Miscibility Calculation of GaN1-xPx Ternary Alloys

A theoretical calculation of the miscibility gap with considering the mismatch strain and elastic parameters was performed for the GaN1-xPx ternary alloys on (0001) GaN/sapphire substrates based on the strictly regular solution model. The calculated results show that the boundary of the spinodal isotherm shifts from x=0.06 to x=0.25 at the growth temperature of 1200 K as the strain factor increases from 0 to 1, indicating that the strain in the GaN1-xPx layers can suppress the phase separation. Meanwhile, with the increase of the effective elastic parameters of GaN and GaP, the available maximum P content also increases slightly at the growing temperature.