GaInAs/GaAs Waveguide Modulators With Multiple Short-Period Strained-Layer Superlattice Quantum Wells

1992 ◽  
Author(s):  
D. Yap ◽  
T.C. Hasenberg ◽  
T.Y. Hsu ◽  
S.L. Bourgholtzer ◽  
A.R. Kost ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Strained Layer ◽  
Short Period ◽  
Waveguide Modulators ◽  
Strained Layer Superlattice

Carrier lifetime measurements in short-period InAs/GaSb strained-layer superlattice structures

2009 ◽  
Vol 95 (21) ◽  
pp. 212104 ◽  
Author(s):  
Dmitry Donetsky ◽  
Stefan P. Svensson ◽  
Leonid E. Vorobjev ◽  
Gregory Belenky
Keyword(s):  
Carrier Lifetime ◽  
Lifetime Measurements ◽  
Strained Layer ◽  
Short Period ◽  
Strained Layer Superlattice ◽  
Superlattice Structures

Linear optical properties of quantum wells composed of all‐binary InAs/GaAs short‐period strained‐layer superlattices

1991 ◽  
Vol 58 (9) ◽  
pp. 937-939 ◽  
Author(s):  
T. C. Hasenberg ◽  
D. S. McCallum ◽  
X. R. Huang ◽  
Martin D. Dawson ◽  
Thomas F. Boggess ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Strained Layer ◽  
Short Period ◽  
Linear Optical Properties ◽  
Linear Optical ◽  
Strained Layer Superlattices

scholarly journals Interfacial Mixing Analysis for Strained Layer Superlattices by Atom Probe Tomography

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 437 ◽  
Author(s):  
Ayushi Rajeev ◽  
Weixin Chen ◽  
Jeremy Kirch ◽  
Susan Babcock ◽  
Thomas Kuech ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Cascade Laser ◽  
Atom Probe Tomography ◽  
Atom Probe ◽  
Strained Layer ◽  
Quantum Cascade ◽  
Spatially Resolved ◽  
Strained Layer Superlattice ◽  
Superlattice Structures ◽  
Laser Devices

Quantum wells and barriers with precise thicknesses and abrupt composition changes at their interfaces are critical for obtaining the desired emission wavelength from quantum cascade laser devices. High-resolution X-ray diffraction and transmission electron microscopy are commonly used to calibrate and characterize the layers’ thicknesses and compositions. A complementary technique, atom probe tomography, was employed here to obtain a direct measurement of the 3-dimensional spatially-resolved compositional profile in two InxGa1−xAs/InyAl1−yAs III-V strained-layer superlattice structures, both grown at 605 °C. Fitting the measured composition profiles to solutions to Fick’s Second Law yielded an average interdiffusion coefficient of 3.5 × 10−23 m2 s−1 at 605 °C. The extent of interdiffusion into each layer determined for these specific superlattices was 0.55 nm on average. The results suggest that quaternary active layers will form, rather than the intended ternary compounds, in structures with thicknesses and growth protocols that are typically designed for quantum cascade laser devices.

Structural Defects in InSb Quantum Wells Grown on GaAs (001) Substrates via Al0.09In0.91Sb/GaSb-AlSb Strained Layer Superlattice/AlSb/GaSb Buffer Layers

2005 ◽  
Vol 891 ◽  
Author(s):  
Tetsuya D. Mishima ◽  
Madhavie Edirisooriya ◽  
Michael B. Santos
Keyword(s):  
Quantum Wells ◽  
Buffer Layer ◽  
Defect Density ◽  
Buffer Layers ◽  
Structural Defects ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Plan View ◽  
Strained Layer ◽  
Strained Layer Superlattice

ABSTRACTStructural defects in InSb quantum well (QW) samples have been investigated by transmission electron microscopy (TEM). Using molecular beam epitaxy, an InSb QW with remotely-doped Al0.09In0.91Sb barriers was grown on a GaAs (001) substrate with buffer layers consisting of, in order from the substrate: 1 μm of GaSb, 1 μm of AlSb, 50 nm of GaSb-AlSb strained layer superlattice (SLS), and 3 μm of Al0.09In0.91Sb. Cross-sectional TEM analysis indicates that high densities of threading dislocations (TDs) are created at the two highly lattice-mismatched interfaces, the Al0.09In0.91Sb/GaSb-AlSb SLS and the GaSb/GaAs interfaces. Pairs of stereo images taken from plan-view TEM (PV-TEM) specimens show that TDs propagate through the InSb QW layer. The densities of TDs and micro-twin (MT) defects measured by PV-TEM are 9×108/cm2 and 4×103/cm, respectively. These values are worse than those in an InSb QW layer grown with a different buffer layer by a factor of ∼4. The different buffer layer contains an InSb interlayer that effectively filters out both TDs and MTs. Adopting an interlayer structure and reducing the GaSb and AlSb layer thickness may make it possible to fabricate a lower-defect-density yet thinner InSb QW sample with the type of buffer layer examined in this study.

The limits of strain and lattice parameter measurements by CBED

1989 ◽  
Vol 47 ◽  
pp. 518-519
Author(s):  
Hamish L. Fraser
Keyword(s):  
Electron Beam ◽  
Mirror Symmetry ◽  
Local Symmetry ◽  
Lattice Parameter ◽  
Growth Direction ◽  
Surface Relaxation ◽  
Strained Layer ◽  
Axis Parallel ◽  
Local Lattice ◽  
Strained Layer Superlattice

The topic of strain and lattice parameter measurements using CBED is discussed by reference to several examples. In this paper, only one of these examples is referenced because of the limitation of length. In this technique, scattering in the higher order Laue zones is used to determine local lattice parameters. Work (e.g. 1) has concentrated on a model strained-layer superlattice, namely Si/Gex-Si1-x. In bulk samples, the strain is expected to be tetragonal in nature with the unique axis parallel to [100], the growth direction. When CBED patterns are recorded from the alloy epi-layers, the symmetries exhibited by the patterns are not tetragonal, but are in fact distorted from this to lower symmetries. The spatial variation of the distortion close to a strained-layer interface has been assessed. This is most readily noted by consideration of Fig. 1(a-c), which show enlargements of CBED patterns for various locations and compositions of Ge. Thus, Fig. 1(a) was obtained with the electron beam positioned in the center of a 5Ge epilayer and the distortion is consistent with an orthorhombic distortion. When the beam is situated at about 150 nm from the interface, the same part of the CBED pattern is shown in Fig. 1(b); clearly, the symmetry exhibited by the mirror planes in Fig. 1 is broken. Finally, when the electron beam is positioned in the center of a 10Ge epilayer, the CBED pattern yields the result shown in Fig. 1(c). In this case, the break in the mirror symmetry is independent of distance form the heterointerface, as might be expected from the increase in the mismatch between 5 and 10%Ge, i.e. 0.2 to 0.4%, respectively. From computer simulation, Fig.2, the apparent monocline distortion corresponding to the 5Ge epilayer is quantified as a100 = 0.5443 nm, a010 = 0.5429 nm and a001 = 0.5440 nm (all ± 0.0001 nm), and α = β = 90°, γ = 89.96 ± 0.02°. These local symmetry changes are most likely due to surface relaxation phenomena.

Optical and structural characteristics of InGaAs/GaAs strained-layer superlattice

1998 ◽  
Author(s):  
Mei Li ◽  
Xueqian Li ◽  
Xiaowei Song ◽  
Zhongjiu Ge ◽  
Xingde Zhang
Keyword(s):  
Structural Characteristics ◽  
Strained Layer ◽  
Strained Layer Superlattice

Growth of a novel InAs‐GaAs strained layer superlattice on InP

1985 ◽  
Vol 46 (6) ◽  
pp. 569-571 ◽  
Author(s):  
M. C. Tamargo ◽  
R. Hull ◽  
L. H. Greene ◽  
J. R. Hayes ◽  
A. Y. Cho
Keyword(s):  
Strained Layer ◽  
Strained Layer Superlattice
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