Si‐Ge‐Metal Ternary Phase Diagram Calculations

Abstract

Solution crystal growth and doping conditions of Si‐Ge alloys used for high‐temperature thermoelectric generation are determined here. Liquid‐phase epitaxy (LPE) has been successfully employed recently to obtain single‐crystalline homogeneous layers of Si‐Ge solid solutions from a liquid metal solvent. Knowledge of Si‐Ge‐metallic solvent ternary phase diagrams is essential for further single‐crystal growth development. Consequently, a thermodynamic equilibrium model was used to calculate the phase diagrams of the Si‐Ge‐M systems, including solid solubilities, where M is Al, Ga, In, Sn, Pb, Sb, or Bi. Good agreement between calculated liquidus and solidus data and experimental DTA and microprobe results was obtained. The results are used to compare the suitability of the different systems for crystal growth (by LPE‐type process).