Figure 13

Empty state cross-section scanning tunneling microscopy image of the SML QD insertion taken at low positive sample bias. Ten cycles of 0.5 ML InAs deposition cycles separated by 2.2 ML GaAs spacers at a substrate temperature of 490 °C has been deposited. 2–3 nm-wide In-rich columns tilted by ∼35^o with respect to [001] direction are observed