Simulation of electric-field effect on the optical polarization property of self-assembled indium-arsenide aligned quantum dots

Abstract

The simulation of two-dimensional externally applied electric field system was introduced to implement with self-assembled InAs aligned quantum dots (QDs) in order to investigate the optical polarization property of those QDs. The methodology was based on the numerical finite-difference (FDM) method related to number of grid points, which determines the accuracy of the calculation. From the study, it was found that the linear polarization degree (PD) of the aligned QDs under applied electric filed significantly depends on number of QDs in the system, the field strength, the interdot spacing, and the size of the QDs. The electric filed applied parallel to the alignment of QDs has stronger effect on the degree of optical polarization than that applied in the direction perpendicular to alignment. The aligned QDs manifest good response with an increase of applied field by a larger polarization anisotropy, but turs to decrease in circumstance of strong field. A higher PD value from higher number of QDs was observed and eventually lead to a shife of applied voltage to lower potential, corresponding to maximum PD value. Moreover, very close separation between adjacent QDs also produces a strong polarization. By contrast, the calculation shows a reduction of PD value as enlargement of QDs. From these results, it may be concluded that closer spacing, smaller dot size, more number of QDs in the alignment, and/or suitable magnitude of applied electric field gives rise to a higher polarization degree of aligned QDs structure. The synthesis of results connected to the physics behind them render better understanding and broaden the horizon in the intellectual aspect of thought process, as well. This interesting knowledge would lead to a development in high-efficiency semiconductor optoelectronic devices in the short run.