Spinodal decomposition ranges of In$_x$ Ga$_{1 - x}$ N$_y$ P$_{1 - y}$ and GaAs$_x$ N$_y$ P$_{1 - x - y} $ alloys

Abstract

We have described spinodal decomposition ranges of GaP-rich $\mbox{GaAs}_x \mbox{N}_y \mbox{P}_{1 - x - y} $ and $\mbox{In}_x \mbox{Ga}_{1 - x} \mbox{N}_y \mbox{P}_{1 - y} $ alloy lattices matched to the GaP (001) substrate up to temperatures of 600$^{\circ}$C. Transformation of bonds, strain and coherency strain energies at the phase separation are taken into account. The alloys are considered to be strictly regular solutions. The strain energies of the alloys were calculated with the interaction parameters estimated by the valence force field model. It is shown that $\mbox{GaAs}_x \mbox{N}_y \mbox{P}_{1 - x - y} $, having one mixed sublattice, are more promising from the spinodal decomposition standpoint than $\mbox{In}_x \mbox{Ga}_{1 - x} \mbox{N}_y \mbox{P}_{1 - y} $, with two mixed sublattices.