A Stranski-Krastanov to Volmer-Weber transition in the growth mode of self-assembled quantum dots

We present recent experiments for tensile -strained Ge QDs on InAlAs(111)A where we observe that growth proceeds via the Stranski-Krastanov (SK) growth mode at lower temperatures and transitions to the Volmer- Weber (VW) growth mode at higher temperatures. We discuss atomistic kinetic Monte Carlo simulations that show how the SK to VW growth mode transition is affected by model parameters. We find that systems are more likely to transition from a SK to a VW mode when the bond energy between substrate atoms is weaker than the bond energy between atoms of the deposited material. We also show how entropic effects due to intermixing can stabilize a layer -by -layer growth mode in certain parameter regimes.