Electron States, Phonon-Assisted Relaxation and Tunneling in Self-Assembled Quantum Dot Molecules in an Electric Field

K. Gawarecki and P. Machnikowski Institute of Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland

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We present a theoretical analysis of the phonon-assisted relaxation in a system composed of two self-assembled vertically stacked quantum dots. We construct realistic model, which takes into account the geometry and strain distribution in the system. We calculate phonon-assisted relaxation rates between the two lowest states (in one- and two-electron cases). The relaxation rates and energy levels are studied as a function of external (axial) electric field and geometry of the structure (dot sizes). We show that the relaxation times can be as low as 1 ps but efficient relaxation occurs only for very finely tuned dots.

DOI: 10.12693/APhysPolA.119.637 PACS numbers: 73.21.La, 73.63.Kv, 63.20.kd