Low-temperature internal quantum efficiency of GaInN/GaN quantum wells under steady-state conditions

Abstract We compare the low-temperature photoluminescence (PL) intensities of a range of GaInN/GaN quantum well (QW) structures under identical excitation conditions, mounting the samples side by side. Normalizing the measured intensity to the absorbed power density in the QWs, we find that low-temperature PL efficiencies of several samples, which show close to 100% IQE in time-resolved PL, saturate at nearly an identical value. Of course, this is strong indicative of being 100% IQE at low temperature for those efficient samples. Using the low-temperature PL efficiency as a ``Reference'', on the other hand, we observe not only the effects of temperature-independent non-radiative losses on the low-temperature IQE, but also are able to determine the IQE of arbitrary samples on an absolute scale. Furthermore, we prove the experimental results by comparing the low-temperature efficiencies of a sample with an initial 100% IQE after intentionally introducing structural defects with argon-implantation.

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Enhancement of quantum efficiency in InGaN quantum wells by using superlattice interlayers and pulsed growth

Lithuanian Journal of Physics ◽

10.3952/physics.v55i4.3221 ◽

2016 ◽

Vol 55 (4) ◽

Author(s):

Kazimieras Nomeika ◽

Mantas Dmukauskas ◽

Ramūnas Aleksiejūnas ◽

Patrik Ščajev ◽

Saulius Miasojedovas ◽

...

Keyword(s):

Quantum Wells ◽

Quantum Efficiency ◽

Light Emitting Diode ◽

Internal Quantum Efficiency ◽

Recombination Coefficient ◽

Time Resolved ◽

Mocvd Growth ◽

Lower Strain ◽

Type Contact ◽

Ingan Quantum Wells

Enhancement of internal quantum efficiency (IQE) in InGaN quantum wells by insertion of a superlattice interlayer and applying the pulsed growth regime is investigated by a set of time-resolved optical techniques. A threefold IQE increase was achieved in the structure with the superlattice. It was ascribed to the net effect of decreased internal electrical field due to lower strain and altered carrier localization conditions. Pulsed MOCVD growth also resulted in twice higher IQE, presumably due to better control of defects in the structure. An LED (light emitting diode) structure with a top p-type contact GaN layer was manufactured by using both growth techniques with the peak IQE equal to that in the underlying quantum well structure. The linear recombination coefficient was found to gradually increase with excitation due to carrier delocalization, and the latter dependence was successfully used to fit the IQE droop.

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Low-temperature time-resolved photoluminescence in InGaN/GaN quantum wells

Semiconductors ◽

10.1134/1.1485662 ◽

2002 ◽

Vol 36 (6) ◽

pp. 641-646 ◽

Cited By ~ 2

Author(s):

A. V. Andrianov ◽

V. Yu. Nekrasov ◽

N. M. Shmidt ◽

E. E. Zavarin ◽

A. S. Usikov ◽

...

Keyword(s):

Low Temperature ◽

Quantum Wells ◽

Time Resolved ◽

Time Resolved Photoluminescence ◽

Temperature Time

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Unity quantum efficiency in III-nitride quantum wells at low temperature: Experimental verification by time-resolved photoluminescence

Applied Physics Letters ◽

10.1063/5.0055368 ◽

2021 ◽

Vol 119 (1) ◽

pp. 011106

Author(s):

Philipp Henning ◽

Shawutijiang Sidikejiang ◽

Philipp Horenburg ◽

Heiko Bremers ◽

Uwe Rossow ◽

...

Keyword(s):

Low Temperature ◽

Quantum Wells ◽

Quantum Efficiency ◽

Experimental Verification ◽

Time Resolved ◽

Time Resolved Photoluminescence

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Temperature Dependent and Time Resolved Optical Studies of Single Quantum Wells Produced by Interrupted Growth MBE

MRS Proceedings ◽

10.1557/proc-77-461 ◽

1986 ◽

Vol 77 ◽

Author(s):

B. S. Elman ◽

Emil S. Koteles ◽

C. Jagannath ◽

Y. J. Chen ◽

S. Charbonneau ◽

...

Keyword(s):

Low Temperature ◽

Quantum Wells ◽

Single Quantum ◽

Temperature Dependent ◽

Time Resolved ◽

Molecular Beam Epitaxial ◽

Decay Times ◽

Higher Temperature ◽

The Individual ◽

Molecular Beam Epitaxial Growth

ABSTRACTMultiple peaks, recently observed in the low temperature photoluminescence (PL) spectra of GaAs/AlGaAs single quantum wells fabricated by momentarily interrupting the molecular beam epitaxial growth between adjacent but different semiconductor layers, have been interpreted as originating within smooth regions in the quantum well layer differing in width by exactly one monolayer. We have observed similar structure in similarly grown samples but find that low temperature PL can be misleading. However, higher temperature PL or PL excitation spectroscopy do provide unambiguous evidence for the model of interface smoothing due to growth interruption. Further, time-resolved spectra yield decay times of the individual peaks which are consistent with this idea.

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Time-resolved photoluminescence studies of InGaN/GaN multiple quantum wells

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300001605 ◽

1997 ◽

Vol 2 ◽

Cited By ~ 10

Author(s):

J. Allègre ◽

P. Lefebvre ◽

S. Juillaguet ◽

W. Knap ◽

J. Camassel ◽

...

Keyword(s):

Low Temperature ◽

Quantum Wells ◽

Multiple Quantum Well ◽

Stimulated Emission ◽

Multiple Quantum ◽

Nitrogen Laser ◽

Energy Position ◽

Blue Band ◽

Time Resolved ◽

Decay Times

We report both cw and time resolved optical investigations performed on an InGaN/GaN multiple quantum well grown by MOVPE on <0001>-oriented sapphire substrate. At low temperature we find a strong “blue” luminescence band, of which energy position corresponds well with the wavelength of stimulated emission when excited with a nitrogen laser. We show that this PL band appears systematically red-shifted with respect to the QWs features, which supports a standard picture of fluctuations of the indium composition. Coming to the time-resolved data, we find at low temperature at least two “blue” band components which are both associated with long decay times (up to 4-5 ns at 8K). The decay time is temperature dependent and, when rising the temperature, the recombination rate increases. At room temperature, we reach typical values in the range ~100 to 500 ps.

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The promises and perfidy of cryomicroscopy and analysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016964x ◽

1994 ◽

Vol 52 ◽

pp. 382-383

Author(s):

Patrick Echlin

Keyword(s):

Low Temperature ◽

High Energy ◽

Short Paper ◽

List Type ◽

Time Resolved ◽

Energy Beam ◽

Cellular Analysis ◽

Dissolved Ions ◽

Embedding Medium ◽

Low Temperature Microscopy

The unusual title of this short paper and its accompanying tutorial is deliberate, because the intent is to investigate the effectiveness of low temperature microscopy and analysis as one of the more significant elements of the less interventionist procedures we can use to prepare, examine and analyse hydrated and organic materials in high energy beam instruments. The promises offered by all these procedures are well rehearsed and the litany of petitions and responses may be enunciated in the following mantra.Vitrified water can form the perfect embedding medium for bio-organic samples.Frozen samples provide an important, but not exclusive, milieu for the in situ sub-cellular analysis of the dissolved ions and electrolytes whose activities are central to living processes.The rapid conversion of liquids to solids provides a means of arresting dynamic processes and permits resolution of the time resolved interactions between water and suspended and dissolved materials.The low temperature environment necessary for cryomicroscopy and analysis, diminish, but alas do not prevent, the deleterious side effects of ionizing radiation.Sample contamination is virtually eliminated.

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Photophysical properties of N719 and Z907 dyes, benchmark sensitizers for dye-sensitized solar cells, at room and low temperature

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06629j ◽

2021 ◽

Vol 23 (10) ◽

pp. 6182-6189

Author(s):

Dariusz M. Niedzwiedzki

Keyword(s):

Solar Cells ◽

Low Temperature ◽

Optical Spectroscopy ◽

Room Temperature ◽

Photophysical Properties ◽

Dye Sensitized Solar Cells ◽

Time Resolved ◽

Dye Sensitized ◽

Sensitized Solar Cells

Photophysical properties of N719 and Z907, benchmark Ru-dyes used as sensitizers in dye-sensitized solar cells, were studied by static and time-resolved optical spectroscopy at room temperature and 160 K.

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