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 GaAs1-ySby strain reducing layer has been studied using the (k) over right arrow . (p) over right arrow 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 the 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. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3517446]