Optical properties of InAs/GaAs quantum dots grown by epitaxy
Journal
American Society of Mechanical Engineers, Electronic and Photonic Packaging, EPP
Journal Volume
4
Pages
549-554
Date Issued
2004
Author(s)
Abstract
Strain effects on optical properties of self-assembled InAs/GaAs quantum dots grown by epitaxy are investigated. A new model based on the theory of linear elasticity is developed to analyze three-dimensional induced strain field. The model takes sequence of fabrication process of quantum-dot into account, where the mismatch of lattice constants between wetting layer and substrate is treated as initial strain first for the heterostructure system without capping material. The obtained total strain field is then treated as initial strain again for the whole heterostructure system with capping material. The computed strain from these two-steps analysis is then used as an input for the electronic band structure calculation. The numerical results show that strain field from this new model has significant difference from the usual model where the sequence of fabrication process is omitted. The strain-induced potential is incorporated into the three-dimensional steady state effective mass Schro¨dinger equation with the aid of the Pikus-Bir Hamiltonian and Luttinger-Kohn formalism. Both the strain field and the solutions of the steady state Schro¨dinger equations are found numerically by using of a commercial finite element package. The energy levels as well as the wave functions of both conduction and valence bands of quantum dots are calculated. Finally, energy of interband optical transitions is obtained in numerical experiments.
SDGs
Type
conference paper