Influence of position dependent effective mass on impurity binding energy and absorption in quantum wells with the Konwent potential

Abstract

In this work, we perform a theoretical investigation on the effect of position-dependent effective mass on binding energy and optical absorption coefficient for donor impurities in single and double quantum wells defined by Konwent potential. We have used the diagonalization method by choosing a wave function based on the trigonometric orthonormal base functions that are solutions of an infinite square quantum well to get the energy spectrum of the system, the variational method for impurity binding energy is used and also linear absorption coefficient is deduced from the density matrix approach and perturbation expansion method. Numerical results reveal that impurity binding energy as well as the linear optical absorption coefficient are remarkably affected by the confinement potential parameters, position of an impurity and the approach used for the effective electron mass. Moreover, it is seen that with an appropriate choice of the structure parameters and position dependence effective mass distribution, the optical response of the system can be tailored in a controllable manner.