Figure 3.

Photoluminescence spectra of the three different vertical QD pairs studied in this work. Black, red, and blue lines correspond to samples in which the QD1 nanostructure layer is formed by depositing 1.2, 1.4, and 1.5 MLof InAs, respectively. The arrows in the figure point out the two families of QD formed in each sample

Alonso-González et al. Nanoscale Research Letters 2010 5:1913   doi:10.1007/s11671-010-9771-2