Figure 2.

a 002 dark field (cross-section) transmission electron microscopy (TEM) images of two vertically aligned QD formed after depositing1.4 ML of InAs into a GaAs nanohole (QD1), the growth of 4-nm-thick GaAs barrier acting as tunneling layer and a final deposition of 0.9 ML of InAs (QD2). We observe that in this case, QD1 is larger in size than QD2. b TEM image of the formed structure when 1.2 ML of InAs is deposited to form the QD1 nanostructures. In this case, it can be observed that QD1 is now quite similar in size to QD2

Alonso-Gonz├ílez et al. Nanoscale Research Letters 2010 5:1913-1916   doi:10.1007/s11671-010-9771-2