An Accurate Method of Modeling Self-Assembled InAs/InGaAsP/InP (001) Quantum Dot With Double-Capping Procedure

The double-capping procedure has been widely used to control the size distribution of self-assembled InAs/InGaAsP quantum dots during the growth on a (001) InP substrate. However, the conventional simulation method referred to one-step model does not include this procedure, which may lead to inaccuracy in modeling of quantum dots. An accurate method of modeling a single quantum dot including a thorough elastic strain analysis is proposed and developed in this paper. The confinement potential profiles are found significantly different between the two models. A series of settings (i.e., dot heights, dot base sizes, and dot shapes) is considered. The electronic band structure is calculated by using the eight-band $k \cdot p$ model. By comparing with the photoluminescence measurements in previously published works, it is found that the obtained optical transition energies using the accurate two-step model are in better agreement. The bright exciton splitting is found larger in terms of fine structures. Moreover, the impact of the quaternary compositions (arsenic mole fraction) of barrier material is for the first time systematically studied by using this accurate model.