Scalable InAs/InGaAs DWELL structures for broadband infrared emission spanning the E- to O-band.

This study presents the optimization of MOCVD growth conditions for InAs/InGaAs quantum dots-in-a-well (DWELL) structures on 4-inch GaAs substrates incorporating an InGaP seed layer. By precisely tuning the arsenic-to-indium (As/In) ratio, growth temperature, and deposition duration, we achieved accurate control over the size and density of quantum dots (QDs), enabling a broad tuning of infrared emission wavelengths from 1200 to 1450 nm. Using photoluminescence spectroscopy and numerical modeling, we investigated the impact of In content of the InₓGa1-ₓAs strain-reducing cap layers on the optical properties of the DWELL structures. A linear correlation was observed between In concentration and the emission peak wavelength, highlighting the significant role of the capping layer composition in tuning QD emission characteristics. This work highlights the critical importance of growth parameter optimization in engineering QD-based heterostructures paving the way for their integration into advanced optoelectronic and quantum technology applications.