Bulk crystal growth of antimonide based III-V compounds for TPV applications

In this paper, the bulk growth of crack-free GaInSb and single phase GaInAsSb alloys are presented. A new class of III-V quasi-binary semiconductor alloys [A(III)B(V)](1-x)[CIIIDV](x) has been synthesized and bulk crystals grown from the melt for the first time. The present investigation is focused on the quasi-binary alloy (GaSb)(1-x)(InAs)(x) (0<x<0.05) due to its importance for thermophotovoltaic applications. The structural properties of this melt-grown quasi-binary alloy are found to be significantly different from the conventional quaternary compound Ga1-xInxAsySb1-y with composition x = y. Synthesis and growth procedures are discussed. For the growth of ternary alloys, it was demonstrated that forced convection or mixing in the melt during directional solidification of InxGa1-xSb (0<x<0.1) significantly reduces cracks in the crystals.