Electronic structure of InAs quantum dots with GaAsSb strain reducing   layer: Localization of holes and its effect on the optical properties
  The electronic structure of InAs quantum dots covered with the GaAs(1-y)Sb(y) strain reducing layer has been studied using the k.p theory. We explain previous experimental observations of the red shift of the photoluminescence emission with increasing y and its blue shift with increasing excitation power. For y>0.19 type-II dots are formed with holes localized in the GaAsSb close to the dot base; two segments at opposite sides of the dot, forming molecular-like states, result from the piezoelectric field. We also propose an experiment that could be used to identify the hole localization using a vertical electric field. 
P. Klenovsk\'y, V. K\v{r}\'apek, D. Munzar, J. Huml\'i\v{c}ek
cond-mat.mes-hall