Effect of biaxial strain on exciton transitions of AlxGa1−xAs epitaxial layers on (001) GaAs substrates

Abstract
From the analysis of spectroscopic ellipsometry measurements in the temperature range between 16 and 300 K, the exciton splittings and shifts due to lattice mismatch in the AlxGa1−xAs/GaAs alloy system grown by liquid‐phase epitaxy are obtained. The temperature dependence of the Ev10 and Ev20 exciton transitions shows that the difference in the expansion coefficients of the two materials does not play a significant role in the induced internal stress. The internal stresses are evaluated from an x‐ray double‐crystal diffraction technique. The shear deformation potential values of AlxGa1−xAs determined from the experimental results are in disagreement with those found in the literature.