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1

Hopping Excitons in GaInNAs - Simulation οf Micro- and Macrophotoluminescence Spectra

100%

Baranowski M., Latkowska M., Kudrawiec R., Misiewicz J.

Acta Physica Polonica A

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2011

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vol. 120

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issue 5

899-901

EN

Model of hopping excitons has been applied to explain the origin of sharp lines observed in microphotoluminescence spectra of GaInNAs layers. It has been shown that shape of the micro- and macrophotoluminescence spectra results from the exciton hopping between localizing centers and this phenomenon is responsible for the observation of sharp lines in microphotoluminescence experiment. In addition, the influence of different model parameters on photoluminescence spectra and their characteristic parameters such as the Stokes shift and full width at half maximum has been investigated.

2

Monte Carlo Simulations of the Influence of Localization Centres on Carrier Dynamics in GaInNAs Quantum Wells

88%

Baranowski M., Kudrawiec R., Latkowska M., Syperek M., Misiewicz J.

Acta Physica Polonica A

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2012

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vol. 122

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issue 6

1022-1025

EN

Model of hopping excitons is applied to study the carrier dynamics in GaInNAs/GaAs quantum well system. Impact of parameters describing localizing states (i.e., an average energy and density) on carrier dynamics in GaInNAs material is investigated theoretically. It is shown how those parameters affect the quantities that can be extracted from time resolved photoluminescence experiments. It is shown that obtained simulations can be very helpful in the interpretation of the experimental data.

3

Metastability of Band-Gap Energy in GaInNAs Compound Investigated by Photoreflectance

88%

Kudrawiec R., Misiewicz J., Pavelescu E., Konttinen J., Pessa M.

Acta Physica Polonica A

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2004

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vol. 106

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issue 2

249-263

EN

The band-gap energy of GaInNAs layers lattice-matched to GaAs substrate and annealed under different temperatures is investigated by photoreflectance spectroscopy. Different nitrogen nearest-neighbor environments of N atom appear in GaInNAs layers due to the post-growth annealing. It leads to an energy-fine structure of the band gap, i.e. well separated photoreflectance resonances related to different nitrogen nearest-neighbor environments (N-Ga_{4-m}In_m (0≤ m≤ 4) short-range-order clusters). The temperature dependence of the band gap E(T) related to different N-Ga_{4-m}In_m clusters is investigated in 10-280 K temperature range, and Varshni and Bose-Einstein parameters for E(T) are determined.

4

Near IR Refractive Index for GaInN Heavily Doped with Silicon

76%

Cywiński G., Kudrawiec R., Rzodkiewicz W., Kryśko M., Litwin-Staszewska E., Misiewicz J., Skierbiszewski C.

Acta Physica Polonica A

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2009

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vol. 116

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issue 5

936-938

EN

The authors report on growth and results of infrared measurements of GaInN heavily doped with silicon. The lattice matched to GaN epitaxial layer of Ga_{0.998}In_{0.002}N:Si has been grown in plasma assisted molecular beam epitaxy in the metal rich conditions. The room temperature Hall concentration and mobility of electrons are 2× 10^{20} cm^{-3} and 67 cm^{2}/(Vs), respectively. The refractive index has been determined by variable angle spectroscopic ellipsometry. The refractive index exhibited a significant reduction of its value (from 2.25 to 2 at 1.55 μm) at near IR range where are the main interests of potential applications for nitride based intersubband devices. Reported here values of refractive indices at 1.55 and 1.3 μm are appropriate for fabrication of cladding layers with the required contrast to GaN for intersubband devices. The observed drop of refractive index is attributed to the carrier-induced plasma edge effect, which has been directly observed in reflectance spectrum.

5

Fine Structure of the Localized Emission from GaInNAs Layers Studied by Micro-Photoluminescence

76%

Kudrawiec R., Latkowska M., Sęk G., Misiewicz J., Ibáñez J., Henini M., Hopkinson M.

Acta Physica Polonica A

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2009

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vol. 116

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issue 5

930-932

EN

GaInNAs bulk-like layers ( ≈ 20% In and ≈ 3% N) grown on GaAs substrate with various crystallographic orientations have been studied by micro-photoluminescence at low temperatures for a broad range of excitation conditions. In addition to photoluminescence peaks, which are associated with heavy- and light-hole free exciton recombination, a band of sharp lines was observed below the fundamental free exciton transition at low excitation. It shows that the localized emission which is typical of this alloy at low temperatures is composed of individual narrow photoluminescence lines which are associated with the recombination of single excitons. They can be localized on various local potential minima including those originating from the alloy content fluctuations and/or deep acceptor(donor)-like complexes.

6

Investigation of the Non-Square InGaAsP/InP Quantum Wells in the Electric Field by Photoreflectance

64%

Kudrawiec R., Sęk G., Rudno-Rudziński W., Misiewicz J., Wojcik J., Robinson B., Thompson D., Mascher P.

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issue 4-5

649-657

EN

Non-square quantum wells in electric field have been investigated by photoreflectance and photoluminescence spectroscopies. The structures have been obtained by a post-growth modification (rapid thermal annealing) of standard 1.55μm InGaAsP-based laser structures that were grown by gas source molecular beam epitaxy. During rapid thermal annealing a migration of semiconductor atoms across quantum well interfaces changes the quantum well profile from a square well to a rounded well. The modification of the profile changes energy levels in the quantum well and in consequence a blue shift of the quantum well emission peak is observed in photoluminescence. In this paper the blue shift of the ground state transition of post-growth modified quantum well structures has been investigated by both photoluminescence and photoreflectance techniques. Also a blue shift of excited state transitions has been observed in photoreflectance spectra. Generally, a stronger blue shift for the ground state transition than for excited state transitions has been observed. Additionally, oscillator strengths for all quantum well transitions have been determined from photoreflectance spectra. It has been found that the oscillator strength is constant for all quantum well transitions despite of modification of the quantum well profile.

7

Enhancement of Intersubband Absorption in GaInN/AlInN Quantum Wells

52%

Cywiński G., Skierbiszewski C., Siekacz M., Kryśko M., Feduniewicz-Żmuda A., Gladysiewicz M., Kudrawiec R., Misiewicz J., Nevou L., Kheirodin N., Julien F.

Acta Physica Polonica A

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2008

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vol. 114

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issue 5

1093-1099

EN

GaInN/AlInN multiple quantum wells were grown by RF plasma-assisted molecular beam epitaxy on (0001) GaN/sapphire substrates. The strain-engineering concept was applied to eliminate cracking effect and to improve optical parameters of intersubband structures grown on GaN substrates. The high quality intersubband structures were fabricated and investigated as an active region for applications in high-speed devices at telecommunication wavelengths. We observed the significant enhancement of intersubband absorption with an increase in the barrier thickness. We attribute this effect to the better localization of the second electron level in the quantum well. The strong absorption is very important on the way to intersubband devices designed for high-speed operation. The experimental results were compared with theoretical calculations which were performed within the electron effective mass approximation. A good agreement between experimental data and theoretical calculations was observed for the investigated samples.

Refine search results

Hopping Excitons in GaInNAs - Simulation οf Micro- and Macrophotoluminescence Spectra

Monte Carlo Simulations of the Influence of Localization Centres on Carrier Dynamics in GaInNAs Quantum Wells

Metastability of Band-Gap Energy in GaInNAs Compound Investigated by Photoreflectance

Near IR Refractive Index for GaInN Heavily Doped with Silicon

Fine Structure of the Localized Emission from GaInNAs Layers Studied by Micro-Photoluminescence

Investigation of the Non-Square InGaAsP/InP Quantum Wells in the Electric Field by Photoreflectance

Enhancement of Intersubband Absorption in GaInN/AlInN Quantum Wells