Strain engineering of self-organized InAs quantum dots - art. no. 085305

The effects of a thin gallium-rich InxGa1-xAs cap layer on the electronic p roperties of self-organized InAs quantum dots (QD's) are investigated both experimentally and theoretically. Increasing the indium concentration of th e cap layer allows tuning the ground state transition to lower energies mai ntaining strong quantization of the electronic states. Strain-driven partia l decomposition of the InxGa1-xAs cap layer increases the effective QD size during growth and the altered barrier composition leads to a partial strai n relaxation within the capped InAs QD's. Strain engineering the structural properties of the QD's as well as the actual confining potential offers a pathway to control the electronic properties, e.g., to shift the emission w avelength of lasers based on self-organized InAs QD's to the infrared.