Enhanced room-temperature 3.5 µm photoluminescence in stress-balanced metamorphic In(Sb,As)/In(Ga,Al)As/GaAs quantum wells

Abstract

In this Letter, we report on the design optimization of metamorphic InSb/InAs/In(Ga,Al)As/GaAs heterostructures with type-II-in-type-I quantum well (QW) active regions, aimed at the enhancement of their room-temperature photoluminescence (PL). The strong influence of the design of the convex-graded metamorphic buffer layer (MBL) and the value of the MBL inverse step in the range from 2 to 14 mol % In on stresses in such heterostructures, as well as their PL intensity, are discussed. The optimized metamorphic In(Sb,As)/In0.63Ga0.37As/In0.75Al0.25As/MBL/GaAs structure with the inverse step of 10 mol % demonstrates 3.2–3.5 µm mid-IR PL intensity quenching from liquid-nitrogen to room temperature by a factor of 12.