Polaronic mass and non-parabolicity effects on the photoionization cross section of an impurity in a double quantum dot

Abstract

This manuscript focused on the effect of the non-parabolicity and the polaronic mass on the optical and electronic properties in the G a A s − G a 1 − x A l x A s symmetrical double quantum dot (SDQD) of a donor impurity by using the variational method within the effective mass approximation. In this work, we focused our studies on the variation of the binding energy ( E b ) and the photoionization cross section (PICS) as a function of the photon energy, the system size ( L b , L d ) and the impurity position ( x i / L c ) . Our major results show that the E b and the PICS are greatly dependent on the location of the impurity in the SDQD and they are affected by the non-parabolicity effect for strong confinement and by the polaronic mass effect for weak confinement. Furthermore, the modifications in the impurity position, system size, and aluminum concentration can induce a red or blue shift in the resonant peaks of the photoionization cross section. • The binding energy ( E b ) and the photoionization cross section (PICS) depend strongly on the location of the impurity in the G a A s − G a 1 − x A l x A s symmetrical double quantum dot. • E b increases with the presence of non-parabolicity effect as well as combined effect of non-parabolicity and polaronic mass. • Both effects of the non-parabolicity as well as the combined effect of the non-parabolicity & the polaronic mass result in a blue shift in the resonance peak of the PICS. • The E b and the PICS are affected by the non-parabolicity effect for strong confinement and by the polaronic mass effect for weak confinement.