Controlled quantum confinement potentials in self-formed InGaAs quantum dots grown by atomic layer epitaxy technique

The present work deals with the control of quantum confinement potential in self-formed In0.5Ga0.5As/GaAs quantum dots. The dots were grown by alternate supply of (InAs)/(GaAs) precursors using atomic layer epitaxy technique, As the number of supply cycles increased from 9 to 30, dot size observed by transmission electron microscopy increased from 20 to 32 nm in diameter and photoluminescence (PL) spectra shifted to lower energy. Measuring PL spectra under a magnetic field, we found that the smaller the dots, the smaller the diamagnetic shifts. These results indicate that the quantum confinement potential was controlled in our growth technique.