Structural defects in InSb/AlxIn1−xSb quantum wells grown on GaAs (0 0 1) substrates

The effect of deformation potential scattering due to threading dislocations on electron mobilities has been investigated for InSb/AlxIn1−xSb quantum-well (QW) samples which were grown on GaAs (0 0 1) substrates with an InSb nucleation layer. Plan-view transmission electron microscopy images show that micro-twins cut through the InSb QW with a higher density in the View the MathML source directions than in the [1 1 0] direction. Partial dislocations which propagate along the micro-twins have accordingly an identical anisotropic density. However, theoretical calculations indicate that the dislocation-originated deformation potential scattering contributes negligibly to the measured mobilities at low temperatures.