Optical properties of InAsSb nanostructures embedded in InGaAsSb strain reducing layer

This paper presents a comparative study on the optical properties of both type-I and type-II InAsSb/InGaAsSb nanostructures on InP substrates. A type-I band alignment is observed for InAsSb/InGaAsSb heterostructure when the Sb composition in InGaAsSb layers is 10%, while a type-II band alignment is observed for the InAsSb/InGaAsSb heterostructures when the Sb composition in InGaAsSb layers is higher than 10%. And, besides their long emission wavelength (around 2 μm), the InAsSb/In0.53Ga0.47As0.7Sb0.3 nanostructures with type-II band alignment have a much larger thermal activation energy (163 meV) compared with that of type-I band alignment (79 meV), which is helpful for suppressing the quenching of emission efficiency at high temperatures.

Research highlights
► A comparative study on the optical properties of both type-I and type-II InAsSb nanostructures.
► A type-I band alignment is observed for InAsSb/In0.53Ga0.47As0.9Sb0.1 heterostructure.
► A type-II band alignment is observed for the InAsSb/In0.53Ga0.47As1−xSbx (x=0.3, 0.5).
► The InAsSb/In0.53Ga0.47As0.7Sb0.3 has much larger thermal activation energy.