Growth of InAsSb/InPSb heterojunctions for mid-IR detector applications

InAsSb/InPSb heterojunctions and InAsSb homojunctions were grown by metalorganic vapor phase epitaxy (MOVPE) on GaSb for potential mid-infrared photodetector applications. Despite the presence of a large miscibility gap for both InAsSb and InPSb alloys, we have grown excellent structural quality epilayers at a growth temperature of 500 °C using all-alkyl precursors. Hall effect measurements of p-type InAsSb are complicated by the presence of an n-type accumulation layer at the surface. Mesa diode structures were fabricated by wet chemical etching and optical lithography. Heterojunction devices were shown to have higher R0A values than homojunction devices at room temperature.