Calculation of critical size of coherent InAs quantum dot on GaAs substrate

A thermodynamic equilibrium approach is used to simulate the stress field and calculate the total strain energy of InAs/GaAs quantum dots in the framework of anisotropic elasticity, before and after the onset of dislocation. The model can directly calculate the strain energy in the incoherent system with the dislocation forms at any position. Taking the influence of dislocation positions into consideration and based on the energy balance between the coherent and dislocated states, the equilibrium critical size of InAs quantum dots is determined.

Using FEM, 3D models have been built to predict critical size of the InAs/GaAs quantum dot system in the framework of elastic anisotropy.Figure optionsDownload as PowerPoint slideHighlights
► We calculate strain energy in QD before and after the onset of dislocation.
► We use analytical formulas for stress field of dislocation segment as initial stress.
► Based on the finite element method, we calculate the critical size of InAs QD.