InAs/InP Quantum Dots in Etched Pits by Droplet Epitaxy in Metalorganic Vapor Phase Epitaxy

The growth of InAs quantum dots (QDs) on InP(100) via droplet epitaxy in a metalorganic vapor phase epitaxy (MOVPE) reactor is studied. Formation of indium droplets is investigated with varying substrate temperature, and spontaneous formation of nanoholes is observed for the first time under MOVPE conditions. Indium droplets are crystallized into QDs under arsenic flow at different temperatures. For temperatures greater than 500 degrees C, a local etching takes place in the QD vicinity, showing an unexpected morphology which is found to be strongly dependent on the crystallization conditions. Such QDs are structurally and optically investigated and emission from single QDs in the telecom C-band is detected via microphotoluminescence at low temperature.