The strain relaxation of InAs/GaAs self-organized quantum dot

This paper presents a detailed analysis of the dependence ofdegree of strain relaxation of the self-organized InAs/GaAs quantumdot on the geometrical parameters. Differently shaped quantum dotsarranged with different transverse periods are simulated in thisanalysis. It investigates the total residual strain energy thatstored in the quantum dot and the substrate for all kinds of quantumdots with the same volume, as well as the dependence on both theaspect ratio and transverse period. The calculated results show thatwhen the transverse period is larger than two times the base of thequantum dots, the influence of transverse periods can be ignored.The larger aspect ratio will lead more efficient strain relaxation.The larger angle between the faces and the substrate will lead moreefficient strain relaxation. The obtained results can help tounderstand the shape transition mechanism during the epitaxialgrowth from the viewpoint of energy, because the strain relaxationis the main driving force of the quantum dot's self-organization.