Peculiarities of the energy spectrum of InSb/InAs/InGaAs/InAlAs/GaAs nanoheterostructures revealed by room temperature photomodulation FTIR spectroscopy

Fourier-transform infrared photoreflectance was used to optimize design and growth temperature of complex III-V nanoheterostructures proposed for efficient mid-IR emitters. They comprised an InAs/InGaAs quantum well (QW) with InSb sub-monolayer insertions and were grown by molecular beam epitaxy on GaAs substrates via a convex-graded InAlAs metamorphic buffer layer. The room temperature photoreflectance spectra supported by the full 8 × 8 Kane model calculations showed that the triple InSb insertions enhance the probability of the main optical transitions in the QW, while lowering the growth temperature results in a red shift of the transitions and further increase in their probability.