Electronic Structure of Elongated In0.3Ga0.7As/GaAs Quantum Dots

M. Pieczarka, A. Musiał, P. Podemski, G. Sęk and J. Misiewicz Institute of Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland

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In this contribution the electronic structure of large In0.3Ga0.7As/GaAs quantum dots is studied theoretically by means of 8 band k·p modeling. These quantum dots constitute unique physical system due to the low strain limit of the Stranski-Krastanow growth mode resulting in relatively large physical volume and elongation of the quantum dots in [1-10] direction. As a result of these critical growth conditions the electronic structure is expected to be very sensitive to the nanostructure size, shape, and composition of the quantum dot as well as the accompanying wetting layer. Another peculiarity of investigated system is the confining potential which is rather shallow and weakened in comparison to standard quantum dots. It makes them very interesting in view of both fundamental study and potential applications. To reveal physical mechanisms determining the optical properties of the investigated system, the electronic structure, mainly the number of confined states, and the wave function extension as a function of both quantum dot size and geometry have been simulated numerically and the importance of electron-hole Coulomb interactions has been evaluated.

DOI: 10.12693/APhysPolA.124.809 PACS numbers: 78.67.Hc, 73.21.La, 73.22.-f