Phase equilibria in the system Al–Ga–As–Sn and electrical properties of Sn-doped liquid phase epitaxial AlxGa1−xAs

Abstract

Experimental and calculated phase data for the Al–Ga–As–Sn system are presented. A ``simple solution'' treatment adequately predicts the quaternary from data available from the bounding binary and ternary systems. The distribution coefficient for Al between the solid and liquid increases with increasing Sn concentration in the liquid. For constant Sn concentration in the growth solution, the net electron concentration in solution‐grown Al x Ga1−x As decreases with increasing x, particularly near the direct‐indirect crossover composition. This occurs primarily because of the deepening of the donor level from ∼ 6 meV in GaAs to at least 66 meV in the indirect gap composition region of Al x Ga1−x As.