We have investigated the shape and composition profiles of buried and surface InAsGaAs Stranski-Krastanov quantum dots (QDs) by using the spectrum-imaging (SI) method with energy-filtered transmission electron microscopy (EFTEM). Indium maps from EFTEM SI reveal lens and truncated pyramid shapes for the surface and buried QDs, with an increase in composition variations for the buried QDs. Photoluminescence measurements reveal an emission at 1.075 eV, associated with confined states in the buried QDs, along with a high energy shoulder, associated with band-tail states due to In-Ga intermixing in the vicinity of the buried QDs.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)