Defect passivation in strain engineered InAs/(InGa)As quantum dots

A series of InAs quantum dots (QDs) embedded in InxGa1 - xAs confining layers with different In composition and thickness have been investigated by photoluminescence. An enhancement of the PL signal up to 25 times was obtained via hydrogen irradiation. It has been shown that two different non radiative channels account for the temperature dependence of the PL spectra in both as-grown and hydrogenated samples. In the latter samples, only a partial passivation of both type of defects, whose nature is discussed, has been achieved.