Molecular beam epitaxial growth and luminescence of InxGa1−xAs/InxAl1−xAs multiquantum wells on GaAs

Abstract

This letter reports the successful molecular beam epitaxial growth of high-quality InxGa1−xAs/InxAl1−xAs directly on GaAs. In situ observation of dynamic high-energy electron diffraction oscillations during growth of InxGa1−xAs on GaAs indicates that the average cation migration rates are reduced due to the surface strain. By raising the growth temperature to enhance the migration rate and by using misoriented epitaxy to limit the propagation of threading and screw dislocations, we have grown device-quality In0.15Ga0.85As/In0.15Al0.85As multiquantum wells on GaAs with a 0.5–1.0 μm In0.15Ga0.85As buffer layer. The luminescence efficiency of the bound exciton peak increases with misorientation and its linewidth varies from 11 to 15 meV.