Low Pressure OMVPE Grown Compressive Strained Ingaas QWS Surrounded by Tensile Strained Ingaas Spacers

1996 ◽  
Vol 441 ◽  
Author(s):  
O. A. Laboutine ◽  
A. G. Choo ◽  
S. H. Kim ◽  
N. H. Kim ◽  
H. S. Park ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Line Width ◽  
Deposition Temperature ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Strained Layers ◽  
X Ray ◽  
Barrier Layers ◽  
Ga Content

AbstractThe photoluminescence (PL) measurement of unstrained and compressive strained InxGa1−xAs quantum wells (QWs) demonstrated that the interfaces had a roughness of 1 to 2.5 monolayers (ML). The spacer layers of tensile strained InyGa1−yAs were inserted between a compressive strained In0.7Ga0.3As QW and the InP barrier layers. PL spectra of the In0.7Ga0.3As/InyGa1−yAs/InP structures grown at 605°C became significantly narrower with increasing Ga content in the spacer layers above (1−y)=0.6. The PL line width of the In0.7Ga0.3As/In0.3Ga0.7As alternatingly strained multiple quantum well (MQW) structures gradually decreased when the number of periods and the deposition temperature increased. The structure, consisting of 4 periods grown at 635°C, exhibited a PL line width of about 4 meV which corresponded to the QW thickness fluctuation of 0.5 ML. The superlattice satellites of X-ray rocking curves of MQW structures were better defined under an envelope corresponding to the tensile strained layers.

Use of Valved, Solid Group V Sources for the Growth of GaAs/GaInP Heterostructures by Molecular Beam Epitaxy

1992 ◽  
Vol 281 ◽  
Author(s):  
F. G. Johnson ◽  
G. W. Wicks ◽  
R. E. Viturro ◽  
R. Laforce
Keyword(s):  
Molecular Beam Epitaxy ◽  
Quantum Well ◽  
Quantum Wells ◽  
Molecular Beam ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Misfit Dislocations ◽  
Group V ◽  
X Ray

ABSTRACTWe report on the first growth of GaAs/Ga0.5In0.5P heterostructures by conventional molecular beam epitaxy using solid-source valved crackers to supply both the arsenic and the phosphorus fluxes. By regulating the group V fluxes with the cracker needle valves, arsenide-phosphide heterostructures were successfully grown with virtually no group V intermixing between layers. For comparison, similar heterostructure samples were grown using only the mechanical shutters to switch between group V fluxes, and the resulting layers were severely intermixed. The amount of group V intermixing was shown to be independent of whether As2 or As4 fluxes were used to grow the layers. A GaAs/Ga0.5In0.5P multiple quantum well sample was also grown using the valved crackers. Photoluminescence peaks were clearly observed from 40 Å, 80 Å, and 300 Å GaAs quantum wells, but no luminescence was detected from a 20 Å well. An 80Å GaAs/ 80Å Ga0.5In0.5P superlattice was grown, and superlattice satellite peaks were observed in the X-ray rocking curves. The appearance of misfit dislocations suggests localized intermixing at the interfaces.

X-ray Rocking Curve Analysis of Strained Heterointerfaces and Quantum Wells

1994 ◽  
Vol 38 ◽  
pp. 165-174
Author(s):  
C. R. Wie
Keyword(s):  
Experimental Data ◽  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Effect ◽  
Multiple Quantum Well ◽  
Curve Analysis ◽  
Multiple Quantum ◽  
Rocking Curve ◽  
X Ray ◽  
Strained Quantum Wells

Abstract A detailed discussion is given for the x-ray rocking curve analysis of semiconductor heterointerfaces and strained quantum wells using x-ray interferometry. It is shown that for a single heteroepitaxiai layer sample and a multiple quantum well sample, the heterointerface where the composition changes in both anion and cation sublattices can be studied with a half monolayer sensitivity by analyzing the x-ray rocking curve profile. Such sample systems include GaInAs/InR InAs/GaSb, GalnP/GaAs, ZnSe/GaAs, etc. A simple kinematical diffraction principle involved in the x-ray analysis is explained. Namely, the relative phase difference between the reflection amplitudes of any two layers depends on the total sum of strain (or mismatch)-thickness products over the intervening layers and interfaces. The x-ray interferometry is also effective in measuring the strain-thickness product of strained quantum wells. Experimental data and analysis results are presented for a series of functional device structures having a strained quantum well. For a more complicated sampie structure which involves both a (strained) quantum-effect layer and strained interfaces, it is shown that the x-ray interferometry is only capable of providing the total strain-thickness product over the quantum layer and the surrounding interfaces, but no detailed information about the interface grading can be gained from the rocking curve analysis alone if onhy one isolated sample is measured. An experimental data of such a sample, 0.3μm-GaAs/100Å-GaInP/ GaAs(001), is analyzed.

Laser-Modified Chemical Beam Epitaxy of InGaAs/GaAs Multiple Quantum Wells Using Tris-Dimethylaminoarsenic

1994 ◽  
Vol 354 ◽  
Author(s):  
H.K. Dong ◽  
N.Y. Li ◽  
C.W. Tu
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Laser Irradiation ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Chemical Beam Epitaxy ◽  
Quantum Well Structures ◽  
X Ray ◽  
Strained Quantum Well ◽  
First Time

AbstractWe report for the first time laser-modified chemical beam epitaxy (CBE) of InGaAs/GaAs multiple quantum well (MQW) structures using trimethylindium (TMIn), triethylgallium (TEGa), and tris-dimethylaminoarsenic (TDMAAs), a safer alternative to arsine. X-ray rocking curve (XRC) and low-temperature photoluminescence (PL) measurements were used to characterize the pseudomorphic strained quantum well structures. As determined by the X-ray simulation, laser irradiation during the InGaAs well growth was found to enhance the InGaAs growth rate and reduce the indium concentration in the substrate temperature range studied, 440-S00°C, where good interfaces can be achieved. We attribute these changes to laser-enhanced decomposition of TEGa and laser-enhanced desorption of TDMAAs. With laser irradiation, lateral variation of PL exciton peaks was observed, and the PL peaks became narrower.

Growth and Characterization Of GexSi1−x/ Si Multiple Quantum Well Structures

1992 ◽  
Vol 263 ◽  
Author(s):  
D.W. Greve ◽  
R. Misra ◽  
M.A. Capano ◽  
T.E. Schlesinger
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Small Variation ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
High Quality ◽  
Quantum Well Structures ◽  
X Ray

ABSTRACTWe report on the growth and characterization of multiple quantum well structures by UHV/ CVD epitaxy. X- ray diffraction is used to verify the expected layer periodicity and to determine the quantum well thickness. Photoluminescence measurements show peaks which we associate with recombination of excitons in the quantum wells. The measurements are consistent with high quality layers with small variation in quantum well thickness across a wafer.

scholarly journals Photo- and cathodoluminescence investigations of piezoelectric GaN/AlGaN quantum wells

2000 ◽  
Vol 639 ◽  
Author(s):  
E.M. Goldys ◽  
M. Godlewski ◽  
M.R. Phillips ◽  
A.A. Toropov
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Electric Fields ◽  
Free Exciton ◽  
Multiple Quantum Well ◽  
Depth Profiling ◽  
Multiple Quantum ◽  
Recombination Mechanism ◽  
Decay Times ◽  
Piezoelectric Fields

ABSTRACTWe have examined multiple quantum well AlGaN/GaN structures with several quantum wells of varying widths. The structures had strain-free quantum wells and strained barriers. Strong piezoelectric fields in these structures led to a large red shift of the PL emission energies and long decay times were also observed. While the peak energies could be modelled using the effective mass approximation, the calculated free exciton radiative lifetimes were much shorter than those observed in experiments, indicating an alternative recombination mechanism, tentatively attributed to localised excitons. Cathodoluminescence depth profiling revealed an unusually small penetration range of electrons suggesting that electron-hole pairs preferentially remain within the multiple quantum well region due to the existing electric fields. Spatial fluctuations of the cathodoluminescence intensity were also observed.

scholarly journals Disordering of InGaN/GaN Superlattices After High-Pressure Annealing

1998 ◽  
Vol 537 ◽  
Author(s):  
M.D. McCluskey ◽  
L.T. Romano ◽  
B.S. Krusor ◽  
D. Hofstetter ◽  
D.P. Bour ◽  
...  
Keyword(s):  
Quantum Well ◽  
Secondary Ion Mass Spectrometry ◽  
Multiple Quantum Well ◽  
Blue Shift ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Composition Profiles ◽  
Secondary Ion

AbstractInterdiffusion of In and Ga is observed in InGaN multiple-quantum-well superlattices for annealing temperatures of 1250 to 1400°C. Hydrostatic pressures of up to 15 kbar were applied during the annealing treatments to prevent decomposition of the InGaN and GaN. In as-grown material, x-ray diffraction spectra show InGaN superlattice peaks up to the fourth order. After annealing at 1400°C for 15 min, only the zero-order InGaN peak is observed, a result of compositional disordering of the superlattice. Composition profiles from secondary ion mass spectrometry indicate significant diffusion of Mg from the p-type GaN layer into the quantum well region. This Mg diffusion may lead to an enhancement of superlattice disordering. For annealing temperatures between 1250 and 1300°C, a blue shift of the InGaN spontaneous emission peak is observed, consistent with interdiffusion of In and Ga in the quantum-well region.

PHOTOCONDUCTIVITY, PHOTOREFLECTANCE AND PHOTOLUMINESCENCE OF GaAs-AlAs MULTIPLE QUANTUM WELLS

1985 ◽  
Vol 56 ◽  
Author(s):  
H. NEFF ◽  
K. J. BACHMANN ◽  
W. D. LAIDIG
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Heavy Hole ◽  
Multiple Quantum Well ◽  
Light Hole ◽  
Multiple Quantum ◽  
Indirect Transition ◽  
Temperature Dependent ◽  
Direct Inter ◽  
Phonon Absorption

AbstractEmploying temperature dependent photoconductivity, photoluminescence and photoreflectivity measurements, we have analyzed a GaAs-AlAs multiple quantum well. The above optical techniques clearly resolve the fundamental inter-subband transitions, including heavy hole-light hole splittings. At T < 60K an anomalously high photoconductivity was discovered below the direct inter-subband transitions and is attributed tentatively to the presence of extrinsic interface states within the bandgap. For T > l00K the fundamental indirect transition was discovered and associated with LO (L) - phonon absorption.

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