Self-assembled epitaxial growth of quantum dots via molecular beam epitaxy
Abstract
We have grown indium arsenide quantum dots via molecular beam epitaxy in the Stranski-Krastanov mode. In situ RHEED characterization was used to observe the formation of the self-assembled quantum dots, which were grown at substrate temperature of 530°C and indium cell temperature of 630°C. These dots exhibit strong luminescence and narrow size distribution corresponding to ~70meV full width at half maximum. By investigating the effect of vertical alignment of stacked quantum dots, we were able to show that deposition of second quantum dot layer introduces a blue shift in the luminescence peak. This shift is absent for vertically uncoupled samples. Atomic force microscopy measurements revealed the average size of the quantum dots grown at the surface to be 60 Å in height and base diameter of 120 Å.