Dependence of the properties of GaAs (111)A and Ga1-xAlxAs (111)A epitaxial layers on the conditions of their growth by organometallic vapor phase epitaxy

The studies of GaAs (111)A and Ga1-xAlxAs (111)A epitaxial layers have been carried out using low-temperature photoluminescence and high-resolution X-ray diffraction. Correlation between the B-V/A(III) ratio and the photoluminescence intensity of n-GaAs:Si layers prepared through OMVPE on a semi-insulating GaAs (111)A substrate is discussed in details. For an epitaxial layer prepared at the B-V/A(III) ratio of 94, the peak characteristic of a free exciton was found to be separated from a continuous broad edge band and higher carrier mobility was revealed. High-resolution X-ray diffraction measurements of a two layer epitaxial n-GaAs:Si/p-Ga1-xAlxAs:Zn heterostructure prepared on a p-GaAs (111)A substrate indicates crystallization of structurally perfect epitaxial heterostructures with a mirror-like surface morphology.