Dependence of quantum-dot formation on substrate orientation studied by magnetophotoluminescence

We have investigated the substrate orientation-dependence of InAs/GaAs quantum dot growth by photoluminescence spectroscopy in very high magnetic fields. An abrupt change from one-dimensional to three-dimensional charge confinement is observed for InAs deposited on (100) GaAs. On the tilted (311)B substrates, the quantum dot morphology is different, resulting in a weaker charge confinement that gradually increases with the amount of deposited InAs. At 1.9 monolayers, the quantum-dot confinement on this substrate orientation is as effective as for the (100) oriented substrates. By studying the confinement of the charges in samples with quantum dots at different stages of development, we are able to give insight into the quantum-dot formation process