Molecular beam epitaxy of A$^{\mathrm{III}}$P$_x$As$_{1-x}$ solid solutions: Mechanism of composition formation in the sublattice of a group V element

The effect of substrate temperature, As$_2$ and P$_2$ molecular flux densities, and growth rate on the composition of (A$^{\mathrm{III}}$)P$_x$As$_{1-x}$ solid solution layers prepared by molecular beam epitaxy is experimentally investigated. Experimental data in a wide range of growth conditions are analyzed. The results obtained are presented in the form of a kinetic model for describing the process of formation of the composition in the Group V sublattice of the (A$^{\mathrm{III}}$)P$_x$As$_{1-x}$ solid solution upon molecular beam epitaxy. The model can be used for choosing the growth conditions of the (A$^{\mathrm{III}}$)P$_x$As$_{1-x}$ (001) solid-solution layers of a specified composition.