Applied Physics Letters · 1988 · 163 citations · 13 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsElectronic MaterialsSemiconductor MaterialsDislocations In SemiconductorsQuantum WellsSemiconductor DefectsSemiconductor HeterostructuresSemiconductor PhysicsX-ray DiffractionCritical ThicknessPhotoluminescencePhotoluminescence In Quantum WellsQuantum Well StructuresStrain EffectsStrain RelaxationStrained Layer StructuresStrained Quantum Wells
The critical layer thickness for InxGa1−xAs layers in InxGa1−xAs/GaAs single strained quantum wells (SSQW’s) and strained-layer superlattices (SLS’s) are investigated. Photoluminescence microscopy (PLM) images and x-ray rocking curves for two series of SSQW and SLS structures corresponding to many different layer thicknesses were obtained. We find that the PLM technique, which directly images dislocations and is sensitive to low dislocation densities, is much more suitable for determining the onset of dislocation creation. The x-ray technique can detect lattice relaxation by dislocations but only at relatively high densities of dislocations. Using the former technique, we determine critical thicknesses of 190 Å for SSQW’s and 250 Å for SLS’s with x≊0.2. These results are near the theoretical predictions of J. W. Matthews, S. Mader, and T. B. Light [J. Appl. Phys. 41, 3800 (1970)] (150 and 300 Å, respectively) and are much lower than results obtained by x-ray or other techniques which sense lattice relaxation.
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Dislocations in the diamond lattice
J. Hornstra · Journal of Physics and Chemistry of Solids · 1958 · 521 citations
T. G. Andersson, Z. G. Chen, V. D. Kulakovskiĭ et al. · Applied Physics Letters · 1987 · 247 citations