaped pits and their effects on the emission characteristics, too. Hence, a universal relevance of V-shaped pit potential barriers around dislocations in GaInN / GaN heterostructures for high internal quantum efficiency is suggested.

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Section: Emission From V-shaped Pit Facet Quantum Wellsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Emission and recombination characteristics ofGa1−xInxN∕GaNquantum w

et al. 2007

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“…8 In this context, correlating morphology with temporally and spatially resolved luminescence signals is essential in the understanding of luminescence properties of InGaN based quantum wells ͑QWs͒. [9][10][11] Cathodoluminescence ͑CL͒ techniques have proven to be very useful for studying various GaN based nanostructures. 12,13 However, to get a complete picture of carrier recombination and diffusion processes, one needs a spectroscopic tool which yields high spatial and temporal resolutions at the same time.…”

mentioning

confidence: 99%

High spatial resolution picosecond cathodoluminescence of InGaN quantum wells

Sonderegger

Feltin

Merano

et al. 2006

Applied Physics Letters

103

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The authors have studied In x Ga 1−x N / GaN ͑x Ϸ 15% ͒ quantum wells ͑QWs͒ using atomic force microscopy ͑AFM͒ and picosecond time resolved cathodoluminescence ͑pTRCL͒ measurements. They observed a contrast inversion between monochromatic CL maps corresponding to the high energy side ͑3.13 eV͒ and the low energy side ͑3.07 eV͒ of the QW luminescence peak. In perfect correlation with CL images, AFM images clearly show regions where the QW thickness almost decreases to zero. Pronounced spectral diffusion from high energy thinner regions to low energy thicker regions is observed in pTRCL, providing a possible explanation for the hindering of nonradiative recombination at dislocations.

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“…Therefore, one of the important questions is whether GaInN layers are intrinsically inhomogeneous or whether defects are inducing local variations of the bandgap. The latter has already been demonstrated for the "antilocalisation" mechanism [2,[5][6][7]. To clarify the influence of dislocations on the efficiency of green-emitting GaInN/GaN structures, it is necessary to investigate the spatial structure of the luminescence of such structures on a sub micrometer length scale.…”

mentioning

confidence: 96%

Scanning near‐field luminescence microscopy of green light emitting GaInN/GaN quantum wells grown on c‐plane sapphire and on c‐plane bulk GaN

Clodius

Jönen

Bremers

et al. 2011

Phys. Status Solidi C

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In contrast to blue and violet emitting GaInN quantum well structures grown on sapphire, which show a high internal quantum efficiency (IQE), green emitting structures suffer from relatively low efficiencies. Usually, the large internal polarization fields are made responsible for such reduced efficiencies. For quantum wells with high In content, however, the efficiencies are even lower than expected.In this work we present the results of our near‐field optical investigations of the photoluminescence of green emitting GaInN quantum well structures grown on c‐plane sapphire and on bulk GaN substrates. Our aim is to clarify the influence of defects on the spatial structure of the luminescence of green emitting quantum wells. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Localized high-energy emissions from the vicinity of defects in high-efficiencyGaxIn1−xN∕GaN

Cited by 40 publications

References 12 publications

Emission and recombination characteristics ofGa1−xInxN∕GaNquantum w

Emission and recombination characteristics ofGa1−xInxN∕GaNquantum w

High spatial resolution picosecond cathodoluminescence of InGaN quantum wells

Scanning near‐field luminescence microscopy of green light emitting GaInN/GaN quantum wells grown on c‐plane sapphire and on c‐plane bulk GaN

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