Stability in peak emission wavelength in strain-coupled multilayer InAs/GaAs quantum dot heterostructures when subjected to high-temperature rapid thermal annealing

In quantum dot laser and solar cell structures, high temperature is required for the growth of cladding or window layer. Therefore to check the thermal stability in emission peak in high temperature strain coupled InAs/GaAs QDs are grown by MBE capped with two different type of spacer layer- InGaAs and InAlGaAs. Photoluminescence spectra shows multimodal distribution of QDs. Till 700 o C annealing temperature, no shift in peak emission wavelength is observed for InGaAs capped sample. The vertical strain prevents the inter-diffusion by maintaining a strain relaxed state due to coupling. For quaternary InAlGaAs capped QDs this stability is observed till 800 o C.