Improved effective one-dimensional electronic structure of InGaAs quantum dot molecules

The one-dimensional (1D) electronic structures, which are based on the solutions of coupled 1D Poisson-Schrödinger equations, are used in simulation of InGaAs quantum dot molecules (QDMs) by considering each quantum dot (QD) as vertical and horizontal structures. The horizontal models has been improved to symmetrical shape which consists of the center of the QD (In_0.77Ga_0.23As) and an intermediate layers (IL) (In_0.6Ga_0.4As) on both sides of the QD symmetrically following spherical shape of quantum dot. The results of the simulation and the effective sizes used in the simulation show good consistence with the ground- and excited-state energies from emission spectra of photoluminescence (PL) measurement and the observed dimensions from atomic force microscope (AFM) images respectively. The more accurate results are obtained by changing the effective sizes at each temperature to explain temperature-dependent characteristics of the QDMs, which possibly arise from thermal effect.