Electronic and Optical Properties of Type Ii Quantum Ring GaAs/Al<sub>x</sub>Ga<sub>1−x</sub>As in Applied Lateral Electric Field

A theoretical study of the effect of applying a lateral electric field on type I and type II GaAs/AlGaAs quantum ring with different Al concentration in the barrier is presented. The effect on the quantum states of the carriers was investigated using the approximation of the effective mass. It’s showed that the electric field has a great effect on the wavefunction and the energy of the carriers. The transition point of the quantum ring from type I to type II was found with increasing electric field strength. For electric fields less than 4.75 x 10 -4 V/cm, the quantum ring is of type II: the symmetry of electron ground state is X. Above this threshold, it transitions to type I : the symmetry of electron ground state is Γ. Also, the effects of electric field on the linear and non-linear optical properties of the studied structure illuminated with different incident optical intensity were studied. There is an increase in the radiative lifetime with a notable decrease in the absorption coefficient and the refractive index with the increase in the intensity of the electric field. It’s noted that the increase in the type II quantum ring lifetime (20%) is greater than that of type I quantum ring (10 %) due to the confinement of the G-electron in the quantum ring which is not the case with the X-electron. To the best of our knowledge, this article is the first theoretical study of the influence of lateral electric field on physical properties of type II GaAs/AlGaAs quantum ring structures.