Liquid-Phase Synthesis and Properties of Constant Lattice Parameter AlGaInAsP Solid Solutions on Indium Phosphide Substrates

Abstract

Heterophase equilibria in the Al_xGa_yIn_{1– x– y}As_zP_{1 –z}/InP heterosystem have been analyzed in terms of a simple solution model in the temperature range 813–1023 K. We have assessed the stability limits of AlGaInAsP solid solutions synthesized on indium phosphide substrates and investigated kinetic features of the crystallization of constant lattice parameter AlGaInAsP solid solutions on InP substrates. The crystallization rate of AlGaInAsP solid solutions on InP substrates has been shown to depend on the synthesis temperature, the molten zone composition and length, and the temperature gradient. In addition, it has been shown to decrease with increasing aluminum concentration, independent of the molten zone length, owing to the decrease in the diffusion coefficient in the liquid phase. We have obtained composition dependences of component distribution coefficients in the Al_xGa_yIn_{1– x– y}As_zP_{1 –z} /InP heterosystem and shown that raising the synthesis temperature leads to a reduction in K_Al and K_P. The effect of synthesis conditions on the structural and luminescence properties of AlGaInAsP solid solutions on InP has been examined.