Isotherm Theoretical Study of the Al_xGa_1-xAs_ySb_1-y Quaternary Alloy Using the Regular Solution Approximation for Its...

This work presents the theoretical calculation of isotherm diagrams for quaternary alloys of III-V semiconductor compounds with the form III_xIII_1-xV_yV_1-y. In particular, the isotherm diagrams for the Al_xGa_1-xAs_ySb_1-y quaternary alloy at low temperatures were calculated (500 °C, 450 °C, 400 °C, and 350 °C). The Al_xGa_1-xAs_ySb_1-y quaternary alloy was formed from four binary compounds such as GaAs, AlAs, AlSb, and GaSb, all with direct bandgaps. The regular solution approximation was used to find the quaternary isotherm diagrams, represented in four linearly independent equations, which were solved using Parametric Technology Corporation Mathcad 14.0 software for different arsenic and antimony atomic fractions. The results support the possible growth of layers via liquid-phase epitaxy in a range of temperatures from 500 °C to 350 °C, where the crystalline quality could be improved at low temperatures. These semiconductor layers could have applications for optoelectronic devices in photonic communications, thermophotovoltaic systems, and microwave devices with good crystalline quality.