Numerical study of optical absorption coefficients in Manning-like AlGaAs/GaAs double quantum wells: Effects of doped impurities

Abstract

We study the electronic and optical properties of a heterostructure based on Manning-like double quantum wells under the impact of an n-doped layer inserted in two different locations. By solving the coupled Schrödinger-Poisson equations, we have determined the four lowest energy levels and their corresponding density of probabilities. After that, we have deduced the optical absorption coefficients between the ground level and each excited state. The study addresses two locations of the doped layer. The first location is at the center of the heterostructure and the second one is at the middle of the right quantum well. The obtained findings show that the energy levels are degenerated when we dope at the center especially for low values of doping concentrations. However, by doping at the right well, we observe a lifting of degeneracy even for low concentrations of the doped layer. Our study demonstrated that the lifting of degeneracy which was absent for low concentrations in the case of doping at the center of the heterostructure can be obtained by adjusting one of the structural parameters of the Manning-like potential. Furthermore, we have discussed in detail the blue and red shifts behaviors observed in the dominant optical absorption coefficients, especially by varying the concentration of the doped layer. Our study confirms that the doping technique stills an excellent strategy to manipulate the electronic and optical properties in quantum wells based on symmetrical shapes.